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Ronca V, Gerussi A, Collins P, Parente A, Oo YH, Invernizzi P. The liver as a central "hub" of the immune system: pathophysiological implications. Physiol Rev 2025; 105:493-539. [PMID: 39297676 DOI: 10.1152/physrev.00004.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 09/05/2024] [Accepted: 09/08/2024] [Indexed: 01/16/2025] Open
Abstract
The purpose of this review is to describe the immune function of the liver, guiding the reader from the homeostatic tolerogenic status to the aberrant activation demonstrated in chronic liver disease. An extensive description of the pathways behind the inflammatory modulation of the healthy liver will be provided focusing on the complex immune cell network residing within the liver. The limit of tolerance will be presented in the context of organ transplantation, seizing the limits of homeostatic mechanisms that fail in accepting the graft, progressing eventually toward rejection. The triggers and mechanisms behind chronic activation in metabolic liver conditions and viral hepatitis will be discussed. The last part of the review will be dedicated to one of the greatest paradoxes for a tolerogenic organ, developing autoimmunity. Through the description of the three most common autoimmune liver diseases, the autoimmune reaction against hepatocytes and biliary epithelial cells will be dissected.
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Affiliation(s)
- Vincenzo Ronca
- Centre for Liver and Gastro Research and National Institute for Health and Care Research (NIHR) Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
- Liver Unit, Queen Elizabeth Hospital University Hospital Birmingham National Health Service (NHS) Foundation Trust, Birmingham, United Kingdom
- Centre for Rare Diseases, European Reference Network Centre-Rare Liver, Birmingham, United Kingdom
- Department of Biomedical Sciences, Humanitas University, Milan, Italy
- Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Humanitas Research Hospital, Milan, Italy
| | - Alessio Gerussi
- Division of Gastroenterology, Center for Autoimmune Liver Diseases, European Reference Network on Hepatological Diseases (ERN RARE-LIVER), IRCCS Fondazione San Gerardo dei Tintori, Monza, Italy
- Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Paul Collins
- VIB-UGent Center for Inflammation Research, Ghent, Belgium
- Department of Biomedical Molecular Biology, Faculty of Sciences, Ghent University, Ghent, Belgium
| | - Alessandro Parente
- Liver Unit, Queen Elizabeth Hospital University Hospital Birmingham National Health Service (NHS) Foundation Trust, Birmingham, United Kingdom
- Institute of Liver Studies, King's College Hospital NHS Foundation Trust, London, United Kingdom
| | - Ye Htun Oo
- Centre for Liver and Gastro Research and National Institute for Health and Care Research (NIHR) Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
- Liver Unit, Queen Elizabeth Hospital University Hospital Birmingham National Health Service (NHS) Foundation Trust, Birmingham, United Kingdom
- Centre for Rare Diseases, European Reference Network Centre-Rare Liver, Birmingham, United Kingdom
| | - Pietro Invernizzi
- Division of Gastroenterology, Center for Autoimmune Liver Diseases, European Reference Network on Hepatological Diseases (ERN RARE-LIVER), IRCCS Fondazione San Gerardo dei Tintori, Monza, Italy
- Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
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Pedersen MR, Mayo MJ. Advances in the evaluation and treatment of autoimmune hepatitis. Curr Opin Gastroenterol 2024; 40:126-133. [PMID: 38363233 DOI: 10.1097/mog.0000000000001014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
PURPOSE OF REVIEW The primary therapy of autoimmune hepatitis (AIH) has been established for over three decades. This review focuses on updates in the evaluation and management of patients with AIH. RECENT FINDINGS The evaluation of patients has recently been updated to include more definitive screening for other autoimmune diseases, including thyroid disease and celiac disease. Antibody detection by ELISA, an easier and more commonly available method, has been incorporated into the latest iteration of the AIH scoring system. Corticosteroids and AZA remain the backbone of AIH treatment, but there is growing evidence for mycophenolate mofetil as both first-line and second-line therapy, and growing inquiry into calcineurin inhibitors. Noninvasive markers of liver disease have now been validated in AIH, with the strongest evidence for VCTE in patients with minimal hepatic inflammation. SUMMARY Recent research of alternative immunosuppressant therapies, noninvasive markers of fibrosis, and updated society guidelines, have improved our ability to evaluate, treat, and follow patients with AIH.
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Affiliation(s)
- M R Pedersen
- Division of Digestive and Liver Disease, University of Texas Southwestern Medical Center, Harry Hines Blvd, Dallas, Texas, USA
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Sîrbe C, Badii M, Crişan TO, Bența G, Grama A, Joosten LAB, Rednic S, Pop TL. Detection of Novel Biomarkers in Pediatric Autoimmune Hepatitis by Proteomic Profiling. Int J Mol Sci 2023; 24:7479. [PMID: 37108648 PMCID: PMC10141667 DOI: 10.3390/ijms24087479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/14/2023] [Accepted: 04/16/2023] [Indexed: 04/29/2023] Open
Abstract
Autoimmune hepatitis (AIH) is characterized by immune-mediated hepatocyte injury resulting in the destruction of liver cells, causing inflammation, liver failure, and fibrosis. Pediatric (AIH) is an autoimmune inflammatory disease that usually requires immunosuppression for an extended period. Frequent relapses after treatment discontinuation demonstrate that current therapies do not control intrahepatic immune processes. This study describes targeted proteomic profiling data in patients with AIH and controls. A total of 92 inflammatory and 92 cardiometabolic plasma markers were assessed for (i) pediatric AIH versus controls, (ii) AIH type 1 versus type 2, (iii) AIH and AIH-autoimmune sclerosing cholangitis overlapping syndrome and (iv) correlations with circulating vitamin D levels in AIH. A total of 16 proteins showed a nominally significant differential abundance in pediatric patients with AIH compared to controls. No clustering of AIH subphenotypes based on all protein data was observed, and no significant correlation of vitamin D levels was observed for the identified proteins. The proteins that showed variable expression include CA1, CA3, GAS6, FCGR2A, 4E-BP1 and CCL19, which may serve as potential biomarkers for patients with AIH. CX3CL1, CXCL10, CCL23, CSF1 and CCL19 showed homology to one another and may be coexpressed in AIH. CXCL10 seems to be the central intermediary link for the listed proteins. These proteins were involved in relevant mechanistic pathways for liver diseases and immune processes in AIH pathogenesis. This is the first report on the proteomic profile of pediatric AIH. The identified markers could potentially lead to new diagnostic and therapeutic tools. Nevertheless, considering the complex pathogenesis of AIH, more extensive studies are warranted to replicate and validate the present study's findings.
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Affiliation(s)
- Claudia Sîrbe
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (C.S.)
- 2nd Pediatric Clinic, Center of Expertise in Pediatric Liver Rare Disorders, Emergency Clinical Hospital for Children, 400177 Cluj-Napoca, Romania
| | - Medeea Badii
- Department of Medical Genetics, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- Department of Internal Medicine, Radboud University Medical Centre, 6525 XZ Nijmegen, The Netherlands
| | - Tania O. Crişan
- Department of Medical Genetics, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- Department of Internal Medicine, Radboud University Medical Centre, 6525 XZ Nijmegen, The Netherlands
| | - Gabriel Bența
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (C.S.)
- 2nd Pediatric Clinic, Center of Expertise in Pediatric Liver Rare Disorders, Emergency Clinical Hospital for Children, 400177 Cluj-Napoca, Romania
| | - Alina Grama
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (C.S.)
- 2nd Pediatric Clinic, Center of Expertise in Pediatric Liver Rare Disorders, Emergency Clinical Hospital for Children, 400177 Cluj-Napoca, Romania
| | - Leo A. B. Joosten
- Department of Internal Medicine, Radboud University Medical Centre, 6525 XZ Nijmegen, The Netherlands
| | - Simona Rednic
- Rheumatology Department, Emergency County Hospital Cluj, 400347 Cluj-Napoca, Romania
- Rheumatology Discipline, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Tudor Lucian Pop
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hațieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (C.S.)
- 2nd Pediatric Clinic, Center of Expertise in Pediatric Liver Rare Disorders, Emergency Clinical Hospital for Children, 400177 Cluj-Napoca, Romania
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Abstract
BACKGROUND Autoimmune hepatitis has an unknown cause and genetic associations that are not disease-specific or always present. Clarification of its missing causality and heritability could improve prevention and management strategies. AIMS Describe the key epigenetic and genetic mechanisms that could account for missing causality and heritability in autoimmune hepatitis; indicate the prospects of these mechanisms as pivotal factors; and encourage investigations of their pathogenic role and therapeutic potential. METHODS English abstracts were identified in PubMed using multiple key search phases. Several hundred abstracts and 210 full-length articles were reviewed. RESULTS Environmental induction of epigenetic changes is the prime candidate for explaining the missing causality of autoimmune hepatitis. Environmental factors (diet, toxic exposures) can alter chromatin structure and the production of micro-ribonucleic acids that affect gene expression. Epistatic interaction between unsuspected genes is the prime candidate for explaining the missing heritability. The non-additive, interactive effects of multiple genes could enhance their impact on the propensity and phenotype of autoimmune hepatitis. Transgenerational inheritance of acquired epigenetic marks constitutes another mechanism of transmitting parental adaptations that could affect susceptibility. Management strategies could range from lifestyle adjustments and nutritional supplements to precision editing of the epigenetic landscape. CONCLUSIONS Autoimmune hepatitis has a missing causality that might be explained by epigenetic changes induced by environmental factors and a missing heritability that might reflect epistatic gene interactions or transgenerational transmission of acquired epigenetic marks. These unassessed or under-evaluated areas warrant investigation.
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Affiliation(s)
- Albert J Czaja
- Mayo Clinic College of Medicine and Science, Rochester, MN, USA.
- Professor Emeritus of Medicine, Mayo Clinic College of Medicine and Science, 200 First Street SW, Rochester, MN, 55905, USA.
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Gerussi A, Halliday N, Carbone M, Invernizzi P, Thorburn D. Open challenges in the management of autoimmune hepatitis. Minerva Gastroenterol (Torino) 2023; 69:61-83. [PMID: 33267568 DOI: 10.23736/s2724-5895.20.02805-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Autoimmune hepatitis (AIH) is a rare autoimmune disease of the liver with many open questions as regards its etiopathogenesis, natural history and clinical management. The classical picture of AIH is chronic hepatitis with fluctuating elevation of serum transaminases and Immunoglobulin G levels, the presence of circulating autoantibodies and typical histological features. However, atypical presentations do occur and are not well captured by current diagnostic scores, with important consequences in terms of missed diagnoses and delayed treatments. AIH is treated with corticosteroids and immunosuppressive drugs but up to 40% of patients do not achieve full biochemical response and are at risk of progressing to cirrhosis and liver failure. Moreover, standard therapies are associated by significant side-effects which may impair the quality of life of patients living with AIH. However, advances in the understanding of the underlying immunology of AIH is raising the prospect of novel therapies and optimization of existing therapeutic approaches to reduce side-effect burdens and potentially restore immunological tolerance. In this review we outlined the clinical characteristics, etiopathogenesis and management of AIH and current challenges in the diagnosis and management of AIH and provided evidence underlying the evolution of diagnostic and clinical management protocols.
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Affiliation(s)
- Alessio Gerussi
- Division of Gastroenterology, Department of Medicine and Surgery, Center for Autoimmune Liver Diseases, University of Milano-Bicocca, Monza, Monza-Brianza, Italy - .,European Reference Network on Hepatological Diseases (ERN RARE-LIVER), San Gerardo Hospital, Monza, Monza-Brianza, Italy - .,Ancient DNA Lab Dan David Center for Human Evolution and Biohistory Research, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel -
| | - Neil Halliday
- Institute for Liver and Digestive Health, University College London, London, UK
| | - Marco Carbone
- Division of Gastroenterology, Department of Medicine and Surgery, Center for Autoimmune Liver Diseases, University of Milano-Bicocca, Monza, Monza-Brianza, Italy.,European Reference Network on Hepatological Diseases (ERN RARE-LIVER), San Gerardo Hospital, Monza, Monza-Brianza, Italy
| | - Pietro Invernizzi
- Division of Gastroenterology, Department of Medicine and Surgery, Center for Autoimmune Liver Diseases, University of Milano-Bicocca, Monza, Monza-Brianza, Italy.,European Reference Network on Hepatological Diseases (ERN RARE-LIVER), San Gerardo Hospital, Monza, Monza-Brianza, Italy
| | - Douglas Thorburn
- Institute for Liver and Digestive Health, University College London, London, UK
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Harsini S, Rezaei N. Autoimmune diseases. Clin Immunol 2023. [DOI: 10.1016/b978-0-12-818006-8.00001-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Lapierre P, Alvarez F. Type 2 autoimmune hepatitis: Genetic susceptibility. Front Immunol 2022; 13:1025343. [PMID: 36248826 PMCID: PMC9556705 DOI: 10.3389/fimmu.2022.1025343] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 09/14/2022] [Indexed: 11/13/2022] Open
Abstract
Two types of autoimmune hepatitis (AIH) are recognized; AIH-1 is characterized by the presence of anti-nuclear and/or anti-smooth muscle autoantibodies, while AIH-2 is associated with the presence of anti-Liver kidney microsome and/or anti-Liver Cytosol antibodies. The autoantigens targeted by AIH-2 autoantibodies are the cytochrome P450 2D6 and Formiminotransferase-cyclodeaminase for anti-LKM1 and anti-LC1 respectively. Both autoantigens are expressed in hepatocytes at higher levels than in any other cell type. Therefore, compared to AIH-1, the autoantigens targeted in AIH-2 are predominantly tissue-specific. Distinct clinical features are specific to AIH-2 compared to AIH-1, including diagnosis in younger patients (mean age 6.6 years), onset as fulminant hepatitis in very young patients (3 years of age or less), higher frequency in children than in adults and is frequently associated with extrahepatic T cell-mediated autoimmune diseases. AIH-2 is also often diagnosed in patients with primary immunodeficiency. AIH-2 is associated with specific HLA class II susceptibility alleles; DQB1*0201 is considered the main determinant of susceptibility while DRB1*07/DRB1*03 is associated with the type of autoantibody present. HLA DQB1*0201 is in strong linkage disequilibrium with both HLA DRB1*03 and DRB1*07. Interestingly, as in humans, MHC and non-MHC genes strongly influence the development of the disease in an animal model of AIH-2. Altogether, these findings suggest that AIH-2 incidence is likely dependent on specific genetic susceptibility factors combined with distinct environmental triggers.
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Affiliation(s)
- Pascal Lapierre
- Laboratoire d’hépatologie cellulaire, Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
- Département de médecine, Université de Montréal, Montréal, QC, Canada
| | - Fernando Alvarez
- Service de gastroentérologie, hépatologie et nutrition, Centre Hospitalier Universitaire (CHU) Sainte-Justine, Montréal, QC, Canada
- Département de Pédiatrie, Université de Montréal, Montréal, QC, Canada
- *Correspondence: Fernando Alvarez,
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Pop TL, Sîrbe C, Benţa G, Mititelu A, Grama A. The Role of Vitamin D and Vitamin D Binding Protein in Chronic Liver Diseases. Int J Mol Sci 2022; 23:10705. [PMID: 36142636 PMCID: PMC9503777 DOI: 10.3390/ijms231810705] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/09/2022] [Accepted: 09/12/2022] [Indexed: 11/24/2022] Open
Abstract
Vitamin D (calciferol) is a fat-soluble vitamin that has a significant role in phospho-calcium metabolism, maintaining normal calcium levels and bone health development. The most important compounds of vitamin D are cholecalciferol (vitamin D3, or VD3) and ergocalciferol (vitamin D2, or VD2). Besides its major role in maintaining an adequate level of calcium and phosphate concentrations, vitamin D is involved in cell growth and differentiation and immune function. Recently, the association between vitamin D deficiency and the progression of fibrosis in chronic liver disease (CLD) was confirmed, given the hepatic activation process and high prevalence of vitamin D deficiency in these diseases. There are reports of vitamin D deficiency in CLD regardless of the etiology (chronic viral hepatitis, alcoholic cirrhosis, non-alcoholic fatty liver disease, primary biliary cirrhosis, or autoimmune hepatitis). Vitamin D binding protein (VDBP) is synthesized by the liver and has the role of binding and transporting vitamin D and its metabolites to the target organs. VDBP also plays an important role in inflammatory response secondary to tissue damage, being involved in the degradation of actin. As intense research during the last decades revealed the possible role of vitamin D in liver diseases, a deeper understanding of the vitamin D, vitamin D receptors (VDRs), and VDBP involvement in liver inflammation and fibrogenesis could represent the basis for the development of new strategies for diagnosis, prognosis, and treatment of liver diseases. This narrative review presents an overview of the evidence of the role of vitamin D and VDBP in CLD, both at the experimental and clinical levels.
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Affiliation(s)
- Tudor Lucian Pop
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- 2nd Pediatric Clinic, Emergency Clinical Hospital for Children, 400177 Cluj-Napoca, Romania
| | - Claudia Sîrbe
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Gabriel Benţa
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Alexandra Mititelu
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Alina Grama
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- 2nd Pediatric Clinic, Emergency Clinical Hospital for Children, 400177 Cluj-Napoca, Romania
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Sîrbe C, Rednic S, Grama A, Pop TL. An Update on the Effects of Vitamin D on the Immune System and Autoimmune Diseases. Int J Mol Sci 2022; 23:9784. [PMID: 36077185 PMCID: PMC9456003 DOI: 10.3390/ijms23179784] [Citation(s) in RCA: 119] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 08/24/2022] [Accepted: 08/26/2022] [Indexed: 12/16/2022] Open
Abstract
Vitamin D intervenes in calcium and phosphate metabolism and bone homeostasis. Experimental studies have shown that 1,25-dihydroxyvitamin D (calcitriol) generates immunologic activities on the innate and adaptive immune system and endothelial membrane stability. Low levels of serum 25-hydroxyvitamin D (25(OH)D) are associated with an increased risk of developing immune-related diseases such as psoriasis, type 1 diabetes, multiple sclerosis, and autoimmune diseases. Various clinical trials describe the efficacy of supplementation of vitamin D and its metabolites for treating these diseases that result in variable outcomes. Different disease outcomes are observed in treatment with vitamin D as high inter-individual difference is present with complex gene expression in human peripheral blood mononuclear cells. However, it is still not fully known what level of serum 25(OH)D is needed. The current recommendation is to increase vitamin D intake and have enough sunlight exposure to have serum 25(OH)D at a level of 30 ng/mL (75 nmol/L) and better at 40-60 ng/mL (100-150 nmol/L) to obtain the optimal health benefits of vitamin D.
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Affiliation(s)
- Claudia Sîrbe
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- 2nd Pediatric Clinic, Emergency Clinical Hospital for Children, 400177 Cluj-Napoca, Romania
| | - Simona Rednic
- Rheumatology Department, Emergency County Hospital Cluj, 400347 Cluj-Napoca, Romania
- Rheumatology Discipline, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Alina Grama
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- 2nd Pediatric Clinic, Emergency Clinical Hospital for Children, 400177 Cluj-Napoca, Romania
| | - Tudor Lucian Pop
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- 2nd Pediatric Clinic, Emergency Clinical Hospital for Children, 400177 Cluj-Napoca, Romania
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10
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Czaja AJ. Epigenetic Aspects and Prospects in Autoimmune Hepatitis. Front Immunol 2022; 13:921765. [PMID: 35844554 PMCID: PMC9281562 DOI: 10.3389/fimmu.2022.921765] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 05/12/2022] [Indexed: 12/12/2022] Open
Abstract
The observed risk of autoimmune hepatitis exceeds its genetic risk, and epigenetic factors that alter gene expression without changing nucleotide sequence may help explain the disparity. Key objectives of this review are to describe the epigenetic modifications that affect gene expression, discuss how they can affect autoimmune hepatitis, and indicate prospects for improved management. Multiple hypo-methylated genes have been described in the CD4+ and CD19+ T lymphocytes of patients with autoimmune hepatitis, and the circulating micro-ribonucleic acids, miR-21 and miR-122, have correlated with laboratory and histological features of liver inflammation. Both epigenetic agents have also correlated inversely with the stage of liver fibrosis. The reduced hepatic concentration of miR-122 in cirrhosis suggests that its deficiency may de-repress the pro-fibrotic prolyl-4-hydroxylase subunit alpha-1 gene. Conversely, miR-155 is over-expressed in the liver tissue of patients with autoimmune hepatitis, and it may signify active immune-mediated liver injury. Different epigenetic findings have been described in diverse autoimmune and non-autoimmune liver diseases, and these changes may have disease-specificity. They may also be responses to environmental cues or heritable adaptations that distinguish the diseases. Advances in epigenetic editing and methods for blocking micro-ribonucleic acids have improved opportunities to prove causality and develop site-specific, therapeutic interventions. In conclusion, the role of epigenetics in affecting the risk, clinical phenotype, and outcome of autoimmune hepatitis is under-evaluated. Full definition of the epigenome of autoimmune hepatitis promises to enhance understanding of pathogenic mechanisms and satisfy the unmet clinical need to improve therapy for refractory disease.
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Affiliation(s)
- Albert J. Czaja
- *Correspondence: Albert J. Czaja, ; orcid.org/0000-0002-5024-3065
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11
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Sirbe C, Simu G, Szabo I, Grama A, Pop TL. Pathogenesis of Autoimmune Hepatitis-Cellular and Molecular Mechanisms. Int J Mol Sci 2021; 22:13578. [PMID: 34948375 PMCID: PMC8703580 DOI: 10.3390/ijms222413578] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 12/09/2021] [Accepted: 12/14/2021] [Indexed: 02/05/2023] Open
Abstract
Pediatric autoimmune liver disorders include autoimmune hepatitis (AIH), autoimmune sclerosing cholangitis (ASC), and de novo AIH after liver transplantation. AIH is an idiopathic disease characterized by immune-mediated hepatocyte injury associated with the destruction of liver cells, causing inflammation, liver failure, and fibrosis, typically associated with autoantibodies. The etiology of AIH is not entirely unraveled, but evidence supports an intricate interaction among genetic variants, environmental factors, and epigenetic modifications. The pathogenesis of AIH comprises the interaction between specific genetic traits and molecular mimicry for disease development, impaired immunoregulatory mechanisms, including CD4+ T cell population and Treg cells, alongside other contributory roles played by CD8+ cytotoxicity and autoantibody production by B cells. These findings delineate an intricate pathway that includes gene to gene and gene to environment interactions with various drugs, viral infections, and the complex microbiome. Epigenetics emphasizes gene expression through hereditary and reversible modifications of the chromatin architecture without interfering with the DNA sequence. These alterations comprise DNA methylation, histone transformations, and non-coding small (miRNA) and long (lncRNA) RNA transcriptions. The current first-line therapy comprises prednisolone plus azathioprine to induce clinical and biochemical remission. Further understanding of the cellular and molecular mechanisms encountered in AIH may depict their impact on clinical aspects, detect biomarkers, and guide toward novel, effective, and better-targeted therapies with fewer side effects.
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Affiliation(s)
- Claudia Sirbe
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (C.S.); (T.L.P.)
- 2nd Pediatric Clinic, Emergency Clinical Hospital for Children, 400177 Cluj-Napoca, Romania
| | - Gelu Simu
- Cardiology Department, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania;
- Cardiology Department, Rehabilitation Hospital, 400066 Cluj-Napoca, Romania
| | - Iulia Szabo
- Department of Rheumatology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania;
| | - Alina Grama
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (C.S.); (T.L.P.)
- 2nd Pediatric Clinic, Emergency Clinical Hospital for Children, 400177 Cluj-Napoca, Romania
| | - Tudor Lucian Pop
- 2nd Pediatric Discipline, Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania; (C.S.); (T.L.P.)
- 2nd Pediatric Clinic, Emergency Clinical Hospital for Children, 400177 Cluj-Napoca, Romania
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12
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Association between FAS gene -670 A/G and -1377 G/A polymorphisms and the risk of autoimmune diseases: a meta-analysis. Biosci Rep 2021; 40:221503. [PMID: 31840751 PMCID: PMC6944657 DOI: 10.1042/bsr20191197] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 12/03/2019] [Accepted: 12/13/2019] [Indexed: 12/16/2022] Open
Abstract
Objectives: FAS plays a critical role in the extrinsic apoptosis pathway in autoimmune diseases. Previous studies investigating the association between FAS gene −670 A/G and −1377 G/A polymorphisms and the risk of autoimmune diseases reported controversial results. We performed the meta-analysis to evaluate the possible association. Methods: Relevant studies were identified by searching the PubMed, Embase, CNKI, and Wanfang databases up to December 2018. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to determine the association. Results: A total of 43 articles including 67 studies (52 studies for FAS −670 A/G and 15 studies for −1377 G/A) were included in the meta-analysis. Our meta-analysis showed that the FAS −670 A/G polymorphism was associated with the risk of autoimmune diseases (GG vs. GA: OR = 1.079, 95% CI = 1.004–1.160, P=0.038), especially in Caucasians (GG vs. GA: OR = 1.12, 95% CI = 1.03–1.23, P=0.012), Asians (G vs. A: OR = 0.89, 95% CI = 0.83–0.96, P=0.002), systemic lupus erythematosus (SLE) (G vs. A: OR = 0.85, 95% CI = 0.77–0.94, P=0.001), multiple sclerosis (MS) (GG+GA vs. AA: OR = 0.83, 95% CI = 0.70–0.99, P=0.043), systemic sclerosis (SSc) (GG vs. GA: OR = 1.20, 95% CI = 1.07–1.36, P=0.003) and Hashimoto’s thyroiditis (HT) (G vs. A: OR = 1.45, 95% CI = 1.10–1.90, P=0.008); the FAS −1377 G/A polymorphism was associated with the risk of autoimmune diseases (A vs. G: OR = 1.11, 95% CI = 1.03–1.20, P=0.008), especially in Asians (A vs. G: OR = 1.15, 95% CI = 1.05–1.25, P=0.002) and high quality studies (A vs. G: OR = 1.14, 95% CI = 1.05–1.24, P=0.002). Conclusion: This meta-analysis demonstrated that the FAS –670A/G and –1377 G/A polymorphisms were associated with the risk of autoimmune diseases.
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13
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Higuchi T, Oka S, Furukawa H, Tohma S, Yatsuhashi H, Migita K. Genetic risk factors for autoimmune hepatitis: implications for phenotypic heterogeneity and biomarkers for drug response. Hum Genomics 2021; 15:6. [PMID: 33509297 PMCID: PMC7841991 DOI: 10.1186/s40246-020-00301-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 12/15/2020] [Indexed: 01/10/2023] Open
Abstract
Autoimmune hepatitis (AIH) is a rare chronic progressive liver disease with autoimmune features. It mainly affects middle-aged women. AIH is occasionally complicated with liver cirrhosis that worsens the prognosis. Genetic and environmental factors are involved in the pathogenesis of AIH. Genetic studies of other diseases have been revealing of pathogenesis and drug efficacy. In this review, we summarize the genetic risk factors for AIH, including human leukocyte antigen (HLA) and non-HLA genes. A genome-wide association study (GWAS) on European AIH revealed the strongest associations to be with single nucleotide variants (SNVs) in HLA. Predisposing alleles for AIH were DRB1*03:01 and DRB1*04:01 in Europeans; DRB1*04:04, DRB1*04:05, and DRB1*13:01 in Latin Americans; and DRB1*04:01 and DRB1*04:05 in Japanese. Other risk SNVs in non-HLA genes for AIH were found by a candidate gene approach, but several SNVs were confirmed in replication studies. Some genetic factors of AIH overlapped with those of other autoimmune diseases. Larger-scale GWASs of other ethnic groups are required. The results of genetic studies might provide an explanation for the phenotypic heterogeneity of AIH and biomarkers for drug responses.
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Affiliation(s)
- Takashi Higuchi
- Molecular and Genetic Epidemiology Laboratory, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan.,Department of Nephrology, Ushiku Aiwa General Hospital, 896 Shishiko-cho, Ushiku, 300-1296, Japan.,Department of Rheumatology, National Hospital Organization Tokyo National Hospital, 3-1-1 Takeoka, Kiyose, 204-8585, Japan
| | - Shomi Oka
- Molecular and Genetic Epidemiology Laboratory, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan.,Department of Rheumatology, National Hospital Organization Tokyo National Hospital, 3-1-1 Takeoka, Kiyose, 204-8585, Japan.,Clinical Research Center for Allergy and Rheumatology, National Hospital Organization Sagamihara National Hospital, 18-1 Sakuradai, Minami-ku, Sagamihara, 252-0392, Japan
| | - Hiroshi Furukawa
- Molecular and Genetic Epidemiology Laboratory, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan. .,Department of Rheumatology, National Hospital Organization Tokyo National Hospital, 3-1-1 Takeoka, Kiyose, 204-8585, Japan. .,Clinical Research Center for Allergy and Rheumatology, National Hospital Organization Sagamihara National Hospital, 18-1 Sakuradai, Minami-ku, Sagamihara, 252-0392, Japan.
| | - Shigeto Tohma
- Department of Rheumatology, National Hospital Organization Tokyo National Hospital, 3-1-1 Takeoka, Kiyose, 204-8585, Japan.,Clinical Research Center for Allergy and Rheumatology, National Hospital Organization Sagamihara National Hospital, 18-1 Sakuradai, Minami-ku, Sagamihara, 252-0392, Japan
| | - Hiroshi Yatsuhashi
- Clinical Research Center, National Hospital Organization Nagasaki Medical Center, 2-1001-1 Kubara, Omura, 856-8562, Japan
| | - Kiyoshi Migita
- Clinical Research Center, National Hospital Organization Nagasaki Medical Center, 2-1001-1 Kubara, Omura, 856-8562, Japan.,Department of Rheumatology, Fukushima Medical University School of Medicine, 1 Hikarigaoka, Fukushima, 960-1295, Japan
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14
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Halliday N, Dyson JK, Thorburn D, Lohse AW, Heneghan MA. Review article: experimental therapies in autoimmune hepatitis. Aliment Pharmacol Ther 2020; 52:1134-1149. [PMID: 32794592 DOI: 10.1111/apt.16035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 03/02/2020] [Accepted: 07/22/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Current therapeutic options for autoimmune hepatitis (AIH) are limited by adverse events associated with corticosteroids and thiopurines and the limited evidence base for second- and third-line treatment options. Furthermore, current treatment approaches require long-term exposure of patients to pharmacological agents. There have been significant advances in the understanding of the mechanisms underpinning autoimmunity and an expansion in the available therapeutic agents for suppressing autoimmune responses or potentially restoring self-tolerance. AIM To review the mechanisms and evidence for experimental therapies that are being actively explored in the management of AIH. METHODS We have reviewed the literature relating to a range of novel therapeutic immunomodulatory treatment strategies and drugs. RESULTS Drugs which block B cell-activating factor of the tumour necrosis factor family (BAFF) and tumour necrosis factor α are currently in clinical trials for the treatment of AIH. Experimental therapies and technologies to increase immune tolerance, such as pre-implantation factor and regulatory T cell therapies, are undergoing development for application in autoimmune disorders. There is also evidence for targeting inflammatory pathways to control other autoimmune conditions, such as blockade of IL1 and IL6 and Janus-associated kinase (JAK) inhibitors. CONCLUSIONS With the range of tools available to clinicians and patients increasing, it is likely that the therapeutic landscape of AIH will change over the coming years and treatment approaches offering lower corticosteroid use and aiming to restore immune self-tolerance should be sought.
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Affiliation(s)
- Neil Halliday
- Institute of Liver and Digestive Health, University College London, London, UK.,The Sheila Sherlock Liver Centre, Royal Free Hospital, London, UK
| | - Jessica Katharine Dyson
- Translational and Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, UK.,Hepatology Department, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, UK
| | - Douglas Thorburn
- Institute of Liver and Digestive Health, University College London, London, UK.,The Sheila Sherlock Liver Centre, Royal Free Hospital, London, UK
| | - Ansgar W Lohse
- Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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15
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Mack CL, Adams D, Assis DN, Kerkar N, Manns MP, Mayo MJ, Vierling JM, Alsawas M, Murad MH, Czaja AJ. Diagnosis and Management of Autoimmune Hepatitis in Adults and Children: 2019 Practice Guidance and Guidelines From the American Association for the Study of Liver Diseases. Hepatology 2020; 72:671-722. [PMID: 31863477 DOI: 10.1002/hep.31065] [Citation(s) in RCA: 548] [Impact Index Per Article: 109.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 11/25/2019] [Indexed: 02/06/2023]
Affiliation(s)
- Cara L Mack
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO
| | - David Adams
- Centre for Liver Research, University of Birmingham, Birmingham, UK
| | - David N Assis
- Department of Internal Medicine, Yale School of Medicine, New Haven, CT
| | - Nanda Kerkar
- Golisano Children's Hospital at Strong, University of Rochester Medical Center, New York, NY
| | - Michael P Manns
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Marlyn J Mayo
- Division of Digestive and Liver Diseases, University of Texas SW Medical Center, Dallas, TX
| | - John M Vierling
- Medicine and Surgery, Baylor College of Medicine, Houston, TX
| | | | - Mohammad H Murad
- Mayo Knowledge and Encounter Research Unit, Mayo Clinic College of Medicine, Rochester, MN
| | - Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN
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16
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Czaja AJ. Examining pathogenic concepts of autoimmune hepatitis for cues to future investigations and interventions. World J Gastroenterol 2019; 25:6579-6606. [PMID: 31832000 PMCID: PMC6906207 DOI: 10.3748/wjg.v25.i45.6579] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 11/25/2019] [Accepted: 11/29/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Multiple pathogenic mechanisms have been implicated in autoimmune hepatitis, but they have not fully explained susceptibility, triggering events, and maintenance or escalation of the disease. Furthermore, they have not identified a critical defect that can be targeted. The goals of this review are to examine the diverse pathogenic mechanisms that have been considered in autoimmune hepatitis, indicate investigational opportunities to validate their contribution, and suggest interventions that might evolve to modify their impact. English abstracts were identified in PubMed by multiple search terms. Full length articles were selected for review, and secondary and tertiary bibliographies were developed. Genetic and epigenetic factors can affect susceptibility by influencing the expression of immune regulatory genes. Thymic dysfunction, possibly related to deficient production of programmed cell death protein-1, can allow autoreactive T cells to escape deletion, and alterations in the intestinal microbiome may help overcome immune tolerance and affect gender bias. Environmental factors may trigger the disease or induce epigenetic changes in gene function. Molecular mimicry, epitope spread, bystander activation, neo-antigen production, lymphocytic polyspecificity, and disturbances in immune inhibitory mechanisms may maintain or escalate the disease. Interventions that modify epigenetic effects on gene expression, alter intestinal dysbiosis, eliminate deleterious environmental factors, and target critical pathogenic mechanisms are therapeutic possibilities that might reduce risk, individualize management, and improve outcome. In conclusion, diverse pathogenic mechanisms have been implicated in autoimmune hepatitis, and they may identify a critical factor or sequence that can be validated and used to direct future management and preventive strategies.
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Affiliation(s)
- Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine and Science, Rochester, MN 55905, United States
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17
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Chen RL, Wang QX, Ma X. Precision medicine for autoimmune hepatitis. J Dig Dis 2019; 20:331-337. [PMID: 31099976 DOI: 10.1111/1751-2980.12786] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 05/07/2019] [Indexed: 01/10/2023]
Abstract
Autoimmune hepatitis (AIH) is an autoimmune liver disease induced by environmental factors in genetically susceptible individuals. AIH is characterized by hypergammaglobulinemia, elevation of serum autoantibodies and transaminases, and interface hepatitis. Personalized therapy is necessary in AIH because of its heterogeneity in clinical manifestations. Precision medicine is a recent and novel therapeutic pattern which ultimately aims to achieve personalized therapy. In this review we summarize the research progress of precision medicine to treat AIH by an exploration of the susceptible genes, precision diagnosis and prognosis of AIH, pharmacogenomics and precision medication, and the precision treatment for special types of AIH.
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Affiliation(s)
- Rui Ling Chen
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Qi Xia Wang
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xiong Ma
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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18
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Webb GJ, Hirschfield GM, Krawitt EL, Gershwin ME. Cellular and Molecular Mechanisms of Autoimmune Hepatitis. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2019; 13:247-292. [PMID: 29140756 DOI: 10.1146/annurev-pathol-020117-043534] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Autoimmune hepatitis is an uncommon idiopathic syndrome of immune-mediated destruction of hepatocytes, typically associated with autoantibodies. The disease etiology is incompletely understood but includes a clear association with human leukocyte antigen (HLA) variants and other non-HLA gene variants, female sex, and the environment. Pathologically, there is a CD4+ T cell-rich lymphocytic inflammatory infiltrate with variable hepatocyte necrosis and subsequent hepatic fibrosis. Attempts to understand pathogenesis are informed by several monogenetic syndromes that may include autoimmune liver injury, by several drug and environmental agents that have been identified as triggers in a minority of cases, by human studies that point toward a central role for CD4+ effector and regulatory T cells, and by animal models of the disease. Nonspecific immunosuppression is the current standard therapy. Further understanding of the disease's cellular and molecular mechanisms may assist in the design of better-targeted therapies, aid the limitation of adverse effects from therapy, and inform individualized risk assessment and prognostication.
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Affiliation(s)
- G J Webb
- National Institute for Health Research Liver Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, United Kingdom; ,
| | - G M Hirschfield
- National Institute for Health Research Liver Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, United Kingdom; ,
| | - E L Krawitt
- Department of Medicine, University of Vermont, Burlington, Vermont 05405, USA; .,Department of Medicine, Dartmouth College, Hanover, New Hampshire 03755, USA
| | - M E Gershwin
- Division of Rheumatology, Allergy, and Clinical Immunology, School of Medicine, University of California, Davis, California 95817, USA;
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19
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Christen U, Hintermann E. Pathogens and autoimmune hepatitis. Clin Exp Immunol 2018; 195:35-51. [PMID: 30113082 DOI: 10.1111/cei.13203] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 07/30/2018] [Accepted: 08/06/2018] [Indexed: 12/12/2022] Open
Abstract
Autoimmune hepatitis (AIH) is a severe form of hepatitis resulting in the autoimmune-mediated destruction of the liver parenchyma. Whereas many of the immunopathogenic events have been elucidated and some of the drivers of the disease have been identified, little is known about the aetiology of the disease. There are certain risk factors, such as particular human leucocyte antigen (HLA) haplotypes, that enhance the susceptibility for AIH or influence the severity of the disease. However, as for many other autoimmune diseases, the mere presence of such risk factors does not warrant the occurrence of the disease. Not all individuals carrying risk factors develop AIH, and not all patients with AIH are carriers of high-risk alleles. Thus, additional environmental factors need to be considered as triggers for AIH. Environmental factors include diet, sunlight exposure, stress, medication and hygiene, as well as pathogen infections and vaccinations. This review discusses if pathogens should be considered as triggers for the initiation and/or propagation of AIH.
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Affiliation(s)
- U Christen
- Pharmazentrum Frankfurt / ZAFES, Goethe University Hospital, Frankfurt am Main, Germany
| | - E Hintermann
- Pharmazentrum Frankfurt / ZAFES, Goethe University Hospital, Frankfurt am Main, Germany
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20
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Liver immunology: How to reconcile tolerance with autoimmunity. Clin Res Hepatol Gastroenterol 2017; 41:6-16. [PMID: 27526967 DOI: 10.1016/j.clinre.2016.06.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 06/01/2016] [Indexed: 02/04/2023]
Abstract
There are several examples of liver tolerance: the relative ease by which liver allografts are accepted and the exploitation of the hepatic microenvironment by the malarial parasite and hepatotrophic viruses are notable examples. The vasculature of the liver supports a unique population of antigen presenting cells specialised to maintain immunological tolerance despite continuous exposure to gut-derived antigens. Liver sinusoidal endothelial cells and Kupffer cells appear to be key to the maintenance of immune tolerance, by promoting T cell anergy or deletion and the generation of regulatory cell subsets. Despite this, there are three liver diseases with likely autoimmune involvement: primary biliary cirrhosis, primary sclerosing cholangitis and autoimmune hepatitis. How can we reconcile this with the inherent tolerogenicity of the liver? Genetic studies have uncovered several associations with genes involved in the activation of the innate and adaptive immune systems. There is also evidence pointing to pathogenic and xenobiotic triggers of autoimmune liver disease. Coupled to this, impaired immunoregulatory mechanisms potentially play a permissive role, allowing the autoimmune response to proceed.
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21
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Liberal R, Grant CR. Cirrhosis and autoimmune liver disease: Current understanding. World J Hepatol 2016; 8:1157-1168. [PMID: 27729952 PMCID: PMC5055585 DOI: 10.4254/wjh.v8.i28.1157] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 05/14/2016] [Accepted: 08/08/2016] [Indexed: 02/06/2023] Open
Abstract
Primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH) constitute the classic autoimmune liver diseases (AILDs). While AIH target the hepatocytes, in PBC and PSC the targets of the autoimmune attack are the biliary epithelial cells. Persistent liver injury, associated with chronic AILD, leads to un-resolving inflammation, cell proliferation and the deposition of extracellular matrix proteins by hepatic stellate cells and portal myofibroblasts. Liver cirrhosis, and the resultant loss of normal liver function, inevitably ensues. Patients with cirrhosis have higher risks or morbidity and mortality, and that in the decompensated phase, complications of portal hypertension and/or liver dysfunction lead to rapid deterioration. Accurate diagnosis and monitoring of cirrhosis is, therefore of upmost importance. Liver biopsy is currently the gold standard technique, but highly promising non-invasive methodology is under development. Liver transplantation (LT) is an effective therapeutic option for the management of end-stage liver disease secondary to AIH, PBC and PSC. LT is indicated for AILD patients who have progressed to end-stage chronic liver disease or developed intractable symptoms or hepatic malignancy; in addition, LT may also be indicated for patients presenting with acute liver disease due to AIH who do not respond to steroids.
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22
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Liberal R, Mieli-Vergani G, Vergani D. Contemporary issues and future directions in autoimmune hepatitis. Expert Rev Gastroenterol Hepatol 2016; 10:1163-1174. [PMID: 27215278 DOI: 10.1080/17474124.2016.1193004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Autoimmune hepatitis (AIH) is a severe life-threatening hepatopathy of unknown etiology, affecting both pediatric and adult populations, and characterised by inflammatory liver histology, circulating non-organ-specific autoantibodies, and hypergammaglobulinaemia. AIH is a very heterogeneous disease with a variety of clinical presentations, ranging from asymptomatic liver test abnormalities to acute severe hepatitis or even acute liver failure. It responds very well to immunosuppressive treatment with prednisolone with or without azathioprine. Patients who are intolerant or fail to respond to standard therapy are candidates for alternative immunosuppressive regimens, the combination of steroids with mycophenolate mofetil or calcineurin inhibitors being the most frequently reported. The pathogenesis of AIH remains not completely understood, although there is evidence that genetic predisposition, molecular mimicry and defective immunoregulatory mechanisms contribute to the autoimmune liver damage. Areas covered: A literature search was conducted using the key-words 'autoimmune hepatitis', 'immunogenetics', 'regulatory T-cells' and 'immunosuppression'. The aim of this review is to discuss recent breakthroughs in the understanding AIH pathogenesis, diagnosis and treatment. Expert commentary: Progress in the understanding of AIH pathogenesis is likely to contribute to the development of novel therapeutic strategies, such as the adoptive transfer of autologous expanded antigen-specific regulatory T-cells.
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Affiliation(s)
- Rodrigo Liberal
- a Institute of Liver Studies and Paediatric Liver, GI & Nutrition Centre , King's College Hospital , London , UK
| | - Giorgina Mieli-Vergani
- a Institute of Liver Studies and Paediatric Liver, GI & Nutrition Centre , King's College Hospital , London , UK
| | - Diego Vergani
- a Institute of Liver Studies and Paediatric Liver, GI & Nutrition Centre , King's College Hospital , London , UK
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23
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Liberal R, Mieli-Vergani G, Vergani D. Autoimmune hepatitis: From mechanisms to therapy. Rev Clin Esp 2016. [DOI: 10.1016/j.rceng.2016.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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24
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Liberal R, Mieli-Vergani G, Vergani D. Autoimmune hepatitis: From mechanisms to therapy. Rev Clin Esp 2016; 216:372-383. [PMID: 27161382 DOI: 10.1016/j.rce.2016.04.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 04/02/2016] [Indexed: 12/13/2022]
Abstract
Autoimmune hepatitis (AIH) is a progressive inflammatory hepatopathy and an important cause of end-stage liver disease. Its aetiology remains unknown, though both genetic and environmental factors are involved in its development. The major mechanism of autoimmune liver damage involves immune reactions against host liver antigens. Numerical and functional defects of regulatory T-cells play a permissive role enabling autoimmune liver injury to occur and persist. The most typical features of AIH are female preponderance, hypergammaglobulinaemia, seropositivity for circulating autoantibodies and a picture of interface hepatitis on histology. Two types of AIH are distinguished according to serological profile: AIH type 1 patients are positive for anti-nuclear and/or anti-smooth muscle antibodies, whereas AIH type 2 patients are defined by the positivity for anti-liver kidney microsomal type 1 antibody and/or for anti-liver cytosol type 1 antibody. Clinical manifestations are variable, and AIH onset is often ill-defined, frequently mimicking acute hepatitis; its course may be fluctuating. AIH responds to immunosuppressive treatment in the majority of cases. Steroids with or without azathioprine should be instituted promptly upon diagnosis. Remission is achieved in some 80% of patients. For the remaining 20% of patients, alternative immunosuppressive agents such as mycophenolate mofetil and calcineurin inhibitors are an option. Liver transplantation should be considered for those patients who progress to cirrhosis and develop complications of end-stage liver disease, as well as for those presenting with acute liver failure; outcomes are excellent, although the disease may recur in the allograft.
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Affiliation(s)
- R Liberal
- Institute of Liver Studies, King's College London, Faculty of Life Sciences & Medicine, London, UK; Department of Gastroenterology, Centro Hospitalar São João and Faculty of Medicine, University of Porto, Porto, Portugal
| | - G Mieli-Vergani
- Institute of Liver Studies, King's College London, Faculty of Life Sciences & Medicine, London, UK; Paediatric Liver, GI & Nutrition Centre, King's College Hospital, London, UK
| | - D Vergani
- Institute of Liver Studies, King's College London, Faculty of Life Sciences & Medicine, London, UK.
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25
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Genetic factors affect the etiology, clinical characteristics and outcome of autoimmune hepatitis. Clin J Gastroenterol 2015; 8:360-6. [DOI: 10.1007/s12328-015-0620-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 11/19/2015] [Indexed: 02/06/2023]
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26
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Mohammadi A, Tajik N, Shah-Hosseini A, Alavian SM, Sharifi Z, Jarahi L. FAS and FAS-Ligand Promoter Polymorphisms in Hepatitis B Virus Infection. HEPATITIS MONTHLY 2015; 15:e26490. [PMID: 26587033 PMCID: PMC4644599 DOI: 10.5812/hepatmon.26490] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 06/12/2015] [Accepted: 08/12/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND The FAS and FAS-Ligand (FASL) system is an important apoptosis pathway in the liver. The FAS-mediated pathway functions by binding the FASL on the activated cytotoxic T lymphocytes and Natural Killer (NK) cells to the FAS receptor on infected hepatocytes. FAS and FASL polymorphisms, which are related to apoptosis, might influence the outcome of Hepatitis B Virus (HBV) infection. OBJECTIVES Thus, the present study aimed to determine if FAS and FASL promoter polymorphisms are associated with the clinical outcome of HBV infection. PATIENTS AND METHODS DNA samples were obtained from the infected individuals including chronic carrier (n = 50), chronic hepatitis (n = 50), cirrhosis (n = 25), naturally recovered (n = 26) and compared with those of their matched healthy controls (n = 100). Genotyping for polymorphisms of FAS-670 A/G and -1377 G/A, and FASL -844 C/T was performed using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assays. RESULTS Multiple analyses for genetic association of FAS and FASL polymorphisms were not statistically different between HBV patients (n = 125) and healthy controls (n = 100). However, genotype and allele frequencies of FASL-844 C/T were significantly different between recovered individuals and patients with cirrhosis (P = 0.02 and P=0.01, respectively). Whereas, FAS-670A/G and -1377G/A polymorphisms were similarly distributed in these two groups (P = 0.8 and P = 0.47, respectively). CONCLUSIONS The current study results showed that bearing -844T allele in FASL promoter region has a protective effect on cirrhosis and is involved in recovery from infection. In conclusion, it is proposed that HBV infection outcome might be influenced by FASL-844C/T polymorphism through alteration in apoptosis of hepatocytes.
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Affiliation(s)
- Asadollah Mohammadi
- Immunology Research Center (IRC), Iran University of Medical Sciences, Tehran, IR Iran
| | - Nader Tajik
- Immunology Research Center (IRC), Iran University of Medical Sciences, Tehran, IR Iran
- Corresponding Author: Nader Tajik, Immunology Research Center (IRC), Iran University of Medical Sciences, Tehran, IR Iran. Tel: +98-9123250344, Fax: +98-2188622652, E-mail:
| | - Alireza Shah-Hosseini
- Immunology Research Center (IRC), Iran University of Medical Sciences, Tehran, IR Iran
| | - Seyed Moayed Alavian
- Baqiyatallah Research Center for Gastroenterology and Liver Diseases, Baqiyatallah University of Medical Sciences, Tehran, IR Iran
| | - Zohreh Sharifi
- Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, IR Iran
| | - Lida Jarahi
- Community Medicine Department, Addiction Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, IR Iran
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Czaja AJ. Transitioning from Idiopathic to Explainable Autoimmune Hepatitis. Dig Dis Sci 2015; 60:2881-900. [PMID: 25999246 DOI: 10.1007/s10620-015-3708-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 05/06/2015] [Indexed: 02/08/2023]
Abstract
Autoimmune hepatitis lacks an identifiable cause, and its diagnosis requires the exclusion of etiologically defined diseases that resemble it. Insights into its pathogenesis are moving autoimmune hepatitis from an idiopathic to explainable disease, and the goal of this review is to describe the insights that are hastening this transition. Two types of autoimmune hepatitis are justified by serological markers, but they also have distinctive genetic associations (DRB1 and DQB1 genes) and autoantigens. DRB1 alleles are the principal susceptibility factors in white adults, and a six amino acid sequence encoded in the antigen-binding groove of class II molecules of the major histocompatibility complex can influence the selection of autoantigens. Polymorphisms, including variants of SH2B3 and CARD10 genes, may affect immune reactivity and disease severity. The cytochrome mono-oxygenase, CYP2D6, is the autoantigen associated with type 2 autoimmune hepatitis, and it shares homologies with multiple viruses that might promote self-intolerance by molecular mimicry. Chemokines, especially CXCL9 and CXCL10, orchestrate the migration of effector cells to sites of injury and are associated with disease severity. Cells of the innate and adaptive immune responses promote tissue damage, and possible deficiencies in the number and function of regulatory T cells may facilitate the injurious process. Receptor-mediated apoptosis is the principal mechanism of hepatocyte loss, and cell-mediated and antibody-dependent mechanisms of cytotoxicity also contribute. Insights that explain autoimmune hepatitis will allow triggering exogenous antigens to be characterized, risk management to be improved, prognostic indices to be refined, and site-specific therapeutic interventions to emerge.
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Affiliation(s)
- Albert J Czaja
- Professor Emeritus of Medicine, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, 200 First Street S.W., Rochester, MN, 55905, USA.
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Liberal R, Vergani D, Mieli-Vergani G. Update on Autoimmune Hepatitis. J Clin Transl Hepatol 2015; 3:42-52. [PMID: 26357634 PMCID: PMC4542083 DOI: 10.14218/jcth.2014.00032] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 12/08/2014] [Accepted: 12/08/2014] [Indexed: 12/17/2022] Open
Abstract
Autoimmune hepatitis (AIH), a liver disorder affecting both children and adults, is characterized by inflammatory liver histology, elevated transaminase levels, circulating nonorganspecific autoantibodies, and increased levels of immunoglobulin G, in the absence of a known etiology. Two types of AIH are recognized according to seropositivity: smooth muscle antibody and/or antinuclear antibody define AIH type 1 and antibodies to liver-kidney microsome type 1 and/or liver cytosol type 1 define AIH type 2. AIH type 1 affects both adults and children, while AIH type 2 is mainly a paediatric disease, though it does occasionally affects young adults. AIH should be considered during the diagnostic workup of any patient with increased liver enzyme levels. AIH is exquisitely responsive to immunosuppressive treatment with prednisolone with or without azathioprine, with symptom free long-term survival for the majority of patients. For those who do not respond to standard treatment, or who are difficult-to-treat, mycophenolate mofetil and, in the absence of a response, calcineurin inhibitors should be tried in addition to steroids. The pathogenesis of AIH is not fully understood, although there is mounting evidence that genetic susceptibility, molecular mimicry and impaired immunoregulatory networks contribute to the initiation and perpetuation of the autoimmune attack. Liver damage is thought to be mediated primarily by CD4 T-cells, although recent studies support the involvement of diverse populations, including Th17 cells. A deeper understanding of the pathogenesis of AIH is likely to contribute to the development of novel treatments, such as the adoptive transfer of autologous expanded antigenspecific regulatory T-cells, which ultimately aim at restoring tolerance to liver-derived antigens.
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Affiliation(s)
- Rodrigo Liberal
- Paediatric Liver, GI & Nutrition Centre and Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, London, UK
| | - Diego Vergani
- Paediatric Liver, GI & Nutrition Centre and Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, London, UK
| | - Giorgina Mieli-Vergani
- Paediatric Liver, GI & Nutrition Centre and Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, London, UK
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Gatselis NK, Zachou K, Koukoulis GK, Dalekos GN. Autoimmune hepatitis, one disease with many faces: Etiopathogenetic, clinico-laboratory and histological characteristics. World J Gastroenterol 2015; 21:60-83. [PMID: 25574080 PMCID: PMC4284362 DOI: 10.3748/wjg.v21.i1.60] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 10/30/2014] [Accepted: 11/19/2014] [Indexed: 02/06/2023] Open
Abstract
Autoimmune hepatitis (AIH) is an unresolving progressive liver disease of unknown etiology characterized by hypergammaglobulinemia, autoantibodies detection and interface hepatitis. Due to the absence of specific diagnostic markers and the large heterogeneity of its clinical, laboratory and histological features, AIH diagnosis may be potentially difficult. Therefore, in this in-depth review we summarize the substantial progress on etiopathogenesis, clinical, serological and histological phenotypes of AIH. AIH has a global distribution affecting any age, both sexes and all ethnic groups. Clinical manifestations vary from asymptomatic to severe or rarely fulminant hepatitis. Hypergammaglobulinemia with selective elevation of IgG is found in most cases. Autoimmune attack is perpetuated, possibly via molecular mimicry, and favored by the impaired control of T-regulatory cells. Histology (interface hepatitis, emperipolesis and hepatic rosette formation) and autoantibodies detection although not pathognomonic, are still the hallmark for a timely diagnosis. AIH remains a major diagnostic challenge. AIH should be considered in every case in the absence of viral, metabolic, genetic and toxic etiology of chronic or acute hepatitis. Laboratory personnel, hepato-pathologists and clinicians need to become more familiar with disease expressions and the interpretation of liver histology and autoimmune serology to derive maximum benefit for the patient.
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Abstract
Apoptosis is the predominant mechanism of liver cell death in autoimmune hepatitis, and interventions that can modulate this activity are emerging. The aim of this review was to describe the apoptotic mechanisms, possible aberrations, and opportunities for intervention in autoimmune hepatitis. Studies cited in PubMed from 1972 to 2014 for autoimmune hepatitis, apoptosis in liver disease, apoptosis mechanisms, and apoptosis treatment were examined. Apoptosis is overactive in autoimmune hepatitis, and the principal pathway of cell death is receptor mediated. Surface death receptors are activated by extrinsic factors including liver-infiltrating cytotoxic T cells and the cytokine milieu. The executioner caspases 3 and 7 cleave nuclear deoxyribonucleic acid, and the release of apoptotic bodies can stimulate inflammatory, immune, and fibrotic responses. Changes in mitochondrial membrane permeability can be initiated by caspase 8, and an intrinsic pathway of apoptosis can complement the extrinsic pathway. Defects in the apoptosis of activated effector cells can prolong their survival and sustain the immune response. Caspase inhibitors have been used in diverse experimental and human diseases to retard apoptosis. Oligonucleotides that inhibit the signaling of toll-like receptors can limit the presentation of auto-antigens, and inhibitors of apoptosis that extend the survival of effector cells can be blocked by antisense oligonucleotides. Mechanisms that enhance the clearance of apoptotic bodies and affect key signaling pathways are also feasible. Interventions that influence the survival of liver and effector cells by altering their apoptosis are candidates for study in autoimmune hepatitis.
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The association between Cytotoxic T lymphocyte associated antigen-4, Fas, tumour necrosis factor-α gene polymorphisms and autoimmune hepatitis: a meta-analysis. Dig Liver Dis 2014; 46:541-8. [PMID: 24629822 DOI: 10.1016/j.dld.2014.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 01/27/2014] [Accepted: 02/06/2014] [Indexed: 12/11/2022]
Abstract
BACKGROUND Several previous studies have assessed the association of Cytotoxic T Lymphocyte Associated Antigen-4, Fas, and Tumour Necrosis Factor-α gene polymorphisms with autoimmune hepatitis risk, but the results were inconsistent and inconclusive. We performed a meta-analysis to better evaluate these associations. METHODS PubMed, EMBASE and MEDLINE were searched in all languages. Overall odd ratios with 95% confidence intervals were calculated to assess the strength of associations using a fixed-effects or random-effects models. RESULTS 15 relevant studies were identified. No significant association was found between CTLA-4+49A/G and AH. TNF-α-308A/G was significantly associated with autoimmune hepatitis risk. Individuals with the "A" allele had a 67% increased risk of autoimmune hepatitis (odds ratio=1.67, 95% confidence interval 1.11-2.52). The genotype "AA" was a potential predisposing factor for autoimmune hepatitis, when compared with the genotype "GG" and "AG+GG" (odds ratio=2.71, 95% confidence interval 1.12-6.57; odds ratio=2.14, 95% confidence interval 1.30-3.52). Besides, no significant association was found between the Fas-670G/A and TNF-α-238A/G polymorphisms and autoimmune hepatitis risk using any model. CONCLUSION The meta-analysis identified the TNF-α-308 "A" allele as a predisposing factor for autoimmune hepatitis, whereas the genotype "GG" was a protective factor. This study did not find a significant association between CTLA-4+49A/G, Fas-670G/A, TNF-α-238A/G and susceptibility to autoimmune hepatitis.
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Samuel B, Fioravanti G, Polimera H, Mayer A, Dorville F, Little E. Autoimmune hepatitis in a 20-year-old African American man. Lab Med 2014; 45:161-71. [PMID: 24868999 DOI: 10.1309/lmag0di6ee4nycyn] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Czaja AJ. Review article: permanent drug withdrawal is desirable and achievable for autoimmune hepatitis. Aliment Pharmacol Ther 2014; 39:1043-58. [PMID: 24628539 DOI: 10.1111/apt.12701] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 02/09/2014] [Accepted: 02/23/2014] [Indexed: 12/12/2022]
Abstract
BACKGROUND Autoimmune hepatitis can be rendered treatment-free, but the difficulty, frequency and risks associated with the pursuit of this outcome are unclear. AIM To describe the frequency that autoimmune hepatitis can be rendered treatment-free, identify the features that characterise these patients, examine the pathogenic pathways that may sustain or terminate the disease and indicate management protocols that can obtain this result. METHODS Studies cited in Pub Med from 1972-2014 for autoimmune hepatitis, treatment, relapse, remission and outcome were selected. RESULTS The frequency of a treatment-free state varies from 19% to 40% in patients observed for ≥3 years after drug withdrawal. Complete laboratory resolution and reversion to normal liver tissue prior to drug withdrawal favours this response. The development of cirrhosis during therapy may increase treatment-dependence. Persistent liver damage and the generation of neo-antigens during the apoptosis of hepatocytes may perpetuate the disease. Genetic and age-related effects on the vigour of the immune response may also contribute. Reversion to normal liver tissue is achieved in only 22% of patients during conventional corticosteroid therapy, and the emerging pharmacological and biological interventions may improve this frequency. A management strategy designed to achieve a treatment-free state accommodates all candidates for this outcome, and it can be modified to a long-term maintenance strategy as warranted by the clinical response. CONCLUSIONS Permanent drug withdrawal is a treatment outcome that is desirable and achievable in patients with autoimmune hepatitis. Normalisation of liver tests and liver tissue during treatment enhances this occurrence.
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Affiliation(s)
- A J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN, USA
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Abstract
Autoimmune hepatitis (AIH) is a chronic inflammatory disease of the liver triggered by an immune-mediated attack, characterized by the presence of hypergammaglobulinemia, serum autoantibodies, interface hepatitis on histological examination, and good response to immunosuppressive therapy. In this article, we will review the role of genetic susceptibility, inducing factors, molecular mimicry, liver injury, and immune regulation imbalance in the pathogenesis of AIH. In addition, this article systematically describes the advances in research of AIH in terms of clinical features, serological characteristics, histologic features, diagnosis and therapy.
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Ngu JH, Wallace MC, Merriman TR, Gearry RB, Stedman CA, Roberts RL. Association of the HLA locus and TNF with type I autoimmune hepatitis susceptibility in New Zealand Caucasians. SPRINGERPLUS 2013; 2:355. [PMID: 23961418 PMCID: PMC3733077 DOI: 10.1186/2193-1801-2-355] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 07/29/2013] [Indexed: 02/06/2023]
Abstract
Purpose The precise etiology of autoimmune hepatitis (AIH) remains unknown, although a number of genetic loci have been implicated in the susceptibility of type 1 AIH. The purpose of this study was to test for association of these loci with type 1 AIH in New Zealand Caucasians. Methods 77 AIH patients and 485 healthy controls were genotyped for the SNPs rs2187668 (HLA-DRB*03:01), rs660895 (HLA-DRB*04:01), rs3749971 (HLA-A1-B8-DR3), rs231775 (CLTLA4), rs1800629 (TNF), and rs1800682 (FAS) using predesigned TaqMan SNP genotyping assays. Chi square analysis was used to test for association of allele and genotype with overall AIH, and with severe fibrosis and ALT levels at 6 months. Results Significant risk of AIH was conferred by the minor alleles of rs2187668 (OR = 2.45, 95% CI 1.65-3.61, p < 0.0001), rs3749971 (OR = 1.89, 95% CI 1.21-2.94, p = 0.004) and rs1800629 (OR = 2.06, 95% CI 1.41-3.01, p = 0.0001). Multivariate analysis showed that rs2187668 was independently associated with type 1 AIH susceptibility (OR = 2.40, 95% CI 1.46-3.93, p = 0.001). The C allele of FAS SNP rs1800682 was associated with increased risk of severe fibrosis at diagnosis (OR = 2.03, 95% CI 1.05-3.93, p = 0.035) and with incomplete normalization of ALT levels at 6 months post-diagnosis (OR = 3.94, 95% CI 1.62-9.54, p = 0.0015). Conclusions This is the first population-based study to investigate genetic risk loci for type 1 AIH in New Zealand Caucasians. We report significant independent association of HLA-DRB1*03:01 with overall susceptibility to type 1 AIH, as well as FAS with a more aggressive disease phenotype.
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Affiliation(s)
- Jing H Ngu
- Department of Medicine, University of Otago, PO Box 434, Christchurch, 8140 New Zealand ; Department of Gastroenterology, Christchurch Hospital, Christchurch, New Zealand
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Ferri Liu PM, de Miranda DM, Fagundes EDT, Ferreira AR, Simões e Silva AC. Autoimmune hepatitis in childhood: the role of genetic and immune factors. World J Gastroenterol 2013; 19:4455-4463. [PMID: 23901220 PMCID: PMC3725369 DOI: 10.3748/wjg.v19.i28.4455] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Revised: 06/05/2013] [Accepted: 06/08/2013] [Indexed: 02/06/2023] Open
Abstract
Autoimmune hepatitis (AIH) is a rare chronic inflammatory disease of the liver, which affects a group of patients who lost their immunological tolerance to antigens of the liver. It is clinically characterized by hypergammaglobulinemia, elevated liver enzymes, presence of autoantibodies and histological changes. Although being rare in children, it represents a serious cause of chronic hepatic disease that can lead to cirrhosis and hepatic failure. Clinical findings, exclusion of more common liver disorders and the detection of antibodies antinuclear antibodies, smooth muscle antibodies and anti-LKM1 are usually enough for diagnosis on clinical practice. The pathogenic mechanisms that lead to AIH remain obscure, but some research findings suggest the participation of immunologic and genetic factors. It is not yet knew the triggering factor or factors that stimulate inflammatory response. Several mechanisms proposed partially explain the immunologic findings of AIH. The knowledge of immune factors evolved might result in better markers of prognosis and response to treatment. In this review, we aim to evaluate the findings of research about genetic and immune markers and their perspectives of application in clinical practice especially in pediatric population.
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Zhang Y, Shan L, Hua Y, Wang D, Zeng H, Liu R, Zhang W, Hu Z. Baicalein selectively induces apoptosis in activated lymphocytes and ameliorates concanavalin a-induced hepatitis in mice. PLoS One 2013; 8:e69592. [PMID: 23894507 PMCID: PMC3718678 DOI: 10.1371/journal.pone.0069592] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 06/10/2013] [Indexed: 12/22/2022] Open
Abstract
Background Insufficient apoptosis in activated lymphocytes contributes to the development of autoimmune hepatitis (AIH). Baicalein (BE), a flavonoid originally isolated from the root of Scutellaria baicalensis Georgi, possesses anti-inflammatory properties. However, whether BE can selectively induce apoptosis in activated lymphocytes and exert therapeutic effect on AIH has not been studied. Methodology/Principal Findings The pro-apoptotic properties of BE were evaluated in vitro on different types of immune cells, and in vivo effects of BE were examined in a murine model of Concanavalin A (Con A)-induced hepatitis. In vitro treatment with BE resulted in a higher increase in the level of apoptosis in Con A-stimulated murine splenocytes, Con A-stimulated CD3+ splenocytes, lipopolysaccharide (LPS)-stimulated CD19+ splenocytes, and phorbol 12-myristate 13-acetate/ionomycin-stimulated Jurkat T cells, compared with that in unstimulated naïve ones. Murine bone marrow-derived dentritic cells, peritoneal macrophages, and RAW264.7 cells, either stimulated with LPS or unstimulated, were all insensitive to the BE-induced apoptosis. BE treatment also led to a loss of mitochondrial membrane potential, an increase of cytochrome c release from mitochondria to the cytosol, a decrease in the ratio of Bcl-2/Bax, and activation of caspase-9,-3 in Con A-stimulated CD3+ splenocytes and LPS-stimulated CD19+ splenocytes, while showing no impact on Fas/FasL expressions and caspase-8 activation. In vivo administration of BE alleviated Con A-induced liver injury, suppressed serum level of TNF-α and IFN-γ, and reduced liver infiltration of mononuclear cells (MNCs). Furthermore, BE treatment increased the incidences of apoptosis in liver-infiltrating MNCs and splenocytes, as well as in CD3+ and CD19+ splenocytes. When liver MNCs and splenocytes from BE-treated mice were cultured in vitro for 24 h, they exhibited marked increase in apoptosis compared to vehicle-treated control. Conclusions/Significance The present study demonstrates the ability of BE to promote apoptosis in activated lymphocytes through mitochondrial pathway and its potential use in the treatment of AIH.
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Affiliation(s)
- Yan Zhang
- School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Lei Shan
- School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Yaping Hua
- School of Pharmacy, Shanghai JiaoTong University, Shanghai, China
| | - Dan Wang
- School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Huawu Zeng
- School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Runhui Liu
- School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Weidong Zhang
- School of Pharmacy, Second Military Medical University, Shanghai, China
- * E-mail: (WZ); (ZH)
| | - Zhenlin Hu
- School of Pharmacy, Second Military Medical University, Shanghai, China
- * E-mail: (WZ); (ZH)
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Czaja AJ. Autoimmune hepatitis in diverse ethnic populations and geographical regions. Expert Rev Gastroenterol Hepatol 2013; 7:365-85. [PMID: 23639095 DOI: 10.1586/egh.13.21] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Autoimmune hepatitis has diverse clinical phenotypes and outcomes in ethnic groups within a country and between countries, and these differences may reflect genetic predispositions, indigenous etiological agents, pharmacogenomic mechanisms and socioeconomic reasons. In the USA, African-American patients have cirrhosis more commonly, treatment failure more frequently and higher mortality than white American patients. Survival is poorest in Asian-American patients. Autoimmune hepatitis in other countries is frequently associated with genetic predispositions that may favor susceptibility to indigenous etiological agents. Cholestatic features influence treatment response; acute-on-chronic liver disease increases mortality and socioeconomic and cultural factors affect prognosis. Ethnic-based deviations from classical phenotypes and the frequency of late-stage disease can complicate the diagnosis and management of autoimmune hepatitis in non-white populations.
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Affiliation(s)
- Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
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Kalkan G, Ateş O, Karakuş N, Sezer S. Functional polymorphisms in cell death pathway genes FAS and FAS ligand and risk of alopecia areata. Arch Dermatol Res 2013; 305:909-15. [PMID: 23591741 DOI: 10.1007/s00403-013-1354-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 03/28/2013] [Accepted: 04/03/2013] [Indexed: 01/13/2023]
Abstract
FAS and FAS ligand (FASLG) are important proapoptotic proteins that have a significant function in regulating cell growth and apoptosis and play essential roles in many human autoimmune diseases. Alopecia areata (AA) is hypothesized to be an organ-specific autoimmune disease mediated by T cells to the hair follicles. The concept of an autoimmune mechanism as the basis for AA led us to investigate a possible association between the FAS and FASLG polymorphism with AA susceptibility and disease progression on AA patients in Turkish population. The study group consisted of 118 unrelated patients with AA and 118 unrelated healthy controls. We genotyped FAS-670 A/G and FASLG-124 A/G polymorphisms and assessed their association with AA risk. A statistically significant difference was observed between patients and controls according to genotype frequencies of FAS gene (p = 0.0002). GG genotype of 670 A/G polymorphism was found to be protective against AA (p = 0.000, OR 0.07, 95 % CI 0.00-0.41). It can be concluded there is a reduced risk of AA risk appeared to be associated with FAS-670 A/G. No association was observed between AA patients and controls according to genotype and allele distribution of FASLG gene 124 A/G polymorphism (p = 0.1297, p = 453, respectively). In conclusion, we provide evidence that FAS/FASLG polymorphisms may have an effect on the risk of AA in the Turkish population. These findings provide an additional support to a genetic basis for AA development.
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Affiliation(s)
- Göknur Kalkan
- Department of Dermatology, Gaziosmanpasa University School of Medicine, Tokat, 60100, Turkey,
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40
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Zamani AG, Barlas IO, Durakbasi-Dursun G, Ural O, Erdal E, Yildirim MS. Evaluation of death pathway genesFASandFASLpolymorphisms in chronic HBV infection. Int J Immunogenet 2013; 40:482-7. [DOI: 10.1111/iji.12056] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 01/07/2013] [Accepted: 03/10/2013] [Indexed: 11/27/2022]
Affiliation(s)
- A. G. Zamani
- Medical Genetics; Meram Medical Faculty; Konya University; Konya Turkey
| | - I. O. Barlas
- Medical Biology and Genetics; Medical Faculty; Mersin University; Mersin Turkey
| | | | - O. Ural
- Infections Diseases and Clinical Microbiology; Selcuklu Medical Faculty; Selcuk University; Konya Turkey
| | - E. Erdal
- Medical Biology and Genetics; Medical Faculty; Mersin University; Mersin Turkey
| | - M. S. Yildirim
- Medical Genetics; Meram Medical Faculty; Konya University; Konya Turkey
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Abstract
Autoimmune hepatitis frequently has an abrupt onset of symptoms, and it can present with acute liver failure. The abrupt presentation can indicate spontaneous exacerbation of a pre-existent chronic disease, newly created disease, a superimposed infectious or toxic injury, or new disease after viral infection, drug therapy, or liver transplantation. Deficiencies in the classical phenotype may include a low serum immunoglobulin G level and low or absent titers of the conventional autoantibodies. The original revised diagnostic scoring system of the International Autoimmune Hepatitis Group can guide the diagnostic evaluation, but low scores do not preclude the diagnosis. Liver tissue examination is valuable to exclude viral-related or drug-induced liver injury and support the diagnosis by demonstrating centrilobular necrosis (usually with interface hepatitis), lymphoplasmacytic infiltration, hepatocyte rosettes, and fibrosis. Conventional therapy with prednisone and azathioprine induces clinical and laboratory improvement in 68-75 % of patients with acute presentations, and high dose prednisone or prednisolone (preferred drug) is effective in 20-100 % of patients with acute severe (fulminant) presentations. Failure to improve or worsening of any clinical or laboratory feature within 2 weeks of treatment or worsening of a mathematical model of end-stage liver disease within 7 days justifies liver transplantation in acute liver failure. Liver transplantation for acute severe (fulminant) autoimmune hepatitis is as successful as liver transplantation for autoimmune hepatitis with a chronic presentation and other types of acute liver failure (patient survival >1 year, 80-94 %). Liver transplantation should not be delayed or superseded by protracted corticosteroid therapy or the empiric institution of nonstandard medications.
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Liberal R, Grant CR, Mieli-Vergani G, Vergani D. Autoimmune hepatitis: A comprehensive review. J Autoimmun 2013; 41:126-39. [DOI: 10.1016/j.jaut.2012.11.002] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Accepted: 11/05/2012] [Indexed: 12/12/2022]
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Czaja AJ. Diagnosis, pathogenesis, and treatment of autoimmune hepatitis after liver transplantation. Dig Dis Sci 2012; 57:2248-66. [PMID: 22562533 DOI: 10.1007/s10620-012-2179-3] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 04/12/2012] [Indexed: 02/06/2023]
Abstract
Autoimmune hepatitis can recur or appear de novo after liver transplantation, and it can result in hepatic fibrosis, graft loss, and re-transplantation. The goals of this review are to describe the prevalence, manifestations, putative pathogenic mechanisms, outcomes, and management of these occurrences. Autoimmune hepatitis recurs in 8-12 % of transplanted patients at 1 year and 36-68 % at 5 years. Recurrence may be asymptomatic and detected only by surveillance liver test abnormalities or protocol liver tissue examination. Autoantibodies that characterized the original disease, hypergammaglobulinemia, increased serum immunoglobulin G level, and histological findings of interface hepatitis, lymphoplasmacytic infiltration, perivenular hepatocyte necrosis, pseudo-rosetting, and acidophil bodies typify recurrence. Premature corticosteroid withdrawal and pre-transplant severity of the original disease are possible risk factors. De novo autoimmune hepatitis occurs in 1-7 % of patients 0.1-9 years after transplantation, especially in children. The appearance of autoantibodies may herald its emergence, and antibodies to glutathione-S-transferase T1 have been predictive of the disease. Recurrent disease may reflect recruitment of residual memory T lymphocytes and host-specific genetic predispositions, whereas de novo disease may reflect an allo-antigenic immune response and molecular mimicries that override self-tolerance. Treatment should be appropriate for autoimmune hepatitis and not based on anti-rejection drugs. Corticosteroid therapy alone or combined with azathioprine is the essential treatment. The substitution of mycophenolate mofetil for azathioprine and switch of the calcineurin inhibitor or its replacement with rapamycin have also been used for refractory disease. Re-transplantation has been necessary in 8-23 %.
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Affiliation(s)
- Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, 200 First Street S.W., Rochester, MN 55905, USA.
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Tang J, Zhou C, Zhang ZJ, Zheng SS. Association of polymorphisms in non-classic MHC genes with susceptibility to autoimmune hepatitis. Hepatobiliary Pancreat Dis Int 2012; 11:125-31. [PMID: 22484578 DOI: 10.1016/s1499-3872(12)60136-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Autoimmune hepatitis is a chronic, generally progressive inflammatory disorder of the liver, of which the cause is unclear. It was demonstrated that genetic factors are involved in its pathogenesis. Previous studies showed that human leukocyte antigen in the major histocompatibility complex (MHC) is associated with susceptibility to autoimmune hepatitis. Current genome scanning studies suggest that genes outside the MHC also play a critical role in autoimmune disorders. This article focuses on our current understanding of the polymorphisms of these genes and their roles in the pathogenesis of autoimmune hepatitis. DATA SOURCES Studies were identified by searching MEDLINE and PubMed for articles using the keywords autoimmune hepatitis, polymorphism, CTLA-4, Fas, TNF-alpha, TGF-beta1, TBX21 and VDR up to May 2011. Additional papers were identified by a manual search of the references from key articles. RESULTS According to the case-control studies on genetic polymorphisms, at least six genes (CTLA-4, Fas, TNF-alpha, TGF-beta1, TBX21 and VDR) are involved in autoimmune hepatitis besides HLA. So far, there has been no agreement about gene susceptibility and the actual clinical significance of these genes is still controversial. CONCLUSION Studies on gene polymorphisms outside the MHC and knowledge of genetic predispositions for autoimmune hepatitis may not only elucidate pathogenic mechanisms, but also provide new targets for therapy in the future.
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Affiliation(s)
- Jie Tang
- Key Laboratory of Combined Multi-organ Transplantation, Ministry of Public Health, Department of Hepatobiliary and Pancreatic Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
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Molin S, Weiss EH, Ruzicka T, Messer G. The FAS/cd95 promoter single-nucleotide polymorphism -670 A/G and lupus erythematosus. Clin Exp Dermatol 2012; 37:425-7. [PMID: 22299671 DOI: 10.1111/j.1365-2230.2011.04296.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
An increased level of circulating nuclear antigens caused by apoptosis is thought to be responsible for the production of autoantibodies in lupus erythematosus (LE). The presentation of these antigens to immunologically competent cells may trigger systemic autoimmunity. The influence of a functional single-nucleotide polymorphism at position -670 in the promoter of the apoptosis gene FAS on susceptibility to autoimmune diseases including systemic LE has been a controversial subject. Although it has not yet been possible to assign any particular allele or genotype to the control of FAS expression, this polymorphism has been described to be associated with several autoimmune diseases including LE. When we compared the FAS -670 A/G genotypes of 107 German patients with LE and those of 96 healthy controls, we found a trend for association between LE and the homozygous A genotype in the patient group. This finding suggests that apoptosis may contribute to development of autoimmune reactions and that FAS function might be relevant for LE.
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Affiliation(s)
- S Molin
- Department of Dermatology and Allergology, Ludwig Maximilian University Munich, Munich, Germany.
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Liberal R, Longhi MS, Mieli-Vergani G, Vergani D. Pathogenesis of autoimmune hepatitis. Best Pract Res Clin Gastroenterol 2011; 25:653-64. [PMID: 22117632 DOI: 10.1016/j.bpg.2011.09.009] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 09/30/2011] [Indexed: 01/31/2023]
Abstract
The mechanisms underlying the pathogenesis of autoimmune hepatitis are not fully understood, though there is growing evidence that genetic predisposition, molecular mimicry and/or impairment of regulatory T-cells are involved in the initiation and perpetuation of the autoimmune liver attack. The histological picture of interface hepatitis, characterized by a dense portal mononuclear cell infiltrate, was the first to suggest an autoaggressive cellular immune attack in the pathogenesis of this condition. Liver damage is likely to be orchestrated by CD4(pos) T-cells recognizing an autoantigenic liver peptide. For autoimmunity to arise, the peptide must be presented by antigen-presenting cells to naïve CD4(pos) T-helper (Th0) cells. Once activated, Th0-cells can differentiate into Th1-, Th2-, or Th17-cells, initiating a cascade of immune reactions that are determined by the cytokines they produce. Autoantigen recognition and the above effector mechanisms are opposed by regulatory T-cells, a cell subset numerically and functionally impaired in autoimmune hepatitis.
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Affiliation(s)
- Rodrigo Liberal
- Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill, London SE5 9RS, UK
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Abstract
The clinical phenotype of classical autoimmune hepatitis can be mimicked by idiosyncratic drug-induced liver injury, and differentiation can be difficult. The goals of this review are to enumerate the major agents of drug-induced autoimmune-like hepatitis, describe the clinical findings and risk factors associated with it, detail the clinical tools by which to assess causality, discuss putative pathogenic mechanisms, and describe treatment and outcome. The frequency of drug-induced autoimmune-like hepatitis among patients with classical features of autoimmune hepatitis is 9%. Minocycline and nitrofurantoin are implicated in 90% of cases. Female predominance, acute onset, and absence of cirrhosis at presentation are important clinical manifestations. Genetic factors affecting phase I and phase II transformations of the drug, polymorphisms that protect against cellular oxidative stress, and human leukocyte antigens that modulate the immune response may be important pathogenic components. Clinical judgment is the mainstay of diagnosis as structured diagnostic methods for drug-induced liver injury are imperfect. The covalent binding of a reactive drug metabolite to a hepatocyte surface protein (commonly a phase I or phase II enzyme), formation of a neoantigen, activation of CD8 T lymphocytes with nonselective antigen receptors, and deficient immune regulatory mechanisms are the main bases for a transient loss of self-tolerance. Discontinuation of the offending drug is the essential treatment. Spontaneous improvement usually ensues within 1 month. Corticosteroid therapy is warranted for symptomatic severe disease, and it is almost invariably effective. Relapse after corticosteroid withdrawal probably does not occur, and its absence distinguishes drug-induced disease from classical autoimmune hepatitis.
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Genetic background of autoimmune hepatitis in Japan. J Gastroenterol 2011; 46 Suppl 1:42-7. [PMID: 20957499 DOI: 10.1007/s00535-010-0333-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Accepted: 09/15/2010] [Indexed: 02/04/2023]
Abstract
Autoimmune hepatitis (AIH) is an organ-specific autoimmune disease characterized by chronic inflammation of the liver. Several studies from ethnically different countries have clarified that the genetic predisposition to type 1 AIH is linked mainly to human leukocyte antigen (HLA)-class II genes. Recently, molecular analysis using polymerase chain reaction (PCR)-based DNA typing has revealed that susceptibility to type 1 AIH is primarily associated with the HLA class II DRB1 locus, which encodes a polymorphic β chain of the HLA-DR antigen. However, additional susceptibility genes (either HLA or non-HLA) and/or environmental factors may also contribute to the development of type 1 AIH; in Japanese type 1 AIH patients, although the most influential gene in disease susceptibility is HLA-DRB1*04:05, several other genes have been identified as being involved in AIH pathogenesis or resistance and are the currently the focus of single nucleotide polymorphism analysis.
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Czaja AJ. Emerging opportunities for site-specific molecular and cellular interventions in autoimmune hepatitis. Dig Dis Sci 2010; 55:2712-26. [PMID: 20108036 DOI: 10.1007/s10620-009-1122-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2009] [Accepted: 12/28/2009] [Indexed: 02/08/2023]
Abstract
Current corticosteroid-based treatments of autoimmune hepatitis frequently have incomplete or unsatisfactory outcomes, side effects, and excessive immune suppression. The goal of this review is to describe the advances in developing animal models of autoimmune hepatitis and in treating diverse immune-mediated diseases that make pursuit of site-specific molecular and cellular inventions in autoimmune hepatitis feasible. Prime source and review articles in English were selected by a Medline search through October 2009. A murine model infected with an adenovirus expressing human CYP2D6 is a resource for evaluating new therapies because of its histological and serological features, persistence, and progressive hepatic fibrosis. Synthetic analog peptides that block autoantigen expression, a dimeric recombinant human fusion protein of cytotoxic T lymphocyte antigen-4, monoclonal antibodies against tumor necrosis factor-alpha, recombinant interleukin 10, tolerization techniques for disease-triggering autoantigens, T regulatory cell transfer, vaccination against antigen-specific cytotoxic CD8+ T cells, and gene silencing methods using small inhibitory RNAs are feasible interventions to explore. Treatments directed at dampening immunocyte activation with soluble cytotoxic T lymphocyte antigen-4, inhibiting immunocyte differentiation with recombinant interleukin 10, and improving immunosuppressive activity with regulatory T cell modulation have the most immediate promise. Progress in the development of an animal model of autoimmune hepatitis and experiences in other immune-mediated diseases justify the evaluation of site-specific molecular and cellular interventions in this disease.
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Affiliation(s)
- Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
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Czaja AJ, Manns MP. Advances in the diagnosis, pathogenesis, and management of autoimmune hepatitis. Gastroenterology 2010; 139:58-72.e4. [PMID: 20451521 DOI: 10.1053/j.gastro.2010.04.053] [Citation(s) in RCA: 194] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2010] [Revised: 04/27/2010] [Accepted: 04/30/2010] [Indexed: 12/13/2022]
Abstract
Autoimmune hepatitis (AIH) is characterized by chronic inflammation of the liver, interface hepatitis (based on histologic examination), hypergammaglobulinemia, and production of autoantibodies. Many clinical and basic science studies have provided important insights into the pathogenesis and treatment of AIH. Transgenic mice that express human antigens and develop autoantibodies, liver-infiltrating CD4(+) T cells, liver inflammation, and fibrosis have been developed as models of AIH. AIH has been associated with autoantibodies against members of the cytochrome P450 superfamily of enzymes, transfer RNA selenocysteine synthase, formiminotransferase cyclodeaminase, and the uridine diphosphate glucuronosyltransferases, whereas alleles such as DRB1*0301 and DRB1*0401 are genetic risk factors in white North American and northern European populations. Deficiencies in the number and function of CD4(+)CD25(+) (regulatory) T cells disrupt immune homeostasis and might be corrected as a therapeutic strategy. Treatment can be improved by continuing corticosteroid therapy until normal liver test results and normal liver tissue are within normal limits, instituting ancillary therapies to prevent drug-related side effects, identifying problematic patients early, and providing long-term maintenance therapy after patients experience a first relapse. Calcineurin inhibitors and mycophenolate mofetil are potential salvage therapies, and reagents such as recombinant interleukin-10, abatacept, and CD3-specific antibodies are feasible as therapeutics. Liver transplantation is an effective salvage therapy, even in the elderly, and AIH must be considered in all patients with graft dysfunction after liver transplantation. Identification of the key defects in immune homeostasis and antigen targets will direct new therapies.
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Affiliation(s)
- Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
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