Autoimmune enteropathy (AIE) is a rare disease whose diagnosis and long-term prognosis remain challenging, especially for adult AIE patients.

To improve overall understanding of this disease's diagnosis and prognosis.

We retrospectively analyzed the clinical, endoscopic and histopathological characteristics and prognoses of 16 adult AIE patients in our tertiary medical center between 2011 and 2023, whose diagnosis was based on the 2007 diagnostic criteria.

Diarrhea in AIE patients was characterized by secretory diarrhea. The common endoscopic manifestations were edema, villous blunting and mucosal hyperemia in the duodenum and ileum. Villous blunting (100%), deep crypt lymphocytic infiltration (67%), apoptotic bodies (50%), and mild intraepithelial lymphocytosis (69%) were observed in the duodenal biopsies. Moreover, there were other remarkable abnormalities, including reduced or absent goblet cells (duodenum 94%, ileum 62%), reduced or absent Paneth cells (duodenum 94%, ileum 69%) and neutrophil infiltration (duodenum 100%, ileum 69%). Our patients also fulfilled the 2018 diagnostic criteria but did not match the 2022 diagnostic criteria due to undetectable anti-enterocyte antibodies. All patients received glucocorticoid therapy as the initial medication, of which 14/16 patients achieved a clinical response in 5 (IQR: 3-20) days. Immunosuppressants were administered to 9 patients with indications of steroid dependence (6/9), steroid refractory status (2/9), or intensified maintenance medication (1/9). During the median of 20.5 months of follow-up, 2 patients died from multiple organ failure, and 1 was diagnosed with non-Hodgkin's lymphoma. The cumulative relapse-free survival rates were 62.5%, 55.6% and 37.0% at 6 months, 12 months and 48 months, respectively.

Certain histopathological findings, including a decrease or disappearance of goblet and Paneth cells in intestinal biopsies, might be potential diagnostic criteria for adult AIE. The long-term prognosis is still unsatisfactory despite corticosteroid and immunosuppressant medications, which highlights the need for early diagnosis and novel medications.

Autoimmune enteropathy (AIE) defined by intractable diarrhoea and nonceliac enteropathy with villous atrophy, is a rare digestive disease. Case reports of this disease are sporadic and the clinical characteristics of AIE is seldom discussed.

We evaluate the clinical, laboratory, histopathological features, response to therapy and outcome of AIE in children.

We conducted a retrospective analysis of five children with AIE in our hospital. A comprehensive search of MEDLINE was performed using PubMed, through keywords of "autoimmune enteropathy, pediatric or children". The clinical manifestations, endoscopic results, pathological results, and medication therapy of these children were collected and the cases were divided into two groups, infants (≤ 1 year old) and children (> 1 year old).

Five cases treated in our department: one case took eight years to make the final diagnosis; one case was positive for anti-intestinal epithelial cell (AE) antibody; three cases showed crypt apoptosis in histopathology; and two cases showed celiac-like changes. All cases were responsive to glucocorticoid therapy in the early stage of treatment, while three cases required immunosuppressant maintenance. After reviewing the literature, we performed a statistical analysis of 50 cases with a male-to-female ratio of 31:19. Among them, 35 patients (70%) were within 1 year of age, and their clinical manifestations were mainly watery stool (43 cases, 86%), weight loss (28 cases, 56%), abdominal distension (3 cases, 6%), serum AE or anti-goblet cell (AG) antibody positivity (32 cases, 64%), other immune-related antibodies (21 cases, 42%), gene mutations (9 cases, 18%), and family history (21 cases, 42%). All the children showed different degrees of intestinal villous atrophy. Thirty-seven (74%) of the children were treated early, and their clinical symptoms were relieved. Comparing the cases between different age groups, it was found that the mortality rate of children with onset in infancy was higher (P < 0.05), and there was no difference in other autoimmune diseases, AE antibody positivity rates, and other antibodies between the two groups. In addition to survival rate between different age group (P = 0. 005), there was no difference in sex, autoantibody positivity rate, single gene mutation, or family history between the two groups (P > 0.05) through analysis of mortality and clinical remission cases.

Endoscopic examination and mucosal pathological examination should be performed to diagnose AIE in children with watery stool and weight loss who fail to be treated with diet therapy. Immunotherapy is the core of medical management of AIE and can improve prognosis. Children with a poor prognosis in infancy should be actively treated to reduce mortality rates associated with AIE.

Adult-onset autoimmune enteropathy (AIE) is a rare cause of severe chronic diarrhea because of small intestinal villous atrophy. We report on patients with adult-onset AIE in an European referral center.

Retrospective study including patients diagnosed with AIE in the Amsterdam UMC, location VUmc, between January 2003 and December 2019. Clinical, serological, and histological features and response to treatment were reported. The specificity of antienterocyte antibodies (AEA) was evaluated by examining the prevalence of AEA in (i) controls (n = 30) and in patients with (ii) AIE (n = 13), (iii) celiac disease (CD, n = 52), (iv) refractory celiac disease type 2 (n = 18), and (v) enteropathy-associated T-cell lymphoma (EATL, n = 10).

Thirteen AIE patients were included, 8 women (62%), median age of 52 years (range 23-73), and 6 (46%) with an autoimmune disease. AEA were observed in 11 cases (85%), but were also found in CD (7.7%), refractory celiac disease type 2 (16.7%), and EATL (20%). Ten patients (77%) were human leukocyte antigen DQ2.5 heterozygous. Total parenteral nutrition was required in 8 cases (62%). Steroids induced clinical remission in 8 cases (62%). Step-up therapy with rituximab, cyclosporine, infliximab, and cladribine in steroid-refractory patients was only moderately effective. Four patients died (31%), but 4 (31%) others are in long-term drug-free remission after receiving immunosuppressive treatment, including 1 patient who underwent autologous stem cell transplantation.

Adult-onset AIE is a rare but severe enteropathy that occurs in patients susceptible for autoimmune disease. Four patients (31%) died secondary to therapy-refractory malabsorption, while immunosuppressive therapy leads to a long-lasting drug-free remission in one-third of patients.

Chronic diarrhea, villous atrophy and/or increased intraepithelial T-lymphocytes (IEL) occur in many inflammatory disorders including celiac disease (CD). However, a definite diagnosis is difficult to make in some patients despite an extensive diagnostic work-up. Clinical outcomes and histological phenotypes of such patients we refer to as unclassifiable enteropathy (UEP) remain unclear.

We performed a retrospective single-center analysis of patients with chronic diarrhea, weight loss and increased IEL. Patients with defined etiologies including infections, CD, drugs, immunodeficiencies or neoplasms were excluded. Clinical and histologic/immunophenotypic parameters were analyzed.

Nine patients with UEP were identified. Small intestinal damage ranged from minor villous abnormalities to complete atrophy while all patients displayed high numbers of CD103+ CD8+ IELs. In contrast to CD, these CD8+ T cells were not confined to the surface epithelium, but also infiltrated the crypts. Additional histological features included apoptotic crypt epithelial cells and mixed inflammatory infiltrates in the tunica propria. Involvement of other segments of the gastrointestinal tract was observed in 7/9 patients. A clonal intestinal T-cell lymphoproliferative disorder developed in 2 patients, one of which had a fatal disease course. The majority of patients responded to corticosteroids, while response to immunosuppressive medications yielded heterogeneous results.

We report a patient population with 'difficult-to-classify' enteropathies characterized by various degrees of villous atrophy and strongly increased intraepithelial CD103+ CD8+ T cells in the small intestine which harbor an increased risk for T-cell lymphoproliferative disorders. Clinical course, histology, and response to immunosuppressive therapy all suggest an autoimmune pathogenesis.

Autoimmune enteropathy (AIE) is a rare immune disorder of the gut seldom found in adults and characterized by uncontrollable diarrhea resulting in malabsorption. While AIE is known to be pan-enteric, virtually all cases have presented with altered duodenal histology following known patterns with or without macroscopic change. We describe a unique case of seronegative AIE lacking typical duodenal manifestations in a 43-year-old female. To our knowledge, this is the first report of AIE lacking usual duodenal histologic changes, which resulted in missed diagnosis for years. Ultimately, crypt epithelial apoptosis, mononuclear inflammation of the lamina propria, and goblet cell loss of intestinal mucosa besides the duodenum clinched the diagnosis of AIE. Colonic histologic abnormalities consistent with AIE in the setting of diarrhea with malnutrition despite duodenal sparing should prompt suspicion for AIE given the pan-enteric nature of this disease.

Autoimmune enteropathy (AIE) is a complex disease affecting both children and adults. Although associated with significant morbidity and mortality, the pathophysiology of the disease and its treatment have not been well characterized. This study aims to review the medical literature available on this rare but clinically significant ailment, to help establish a better understanding of its pathophysiology and enumerate the available diagnostic and treatment modalities. A literature search was conducted on PubMed using key terms related to autoimmune enteropathy and intractable diarrhea, with no restrictions on the date of publication or language. We found a total of 98 reports of AIE published in the form of case reports and case series. The evidence reviewed suggests that AIE is a multifaceted disorder that requires a high index of suspicion in the appropriate clinical setting to be able to make an early diagnosis. Current evidence supports the use of supportive care to correct nutritional and metabolic deficiencies, and immunosuppressives and immunomodulators as directed therapies. Hematopoietic stem cell transplant is an aggressive, but successful curative modality for patients with AIE as part of immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome. Cumulative clinical experience with management of AIE has allowed improved outcomes in transplanted and non-transplanted AIE patients even though morbidity and mortality with are still high in patients with this condition. More research is needed to further define the role of new therapies for AIE, and a central registry with participation of multiple institutions might help share and standardize care of patients with this rare but serious condition.

Autoimmune enteropathy (AIE) is a rare disorder characterized by severe diarrhea and small intestinal mucosal atrophy resulting from immune-mediated injury. It remains a challenging diagnosis because of its clinicopathologic variability. To better understand its histopathologic features, we describe the gastrointestinal biopsy findings of 25 patients, including children and adults. The most common finding on small intestinal biopsy (13/25 cases, 52%) was villous blunting, expansion of the lamina propria by mixed but predominantly mononuclear inflammation, and neutrophilic cryptitis with or without crypt microabscesses. In 5 cases (20%), the duodenum exhibited changes indistinguishable from celiac disease, with villous blunting and intraepithelial lymphocytosis. Increased crypt apoptosis with minimal inflammation, resembling acute graft-versus-host disease, was observed in 4 cases (16%). The remaining 3 cases (12%) exhibited a mixture of 2 or more of the above patterns. Mucosal abnormalities outside the small intestine were present in all 24 cases with available biopsies (100%), with the stomach most commonly affected (19/22 cases, 86%), followed by the colon (14/22, 64%) and esophagus (5/18, 28%). Findings in non-small intestinal sites were variable and included mixed active and chronic inflammation, chronic inflammation alone, intraepithelial lymphocytosis, and increased apoptosis resembling acute graft-versus-host disease. In summary, AIE most commonly presents as an active enteritis with villous blunting and expansion of the lamina propria by mixed inflammation. Mucosal abnormalities are frequently seen elsewhere in the gut. AIE may thus be better regarded as a pan-gastrointestinal autoimmune disorder, and biopsies from sites other than the small intestine may greatly facilitate its diagnosis.

The term pediatric autoimmune enteropathy was originally applied to a form of intractable diarrhea seen in children under the age of 6 months and characterized by male predominance, concurrent autoimmune-associated disorders, circulating gut autoantibodies, a lack of severe immunodeficiency and small bowel atrophy with prominent crypt apoptosis. However, recent studies have cast doubt over the specific clinicopathologic findings associated with this entity. We, therefore, collected 178 gastrointestinal biopsies from 14 patients and examined their clinical, serologic and pathologic findings. Patients at presentation ranged in age from birth to 15.9 years (median, 5.5 months; mean, 4.1 years) and included six males and eight females. All children suffered from chronic watery diarrhea and malnutrition. Concomitant-associated disorders were noted in 11 (79%) cases and included 10 (71%) with an immunodeficiency disorder and/or another autoimmune-related disease. Eleven patients (79%) were positive for anti-enterocyte antibodies. The salient findings of autoimmune enteropathy were most prominent in the small intestines and the majority (79%) of patients demonstrated villous blunting, crypt hyperplasia, mononuclear cell inflammatory expansion of the lamina propria and crypt apoptosis. The remaining (21%) patients showed marked intraepithelial lymphocytosis reminiscent of celiac disease. Further, acute cryptitis and crypt abscesses were seen in seven (50%) patients obscuring the presence of apoptosis. The absence of Paneth cells, goblet cells or both was noted in seven (50%) patients. Follow-up information was available for all patients with 13 (93%) receiving immunosuppressant therapy and demonstrating partial-to-complete response. In total, three patients died from continued diarrhea and sepsis with one decedent before treatment could be initiated. In summary, autoimmune enteropathy in children is a heterogenous disease with protean clinical and pathologic findings. Although anti-enterocyte antibodies were identified in the majority of the cases, their presence was variable and insensitive. In addition, pediatric autoimmune enteropathy was frequently encountered in the setting of immunodeficiency disorders.

In the clinical context of pediatric diarrheal illness, the interpretation of endoscopic mucosal biopsies varies significantly from that in adults. This review outlines these differences by first describing a host of diarrheal illnesses that are nearly exclusive to the pediatric age group. The final portion of this article describes salient pathologic differences between adult and pediatric idiopathic inflammatory bowel disease. The goal of this review is to provide a brief description of each disease process and focus on practical aspects of diagnosis that are applicable for pathologists working in general practice settings.

Autoimmune enteropathy (AIE) is a rare condition characterized by intractable diarrhea, histologic changes on small intestinal biopsy, and failed response to dietary manipulation that also may present with extraintestinal manifestations. In many patients, immunosuppressive therapies are necessary. Although AIE is more common in infants, adult involvement has also been documented. Much of what is known about AIE has been gathered from case reports and small case series; therefore, more research in this evolving field is needed. IPEX (immunodysregulation polyendocrinopathy enteropathy X-linked syndrome) and APECED (autoimmune phenomena, polyendocrinopathy, candidiasis, and ectodermal dystrophy) are systemic forms of AIE.

Autoimmune enteropathy (AIE) is a rare condition characterized by intractable diarrhea, histologic changes on small intestinal biopsy, and failed response to dietary manipulation that also may present with extraintestinal manifestations. In many patients, immunosuppressive therapies are necessary. Although AIE is more common in infants, adult involvement has also been documented. Much of what is known about AIE has been gathered from case reports and small case series; therefore, more research in this evolving field is needed. IPEX (immunodysregulation polyendocrinopathy enteropathy X-linked syndrome) and APECED (autoimmune phenomena, polyendocrinopathy, candidiasis, and ectodermal dystrophy) are systemic forms of AIE.

Autoimmune enteropathy is a rare disorder characterized by severe and protracted diarrhea, weight loss from malabsorption and immune-mediated damage to the intestinal mucosa, generally occurring in infants and young children, although some cases of adult onset have been reported in the literature. Pathogenetic mechanisms involve immunological disorders, in which the presence of antienterocyte autoantibodies, although detected since first description, seems now to be secondary. As occurs frequently in autoimmunity, subjects with autoimmune enteropathy may be affected by other autoimmune disorders, sometimes leading to particular forms, i.e. the IPEX syndrome and the APECED syndrome. The prognosis of autoimmune enteropathy patients depends on the severity of digestive symptoms (including fecal output), on the severity and extension of histological lesions along the gastrointestinal apparatus, and on the presence of extra-intestinal involvement. Management of autoimmune enteropathy patients is based on nutritional support and adequate hydration to ensure optimal growth and development, together with immunosuppressive therapy. Recently, biological agents have been introduced, with apparent beneficial effects.

Protracted diarrhea is used to describe infants with loose and frequent stools of sufficient severity to require nutritional support, most commonly parenteral nutrition. Despite similar clinical presentations, the causes of protracted diarrhea in infants are varied and diverse in management and prognosis. The following cases represent the two more common causes of protracted diarrhea in young infants in the developed world - allergic and autoimmune enteropathy. Both patients demonstrate diagnostic challenges related to clinical and/or laboratory features. These cases illustrate the important role histological assessment plays in determining the correct diagnosis, treatment course and prognosis in infants with protracted diarrhea.

The expression of adhesion molecules by cells of the small intestinal mucosa was compared in gut biopsies from children with autoimmune small intestinal enteropathy and normal controls and related to HLA-DR expression by the same tissue. Jejunal biopsies were stained by IFL with monoclonal antibodies to LFA-1 (TS1/22 and CD11a/25.3.1) and ICAM-1 (RR1/1 and 84H10) molecules. LFA-1 and ICAM-1 positive cells were observed in the lamina propria in all cases and the counts were increased in autoimmune enteropathy compared with controls. In addition, in 4 of 7 cases of autoimmune enteropathy crypt enterocytes were positives for ICAM-1 when stained with RR1/1 and 3 of the 4 were also positive for LFA-1 when stained with both LFA-1 reagents. We speculate on the role of adhesion molecule expression in autoimmune enteropathy.

The term autoimmune enteropathy (AIE) was applied to a form of "intractable diarrhoea" with serum gut autoantibodies, characterized by male predominance, early onset, poor response to parenteral nutrition and several autoimmune diseases, mainly type 1 diabetes. In recent years the vague concept of AIE has became more precise thanks to the discovery of its genetic and molecular basis. The FOXP3 molecule is crucial for the generation and maturation of regulatory T cells (Treg) expressing CD4+ and CD25+ molecules. Mutations of the FOXP3 gene, located in X chromosome, produce a syndrome with Immune dysfunction, Polyendocrinopathy, Enteropathy and X-linked inheritance (IPEX). The majority of the ancient so-called AIE cases probably correspond to the new IPEX syndrome, even in female patients who may have some autosomal genetic variants. Besides FOXP3, other molecules are likely to be involved in the generation and function of Treg and its deficiency may also enhance autoimmune disease and IPEX-like syndromes. Meanwhile, the important pathogenic role previously ascribed to gut autoantibodies has vanished, with it remaining as having only certain screening usefulness.

The significance of colonic intraepithelial lymphocytosis has been well described in adults, and is associated with lymphocytic colitis, untreated celiac disease, and medications, among others. Little is known about the meaning of colonic intraepithelial lymphocytosis in the pediatric population; this study examines this finding in a cohort of children. Twenty patients in whom colonic intraepithelial lymphocytosis was a prominent feature were identified from 1999 to 2005. Colonic intraepithelial lymphocytosis was defined as 20 or more intraepithelial lymphocytes per 100 colonocytes present in at least one colonic mucosal biopsy. Each biopsy was examined for numbers of intraepithelial lymphocytes per 100 surface and crypt colonocytes; various architectural, inflammatory, and metaplastic changes were also noted. When available, concurrent duodenal and/or ileal biopsies were examined. Studied clinical parameters included indications for biopsy, clinical follow-up, final diagnosis, comorbidities, autoimmune serologies, and medications. A total of 121 colonic mucosal biopsies were examined in 20 patients who ranged from 1 to 17 years (mean 10.2 years; 40% male). Common indications for endoscopy included diarrhea and abdominal pain. A mean of 29 (+/-22) intraepithelial lymphocytes per 100 enterocytes were seen. Seven patients had colonic intraepithelial lymphocytosis as the only histologic finding. The remaining 13 patients had additional architectural, inflammatory, and metaplastic changes. The mean follow-up period was 14 months (range 1-48 months). Inflammatory bowel disease was diagnosed in 4 of 20 patients and was seen chiefly in biopsies in which colonic intraepithelial lymphocytosis was associated with architectural or inflammatory changes. Common disease associations include celiac disease, lymphocytic colitis, and autoimmune enteropathy. Pediatric colonic intraepithelial lymphocytosis, in the absence of other histologic findings, is associated with various diseases, including celiac disease, lymphocytic colitis, and autoimmune enteropathy. Colonic intraepithelial lymphocytosis in the presence of other inflammatory changes indicates the possibility of idiopathic inflammatory bowel disease. These findings are similar to those seen in adults, with the exception of autoimmune enteropathy.

To investigate the incidence, prevalence and the long-term outcome of autoimmune enteropathy in Sweden.

In 2002 a questionnaire was sent to all paediatric departments in Sweden asking them to report all known cases of this condition from the period 1985-2002.

The response rate was 92%. Five patients were reported and 3 were included in the study. Only one patient fulfilled all the diagnostic criteria and two were considered as possible cases of autoimmune enteropathy. The incidence was 0.06 to 0.12 x 10(-5) and the prevalence was 0.05 to 0.10 x 10(-5) for children aged 0-16 years. At the end of the study period all 3 patients were still alive. Two boys were receiving immunosuppressive treatment and one girl was in remission and functioning well on a gluten-free diet only. One of the patients had adrenalitis. This combination has not been reported previously in autoimmune enteropathy.

Autoimmune enteropathy in its severe forms is a rare disease in Sweden. None of the patients reported died during the study period. Comparative studies are difficult as different diagnostic criteria are used to diagnose this disease.

This review focuses on the autoimmune connective tissue diseases, endocrine, and dermatologic conditions associated with celiac disease, as well as the related gut inflammatory disorders of refractory celiac disease, autoimmune enteropathy, collagenous enteritis, and collagenous colitis.

Autoimmune enteropathy is a rare cause of intractable diarrhea associated with circulating gut autoantibodies and a predisposition to autoimmunity. It is rarely observed in adults, with only 11 cases reported to date.

Fifteen adults with autoimmune enteropathy were identified at the Mayo Clinic, Rochester, from May 2001-June 2006. The demographic, clinical, and treatment data were abstracted from their records.

The study population was 87% white, 47% female, with median age of 55 years (interquartile range, 42-67 years). All patients had protracted diarrhea, weight loss, and malnutrition. Celiac disease was excluded by lack of response to gluten-free diet or absence of the celiac disease susceptibility HLA genotypes. Fourteen patients were tested for gut epithelial cell antibodies, and 93% were positive for anti-enterocyte and/or anti-goblet cell antibodies. Predisposition to autoimmune diseases was noted in 80%, as indicated by a variety of circulating autoantibodies. Small intestinal histopathologic findings included subtotal villous atrophy and lymphoplasmacytic infiltration in the lamina propria with relatively few surface intraepithelial lymphocytes. T-cell receptor gene rearrangement studies were negative in all cases. Immunosuppressive therapy was required in 93% of cases. Clinical improvement was noted in 60% after 1-8 weeks of steroid therapy.

Autoimmune enteropathy is a heterogeneous disease and should be considered in the differential diagnosis of malabsorption and small bowel villous atrophy. The presence of gut epithelial cell antibodies can help confirm the diagnosis. No single agent is unequivocally effective in inducing remission, and immunosuppressive therapy is required in most cases.

Recent studies on gluten sensitive enteropathy (GSE) have heightened the pathologist's awareness of intraepithelial lymphocytes in duodenal biopsies. Mild histologic forms of GSE are now recognized with increased IELs as the only histologic change. In this review, both the classic morphology and "minimal deviation" GSE are discussed in detail, with special emphasis on the differential diagnosis and how to avoid overdiagnosing this condition. The Marsh-Oberhuber classification is described and contrasted with a more practical diagnostic terminology that is recommended for use in pathology reports. Other important conditions associated with duodenal lymphocytosis, such as refractory sprue, autoimmune enteropathy, and Helicobacter pylori-associated duodenitis, are also presented.

Autoimmune enteropathy is a rare disorder of unknown pathogenesis, characterized by protracted diarrhea, villous atrophy, and enterocyte autoantibodies. Its association with extended inflammation of the whole gastrointestinal tract is termed as generalized autoimmune gut disorder (GAGD), generally a pediatric disease of difficult management due to its association with immunodeficiency. The aim of our work is to describe the mucosal immunological basis of an adult-onset case of GAGD.

We studied an adult female with a severe inflammatory involvement of the gastrointestinal tract (stomach, small and large bowel, and liver) and antienterocyte autoantibodies. She had antibody deficiency and a predisposition to systemic autoimmunity. We analyzed, by immunohistochemistry and flow cytometry, the phenotypic and functional characteristics of her intestinal intraepithelial and lamina propria (LP) lymphocytes.

We observed the prominent and constant presence of an unusual CD4+alphaE/beta7- Tc subset in the jejunal epithelium. Signs of the lymphocyte activation as well as the prominent lymphoid TNF-alpha production observed in the rectal mucosa support the involvement of a cell-mediated pro-inflammatory response in the pathogenesis of GAGD.

We report the second case of an adult fulfilling all diagnostic criteria for GAGD. We propose that the activated LP CD4+ T lymphocytes, as well as those atypically located in the epithelium, may play a pathogenic role. The alphaE/beta7- IEL could constitute a diagnostic marker of intestinal autoimmunity in the cases when autoantibodies are not evidenced, and mucosal TNF-alpha might represent a novel therapeutic target in this severe disease.

The presence of circulating autoantibodies to gut enterocytes has been very rarely described in adults and is considered a possible cause of refractory sprue. Our aims was to describe the case of an adult patient with serum anti-enterocyte autoantibodies associated with a clinical picture characterized by involvement of both the small intestine and colon. A female, age 50, had suffered from diarrhea with mucus and blood, abdominal pain, thinness, anemia, and leukopenia since the age of 20. She also suffered from HCV infection and had mild chronic hepatitis. Family history was positive for autoimmunity. Symptoms were reported to worsen after eating gluten-containing foods, but anti-transglutaminase and anti-endomysial antibodies were negative. Intestinal histology showed mild, patch villous atrophy with a high intraepithelial lymphocyte count, but a normal number of intraepithelial lymphocytes carrying the gamma/delta+ receptor. HLA was: A11, A31 (19), B52 (5), DR 15 (2), DR 14 (6), DR 51, DR 52, DQ1. Colonoscopy did not show ulcerations or erosions and colon histology showed a moderate inflammatory infiltrate without minor crypt distortion or granuloma. RAST tests were positive for lactalbumin, lactoglobulin, casein, egg, and gliadin. After commencement of an oligoantigenic diet, stool frequency initially decreased, but the presence of mucus in the stools persisted, with episodes of bloody diarrhea. After one year of diet, nutritional parameters were low and anemia associated with a low leukocyte count persisted. Upper and lower gastrointestinal endoscopy and histology of the small intestine and colon were virtually unchanged. Consequently, natural autoantibodies and enterocyte autoantibodies were assayed. The patient was positive for IgG class enterocyte autoantibodies at a titer of 1:34. No other organ-specific or non-organ-specific autoantibodies were positive. Prednisolone treatment was started and the symptoms improved. After one year of this treatment plus elimination diet she was reevaluated. Bowel movement frequency was normal, body weight increased, and the asthenia had completely regressed. IgG anti-enterocyte autoantibodies were absent. Histology of the distal duodenum showed a normal villus/crypt ratio and IEL infiltration was reduced. Colon histology showed a reduction in inflammatory infiltrate in the lamina propria. In conclusion, we report a case of generalized gut disorder in an adult patient, affecting both the small intestine and the colon and characterized by the presence of circulating anti-enterocyte autoantibodies. Systematic testing for enterocyte autoantibodies should be performed not only in patients with refractory sprue, but also in subjects with upper and lower intestinal symptoms who have not been definitively diagnosed.

Celiac disease is a gluten-sensitive enteropathy, characterized by villous atrophy, which is reversed by gluten withdrawal. A minority of patients with celiac-like enteropathy are resistant to gluten-free diet, so-called refractory sprue, or unclassified sprue. Refractory sprue is a diagnosis of exclusion; all other causes of a celiac-like enteropathy must be eliminated before a diagnosis of refractory sprue can be made. Recent evidence suggests that refractory sprue comprises a heterogenous group of patients with diverse underlying causes. A small proportion of these patients seem to have an adult form of autoimmune enteropathy, characterized by the presence of antienterocyte antibodies. However, a larger group of patients with refractory sprue now seem to have a cryptic intestinal T-cell lymphoma, characterized by the presence of phenotypically abnormal, monoclonal intraepithelial lymphocytes, despite benign cytology. Current therapeutic options include nutritional support and immunosuppressive therapy, but response is variable. The prognosis of refractory sprue may be poor; patients may die of severe malabsorption, or through synchronous or metachronous development of an enteropathy-associated T-cell lymphoma. Based on this recent evidence, patients with refractory sprue should be screened for antienterocyte antibodies and have T-cell receptor and monoclonal antibody studies performed; this could facilitate identification of cases of adult-onset autoimmune enteropathy and those of cryptic T-cell lymphoma. Moreover, early recognition of the malignant nature of the intestinal infiltrate in some cases of refractory sprue could permit the development of novel chemotherapeutic regimens for this condition.

Allogenic transfusion of immunocompetent T lymphocytes into an immunodeficient recipient is necessary for the development of graft-versus-host-disease (GVHD). The gastrointestinal tract is one of the most involved organs in human GVHD, and single-cell necrosis with apoptotic change and crypt abscess are characteristic histopathologic features. The thymus is important in immune regulation, and dysregulation of the immune system can be expected once its microenvironment is disrupted. We report the case of a 38-year-old woman with malignant thymoma without transplantation or transfusion history who initially presented with myasthenia gravis and clinically developed a GVHD-like syndrome with characteristic GVHD-like colitis on colonoscopy. We propose that disruption of the thymic microenvironment caused a dysregulated immune system and development of a GVHD-like syndrome.

Cow's milk-induced intestinal bleeding is a well-recognized cause of rectal bleeding in infancy. The authors report on 5 older children who presented with either visible rectal bleeding or profound anemia associated with occult intestinal bleeding secondary to cow's milk enteropathy.

Five children (3 boys and 2 girls) aged between 20 months and 9 years were referred for further investigation of gastrointestinal bleeding. Two had been investigated previously on multiple occasions, and both had undergone laparotomies with negative results. Further investigations showed evidence of allergic colitis in 3 detected only on proximal colonic biopsy findings.

In all cases, bleeding resolved completely after instituting a cow's milk-free diet. Two of the patients subsequently have undergone a cow's milk challenge leading to prompt recurrence of symptoms, which again resolved after simple dietary manipulation.

Cow's milk enteropathy may cause overt rectal bleeding or profound anemia from occult intestinal bleeding even in older children. Histological abnormalities in such cases may be confined to the proximal colon. After appropriate investigation, a trial of cow's milk exclusion should always be considered before laparotomy for obscure, chronic gastrointestinal bleeding in children.

Autoimmune enteropathy is normally characterised by crypt hyperplastic villous atrophy with enterocyte autoantibodies, activation of mucosal lymphocytes and increased epithelial HLA-DR. This case involved a severely affected Portuguese infant who was found to have lymphocyte activation deficiency and demonstrated correspondingly distinct mucosal features.

A female infant of nonconsanguineous parents was treated for vomiting and diarrhoea, first with milk exclusion and then with parenteral nutrition. Lymphocyte subsets and immunoglobulin concentrations were normal, but in vitro testing showed no activation in response to phytohaemagglutinin, Candida, or purified protein derivative, although the response to interleukin (IL)-2 was intact. Interleukin-2 deficiency was excluded. Analysis of jejunal biopsy specimens revealed only mild villous blunting with absent goblet cells, normal epithelial proliferation, and no crypt hyperplasia. The dense infiltrate of CD8+ and CD4+ T lymphocytes showed normal CD2 and CD3 expression but no activation or proliferation markers. HLA-DR was not increased on epithelium or lymphocytes. Thus, in addition to in vitro evidence for lymphocyte activation deficiency, the mucosal specimens showed no evidence of in situ T-cell activation.

After development of overwhelming septicaemia, the patient died at 18 months, just before a planned bone marrow transplant.

These findings confirm significant heterogeneity within autoimmune enteropathy. Formal immune function testing should be performed in all affected infants to identify T-cell activation deficiencies. The distinct mucosal findings suggest that activated T cells usually induce the crypt hyperplastic villous atrophy characteristic of classic autoimmune enteropathy.

Autoimmune enteropathy (AIE) is an entity reported primarily in infancy, resulting in intractable diarrhea and associated with small bowel villous atrophy and the presence of circulating anti-enterocyte (AEA) antibodies. It is a multisystem disorder with a response, in many cases, to immunosuppressive therapy.

We describe the case of an adult with autoimmune enteropathy consistent with both severe atrophic gastritis accompanying antral stenosis and colitis.

The patient, positive for anti-intrinsic factor antibody, had intractable diarrhea and protein-losing enteropathy. In the ileum inflammatory cells were observed infiltrating the lamina propria along with villus atrophy, and similar inflammation was also found in the lamina propria of the colon and stomach, with complete loss of specialized glands. The myenteric ganglion cells of the hypertrophied muscularis propria in the stenosed antrum showed degeneration with surrounding T-lymphocyte infiltration. There were more CD8+ than CD4 lymphocytes in the lamina propria of the stomach and colon.

The CD8+ (suppressor-cytotoxic) T lymphocytes may have played an important role in the production of lesions in the stomach, small intestine, and colon, so we propose this case as an example of a generalized autoimmune disorder of the alimentary tract.

The syndrome of intractable diarrhoea of infancy is heterogeneous and includes several diseases with diverse aetiologies. This study determines whether diagnostic categories can be defined on the basis of clinicopathological analysis.

European Society of Paediatric Gastroenterology, Hepatology and Nutrition members were surveyed to identify cases of intractable diarrhoea with persisting small intestinal enteropathy. A retrospective clinicopathological analysis was performed on cases showing life-threatening diarrhoea within the first 24 mo of life and requiring total parenteral nutrition, which were characterized by persistent villous atrophy, and resistance to therapy.

Forty-seven infants were identified with intractable diarrhoea. Villous atrophy was of varying degrees with (group I, n = 24) or without (group II, n = 18) lamina propria mononuclear cell infiltration. Group I presented later, had gut autoantibodies, and a higher prevalence of protein-losing enteropathy; a subset (group Ia, n = 12) also had extraintestinal symptoms of autoimmunity associated with a later onset of larger volume diarrhoea. Group II presented early; 8 cases (group IIa) had phenotypic abnormalities and a low birth weight; the remaining 10 (group IIb) showed mild-to-moderate villous atrophy, epithelial tufting, and abnormal crypts. Group III included five patients in whom no specific features were recognised. Twenty-one (45%) died at a median age of 24 months, 20 (43%) remained dependent on parenteral (n = 16) or enteral tube (n = 4) feeding, 4 (9%) received elimination diets plus other therapies, and 2 (4%) were lost to follow-up.

Clinicopathological analysis allowed distinct disease groups to be identified, allowing a provisional classification to be made. This straightforward approach forms a basis for future research in this exceptionally difficult paediatric condition.

The intractable diarrhoeas of infancy present very major problems of clinical management. However, the conceptual importance of these conditions lies in the information that they may provide about normal small-intestinal function in humans: among such infants will be found the human equivalents of the 'knock-out' mice, in which targeted gene disruption allows sometimes unexpected insight into the regulation of intestinal function. The challenge posed by the intractable diarrhoeal syndromes, of working backwards from an apparently common phenotype to probably multiple genotypes, is, however, immense. Very few of these conditions have been described at the genetic level, although the molecular basis of pathogenesis has been better explored in recent years. The two major groups of intractable diarrhoea are due to (1) primary epithelial abnormalities (which usually present within the first few days of life) and (2) immunologically mediated (which generally present after the first few weeks). The high prevalence of autoimmune enteropathy among infantile autoimmune disease, in contrast to adult autoimmunity, is intriguing and may reflect constitutive abnormality of extrathymic lymphocyte maturation. The use of potent immunosuppressive drugs and increasing expertise with parenteral nutrition are improving the outlook of these previously fatal conditions. Viewed globally, however, the pressing problem is to treat effectively the millions of infants who die from severe persistent diarrhoea and wasting, which would certainly not be considered intractable in wealthy countries.

Forty two infants below the age of 2 years presenting with chronic non-infective diarrhoea and shown to have histologically proved colitis were investigated over a five year period. Allergic colitis was the most common cause of colitis, accounting for 62% of the cases. Other colitides diagnosed included: non-specific colitis, autoimmune enterocolitis, and ulcerative colitis accounting for 10% each; severe combined immunodeficiency 7%, and Crohn's disease 3%. A positive family history and a personal history of atopy were obtained in 48% and 29% of the cases respectively. Serum immunoglobulin A, IgG2, and IgG4 were very low in over 50% of the entire cohort of infants with colitis; 66% of those with severe combined immunodeficiency, autoimmune enterocolitis, and ulcerative colitis (n = 11) had low CD3 and CD4 T lymphocytes with an accompanying increase in CD8 in two thirds of those with severe combined immunodeficiency. T lymphocytes were normal in those with allergic colitis. Thus infants with proved non-infective colitis as a group show a high prevalence of IgA, IgG2, and IgG4 deficiency. It is likely that this minor deficiency of mucosa associated immunoglobulin production has a role in the pathogenesis of the colitic process.

Intraocular inflammatory disease or uveitis, which affects the uveal tract and the retina of the eyes in human, is the major cause of visual impairment. Experimental autoimmune uveitis (EAU) is a T-cell-mediated autoimmune disease directed against retinal proteins and has been studied in several mammalian species including subhuman primates as a model for human posterior uveitis. Autoimmune responses provoked by molecular mimicry occur when the nonself and host determinants are similar enough to cross-react yet different enough to break immunological tolerance, and is one of the proposed mechanisms for induction of autoimmune diseases. Therapeutic immunomodulatory strategies have been used to induce antigen-specific peripheral immune tolerance in animal models of T-cell-mediated autoimmune diseases by oral administration of autoantigens. Oral tolerance leads to unique mechanisms of tissue and disease-specific immunosuppression, which would circumvent the immunotherapeutic problem of multiple target tissue autoreactivity. Several groups have investigated the effects of delivering autoantigens across gastric mucosal surfaces. This review briefly discusses molecular mimicry and the mechanism of induction of oral tolerance with respect to immunopathogenesis of T-cell-mediated autoimmune disease in general and EAU in particular.

Review of the medical records of 43 patients with common variable immunodeficiency (CVID) and 23 patients with X-linked agammaglobulinemia (XLAG) revealed a high incidence of chronic gastrointestinal complaints, most commonly diarrhea. Thirty-eight biopsies, four small-bowel resection specimens, and one autopsy from 10 patients with CVID and one patient with XLAG showed a wide range of abnormalities. A pattern resembling acute graft-versus-host disease, with apoptotic bodies and lymphocytes in crypts, was seen in the stomach (four patients), small bowel (three patients), and colon (three patients). Small-bowel specimens from three CVID patients with malabsorption showed mild to severe villous atrophy. Three CVID patients had Giardia in biopsies. Two cases of small bowel lymphoma associated with nodular lymphoid hyperplasia were identified in CVID patients. One patient's small bowel contained foamy histiocytes in the lamina propria, resembling Whipple's disease or chronic granulomatous disease, with numerous apoptotic bodies in crypts. Ultrastructurally, the histiocytes contained cellular debris. The patient with XLAG had recurrent fissuring necrosis of small bowel resembling Crohn's disease; a patient with CVID had colitis with features similar to ulcerative colitis. Poorly formed granulomas were seen in the stomach (one CVID patient) and the colon (two CVID patients). Lymphocyte populations were dominated by T cells; B cells were scarce except in lymphoid follicles in CVID patients with nodular lymphoid hyperplasia. Patients with CVID and XLAG manifest a spectrum of abnormalities in the gastrointestinal tract, with patterns superficially resembling graft-versus-host disease, inflammatory bowel disease, and Whipple's disease, but often lacking some of the diagnostic features of the diseases. Many of the CVID patients with chronic gastrointestinal complaints (62%) also had evidence of autoimmune phenomena, suggesting that in some patients the inflammatory process in the gastrointestinal tract has an autoimmune component.

Autoimmune enteropathy was initially described in young male infants presenting as severe secretory diarrhea. The disease is characterized by an inflammatory reaction which may involve several organs (bowel, pancreas, thyroid, kidneys, liver) with the presence of various circulating antibodies. The disease may also be observed in older children and in females with usually less bowel involvement. In view of the autoimmune basis of the disease, treatment requires immunosuppressive agents in addition to parenteral nutrition.

A 9-year-old boy with a 5-year history of severe protracted diarrhea requiring home parenteral nutrition and a 1 year history of abnormal liver function tests was admitted for duodenal, rectal, and liver biopsy. Duodenal biopsy results showed mild villus blunting, a mild lymphocytic infiltrate, and absent goblet cells. Paneth cells and endocrine cells could not be identified. Review of several previous biopsies showed an almost total absence of goblet cells by light microscopy. Anti-goblet cell antibodies of the immunoglobulin (Ig)G class were shown by immunofluorescence with a titer of 1:512. Histological examination of rectal mucosa also showed a total lack of goblet cells, orderly surface epithelial cells, and infiltration of the colonic crypts by lymphocytes. Immunoperoxidase staining of rectal mucosa showed increased numbers of lymphocytes with an excess of CD3+, CD45RO+ T cells, and increased numbers of B cells labeling with B1 and L26. Increased numbers of CD25+ (activated) lymphocytes were also observed. HLA/DR expression was striking and observed in both the crypt and surface enterocytes, as well as in the lamina propria. Immunological assessment of the patient showed an inverted CD4/CD8 ratio and IgA/IgG4 deficiency. The liver biopsy and radiological investigation were in keeping with chronic sclerosing cholangitis. Although a slight and transient improvement in histological appearances was observed with prednisolone there was no significant improvement of diarrhea. Trials of azothiaprine and oral cyclosporin did not result in clinical or histological improvement.

The intestine is exposed to a wide variety of macromolecules. Because macromolecules are antigenic, mechanisms have evolved in the gastrointestinal tract to regulate their absorption. Macromolecular uptake can be beneficial in delivering essential factors for growth and in sampling the antigenic milieu of the gastrointestinal tract. Specific transport mechanisms exist to execute this physiological absorption. However, inappropriate and uncontrolled antigen transport may occur in disease states, or as a prelude to disease states in the gastrointestinal tract. Such transport may result in immune responses that are harmful. In this review we examine both physiological transport of macromolecules through epithelia and through M cells. We also discuss uncontrolled transport and its relation to disease states. We conclude by examining the interrelationship between antigen transport and an altered immune system in the establishment of gastrointestinal disease.

Colitis is an important cause of abdominal pain and diarrhoea and is the main cause of blood and mucus in the stool. The inflammation can be due to infectious or to non-infectious causes, most commonly ulcerative colitis and Crohn's disease. However, a wide variety of rarer causes of colitis also present in childhood. These include colitis or enterocolitis secondary to Hirschsprung's disease and metabolic disorders (which include Hermansky-Pudlak syndrome, glycogen storage disease type 1b and pellagra). Primary inflammation of the colon is seen in microscopic and collagenous colitis, ulcerating enterocolitis of infancy, allergic colitis and autoimmune enteropathy. The histological pattern of each of these diseases has a characteristic picture and separates them from each other from ulcerative colitis and Crohn's disease. The pathophysiology of these rare forms of colitis in childhood is not clear; but in the future they may give us an insight into the pathogenesis of large bowel inflammation, particularly when the colitis occurs secondary to an established disease.

Three cases of X-linked auto-immune enteropathy with haemolytic anaemia and polyendocrinopathy are described from one related Japanese kindred. Two boys had died due to severe diarrhoea accompanied by total or subtotal intestinal villous atrophy. In contrast, although one patient showed the same symptoms and had circulating IgG antibodies against enterocytes, his condition improved dramatically and he developed well following the use of cyclosporin A (CSA). CSA may be beneficial in patients with this rare disorder. Auto-immune enteropathy should be considered as a cause of protracted diarrhoea with unknown aetiology.

The intestine is exposed to a wide variety of macromolecules. Because macromolecules are antigenic, mechanisms have evolved in the gastrointestinal tract to regulate their absorption. Macromolecular uptake can be beneficial in delivering essential factors for growth and in sampling the antigenic milieu of the gastrointestinal tract. Specific transport mechanisms exist to execute this physiological absorption. However, inappropriate and uncontrolled antigen transport may occur in disease states or as a prelude to disease states in the gastrointestinal tract. Such transport may result in immune responses that are harmful. This review examines physiological transport of macromolecules through epithelia and through M cells. It also considers uncontrolled transport and its relation to disease states. The review concludes with an examination of the interrelationship between antigen transport and an altered immune system in the establishment of gastrointestinal disease.