IgG4-related diseases are fibroinflammatory disorders affecting multiple organs, with autoimmune pancreatitis (AIP) being a common manifestation. Steroid therapy is effective in inducing remission but has complex effects on glucose metabolism. Diabetes occurs in 40% to 80% of AIP patients, and steroids can worsen glucose tolerance, although some studies suggest they may improve pancreatic endocrine function. An 81-year-old man with elevated IgG4 levels and imaging findings consistent with AIP initially declined treatment. His condition worsened, leading to poor glycemic management and referral to our hospital. Imaging confirmed AIP and tests showed impaired insulin and glucagon secretion. He was diagnosed with pancreatic diabetes secondary to IgG4-related AIP. Initially, intensive insulin therapy was administered, but within 3 months, both insulin and glucagon secretion declined significantly in the arginine-stimulation test, necessitating steroid therapy with prednisolone (35 mg/day) for the AIP. The high dose of steroid treatment enhanced both insulin and glucagon secretion capacities but gradually declined with dose tapering. On the other hand, although steroid therapy poses a temporary risk of hyperglycemia, it likely prevented further deterioration of pancreatic endocrine function.

Several studies found that early pancreatic atrophy detected by computed tomography (CT) within 6 months was associated with a high incidence of diabetes in patients with type-1 autoimmune pancreatitis (AIP) receiving steroid therapy; however, no long-term follow-up studies have been performed.

To investigate pancreatic volume (PV) changes using three dimensional (3D)-CT volumetry and their relationship with IgG4 and diabetes in patients with AIP.

This retrospective study included 33 patients with type-1 AIP receiving steroid therapy. Patients were divided into diffuse (D-type) and mass-forming type (M-type) AIP. PV was determined by semi-automated 3D-CT volumetry, and changes between initial and follow-up values were calculated. The relationship between PV and serum IgG4 levels was analyzed by Spearman's rank correlation. The PV atrophy ratio compared with the presumed normal PV at the time of last follow-up CT and its relationship with diabetes were investigated.

There were 16 D-type and 17 M-type patients with long-term follow-up (mean, 95.8 months). The regression curve of mean relative PV change reduced exponentially and rapidly during the first 25 months and then more slowly in both groups. The overall cumulative pancreas re-enlargement rates at 1, 3, 5, 7 and 10 years were 6.1%, 12.2%, 29.2%, 47.5% and 55.0%, respectively. There was a moderate-to-very strong positive correlation (ρ ≥ 0.4) between PV and serum IgG4 levels in nine (9/13, 69.2%) patients. All 33 patients showed pancreatic atrophy (mean 59.3%) after long-term follow-up. Patients with D-type AIP had a significantly higher atrophy rate and higher incidence of diabetes than M-type patients (P < 0.05).

PV change initially reduced exponentially and then more slowly and is considered an important factor associated with diabetes. Serum IgG4 levels were positively correlated with PV during follow-up.

A high prevalence of diabetes mellitus (DM) coexisting with autoimmune pancreatitis (AIP) is observed. However, evidence on the circumstances under which corticosteroid therapy (CST) for AIP improves or worsens DM is scarce. This study aimed to demonstrate and identify predictors of DM control under the influence of CST.

Patients diagnosed with type 1 AIP were enrolled from a prospectively maintained cohort and were classified into three groups according to the chronology in which AIP and DM were diagnosed: pre-existing DM (pDM), concurrent DM (cDM), and non-DM (nDM). The responses of DM to CST were assessed when corticosteroid was ceased or tapered to a maintenance dose and classified as 'improvement' and 'non-improvement' (including 'no change' and 'exacerbation').

Among 101 patients with type 1 AIP, 52 (51.5%) patients were complicated with DM at the time of AIP diagnosis, with 36 patients in the cDM group and 16 patients in the pDM group. The incidences of diffuse pancreatic swelling (72.2%) and pancreatic body/tail involvement (91.7%) were significantly higher in the cDM group than in both the pDM and nDM groups. Of the 52 patients with DM, CST was administered in 48 cases. Multivariate logistic analysis identified that elevated serum gamma-glutamyl transferase (GGT) level at AIP diagnosis [odds ratio (OR) = 0.032, 95% confidence interval (CI): 0.003-0.412, P = 0.008] and pancreatic atrophy after CST (OR = 0.027, 95% CI: 0.003-0.295, P = 0.003) were negatively associated with DM control improvement.

Patients with diffuse pancreatic swelling and pancreatic body/tail involvement in pancreatitis tended to be complicated with cDM at AIP diagnosis. CST exerted a beneficial effect on the clinical course of DM in nearly half of the AIP patients complicated with DM at diagnosis, particularly in those without elevated serum GGT levels at diagnosis and who did not experience pancreatic atrophy after CST.

Hormones play a crucial role in growth development; however, the impact of testosterone suppression (TS) on craniofacial growth during puberty remains inconclusive. This study aimed to evaluate the impact of TS during puberty on cephalometric measurements and histological characteristics of facial growth centers.

Thirty-six heterogenic Wistar male rats were randomly allocated into experimental orchiectomy (ORX) and control (sham) groups. At an age of 23 days (prepubertal stage), orchiectomy and placebo surgery were performed. Cephalometric measurements were performed via lateral cephalograms during and after puberty. The animals were euthanized at an age of 45 days (pubertal stage) and 73 days (postpubertal stage). Histological slices of the growth centers (condyle, premaxilla, and median palatine suture) were stained with hematoxylin and eosin, and sirius red. Student's t or Mann-Whitney U tests were used to compare linear and angular cephalometric measurements across groups (α error = 5%).

Linear and angular measurements were statistically different in ORX animals (cranial bones, maxilla, and mandible) at 45 days and 73 days. Condylar histology showed a decrease in prechondroblast differentiation and a delay of mineralization in ORX animals. Vascularization of the medium palatine suture was lower in the ORX group at 45 days. Type I and III collagen fiber synthesis was lower in the ORX groups. In the premaxillary suture, collagen fibers were better organized in the sham groups.

Our results suggest that testosterone suppression affects craniofacial growth during puberty.

To investigate factors influencing glycemic control in diabetes mellitus complicated by autoimmune pancreatitis.

This retrospective cohort study investigated 33 patients with diabetes mellitus complicated by autoimmune pancreatitis who had received steroid therapy at Toranomon Hospital between January 1, 2011, and December 31, 2020. The course of glycemic control at 12 months after starting steroids was classified into three groups: Improved, Unchanged, or Worsened. Factors affecting these groups were investigated. Furthermore, we created two scores: (1) time of diabetes mellitus onset and baseline body mass index; (2) time of diabetes mellitus onset and baseline C-peptide index. Diabetes mellitus occurring at the same time as autoimmune pancreatitis, body mass index ≥22 kg/m2 , and C-peptide index ≥1.1 were each worth 1 point. Scores were summed and totals of 0-2 were compared between groups.

Ten patients were in the Improved group, 10 were in the Unchanged group, and 13 were in the Worsened group. The baseline body mass index and baseline C-peptide index were lower in the Worsened group than in the Improved group (P < 0.05 each). In addition, the scores were lower in the Worsened group than in the other groups (P < 0.05).

Patients with a lower baseline body mass index and a decreased baseline C-peptide index may experience worse glycemic control on steroid therapy.

Autoimmune pancreatitis (AIP) is a specific form of chronic pancreatitis with a high relapse rate after treatment. AIP patients are burdened with an increased risk of long-term sequelae such as exocrine and endocrine insufficiency. Our objective was to investigate if pharmacological treatment affects both endocrine and exocrine pancreatic function in patients with AIP.

We included 59 patients with definite AIP in the final analysis. Screening for diabetes mellitus (DM) and pancreatic exocrine insufficiency (PEI) was performed at the time of AIP diagnosis and during follow-up.

There were 40 (67.8%) males and 19 (32.2%) females; median age at diagnosis was 65 years. Median follow-up after the diagnosis of AIP was 62 months. PEI prevalence at diagnosis was 72.7% and was 63.5% at follow-up. The cumulative incidence of DM was 17.9%, with a prevalence of DM at diagnosis of 32.8%. No strong association was found between pharmacological treatment and occurrence of PEI and DM. Univariate analysis identified potential risk factors for PEI (other organ involvement and biliary stenting) and for DM (overweight, blue-collar profession, smoking, weight loss or obstructive jaundice as presenting symptoms, imaging showing diffuse pancreatic enlargement, smoking). In a multivariate analysis, only obstructive jaundice was identified as a risk factor for DM both at diagnosis and during follow-up.

Our results suggest that the prevalence of endocrine and exocrine insufficiency in AIP is high at diagnosis with an additional risk of PEI and DM during follow-up despite pharmacological treatment.

Autoimmune pancreatitis (AIP) is a rare form of pancreatitis that may lead to endocrine and exocrine insufficiency if left untreated. AIP clinically responds to glucocorticoids (GCs) therapy, but multiple GCs courses are often required to maintain remission with detrimental effects on glycaemic control.

In this systematic review and meta-analysis, we aimed to assess the rate of endocrine and of exocrine insufficiency at diagnosis and at follow up in patients with AIP as well as the impact of GC therapy on pancreatic function in the long-term.

The MEDLINE, SCOPUS, and EMBASE databases were searched from inception to August 2021 to identify studies reporting data on endocrine and exocrine insufficiency in patients with AIP. Pooled events were calculated using a random-effect model and expressed in terms of pooled prevalence rates.

A total of 6522 AIP patients and sixty-two studies were included in the analysis. The pooled estimate rate for the overall prevalence of diabetes in AIP at baseline was 37% (95% CI 32-42, I2 96%). The pooled prevalence rate of exocrine insufficiency was 45% (95%CI 32.9-57.4; I2 97%). The pooled estimate rate of diabetes at follow-up was 44% (95%CI 26.1-62.4) in studies where GCs were given to 100% of patients and 42% (95%CI 30.6-52.9) in studies where GCs were given to less than 100% of patients.

A large proportion of patients with AIP displays concomitant exocrine and endocrine insufficiency at the time of diagnosis. The incidence of diabetes at the longest available follow up tends to increase in patients treated with GCs.

The indications for maintenance glucocorticoid therapy (MGT) and its duration after initial remission of type 1 autoimmune pancreatitis (AIP) remain controversial. In contrast to the Japanese treatment protocol, the Mayo protocol does not recommend MGT after initial remission. This study aimed to evaluate the relapse rate in patients with type 1 AIP according to the duration of glucocorticoid therapy.

We conducted a systematic literature review up until November 30, 2020, and identified 40 studies reporting AIP relapse rates. The pooled relapse rates were compared between groups according to the protocol and duration of glucocorticoids (routine vs. no MGT; glucocorticoids ≤6 months vs. 6-12 months vs. 12-36 months vs. ≥ 36 months). The pooled rates of adverse events related to glucocorticoids were also evaluated.

Meta-analysis indicated calculated pooled relapse rates of 46.6% (95% confidence interval (CI), 38.9-54.3%) with glucocorticoids for ≤ 6 months, 44.3% (95% CI, 38.8-49.8%) for 6-12 months, 34.1% (95% CI, 28.6-39.7%) for 12-36 months, and 27.0% (95% CI, 23.4-30.6%) for ≥ 36 months. The rate of relapse was also significantly lower in patients with routine-use protocol of MGT (31.2%; 95% CI, 27.5-34.8%) than in patients with no MGT protocol (44.1%; 95% CI, 35.8-52.4%). Adverse events were comparable between groups.

The rate of relapse tended to decrease with extended durations of glucocorticoid therapy up to 36 months. Clinicians may decide the duration of glucocorticoids according to patient condition, including comorbidities and risk of relapse.

A 65-year-old man with ulcerative colitis presented with aggravated diabetes. Computed tomography showed two masses in the body and tail of the pancreas. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) was performed, with histopathological findings suggesting autoimmune pancreatitis (AIP). Type-2 AIP was suspected, and administration of prednisolone was initiated. The pancreatic masses had disappeared after the treatment. In this case, EUS-FNA was effective for the diagnosis of type-2 AIP. The two-lesion mass formation observed here is a rare presentation of the disease. In patients with a history of ulcerative colitis, the possibility of late-onset type-2 AIP should be kept in mind.

IgG4-related disease (IgG4-RD) has only existed as a unique disease entity since 2003, yet remarkable progress has already been achieved in describing the essential features of the disease. A framework for systematic clinical studies has been created by the development of a quantitative disease activity tool (the IgG4-RD Responder Index) and the validation of classification criteria, both of which were the products of international, multi-centre investigations. In addition, substantial strides have been made in understanding the pathophysiology of IgG4-RD. In particular, the central role of B cells in the disease has been demonstrated by both the robust clinical responsiveness of IgG4-RD to B cell depletion and by the identification of multiple self-antigens that promote B cell expansion. CD4⁺ T cells have also been investigated in detail; CD4⁺ cytotoxic T lymphocytes (suspected of promoting disease) and a specific T follicular helper cell subset that contributes to IgG4 isotype switching have both been defined by multiple groups. The mechanisms by which these immune cells converge on target tissues, interact with fibroblasts and promote tissue remodelling are beginning to be understood and will be an important research focus in the coming years.

The overall objective of these guidelines is to provide evidence-based recommendations for the diagnosis and management of immunoglobulin G4 (IgG4)-related digestive disease in adults and children. IgG4-related digestive disease can be diagnosed only with a comprehensive work-up that includes histology, organ morphology at imaging, serology, search for other organ involvement, and response to glucocorticoid treatment. Indications for treatment are symptomatic patients with obstructive jaundice, abdominal pain, posterior pancreatic pain, and involvement of extra-pancreatic digestive organs, including IgG4-related cholangitis. Treatment with glucocorticoids should be weight-based and initiated at a dose of 0.6-0.8 mg/kg body weight/day orally (typical starting dose 30-40 mg/day prednisone equivalent) for 1 month to induce remission and then be tapered within two additional months. Response to initial treatment should be assessed at week 2-4 with clinical, biochemical and morphological markers. Maintenance treatment with glucocorticoids should be considered in multi-organ disease or history of relapse. If there is no change in disease activity and burden within 3 months, the diagnosis should be reconsidered. If the disease relapsed during the 3 months of treatment, immunosuppressive drugs should be added.

Autoimmune pancreatitis (AIP) is frequently complicated by diabetes mellitus (DM), but DM associated with AIP is reported to improve after steroid therapy. The aim of this study is to investigate glucose intolerance during steroid therapy according to the onset of DM.

Sixty-one patients who underwent steroid therapy for AIP were included into this study. We evaluated C peptide index (CPI), homeostasis model assessment for insulin resistance (HOMA-R), and the pancreatic diameter at AIP diagnosis and after 4 weeks, 1 year, and 2 years of steroid therapy. Patients were categorized into three groups according to DM onset: Pre-existing DM (pDM), concurrent DM (cDM), and non-DM (nDM).

Forty-three patients (71%) had DM: 15 pDM and 28 cDM. At AIP diagnosis, CPI was lower in patients with pDM (0.7, P = 0.007) and cDM (0.9, P = 0.018) than nDM (1.3). After 4 weeks of steroid therapy, CPI improved in cDM (P < 0.001) and in nDM (P = 0.021). After 2 years of steroid therapy, HOMA-R increased (2.1-3.0, P = 0.007) but CPI gradually improved (1.0-2.1, P = 0.004). DM improved in 23% of cDM, and 55% of insulin users in cDM discontinued using insulin. Pancreatic atrophy was seen in 30%, and was associated with DM.

DM in patients with AIP was associated with impaired insulin secretion rather than insulin resistance. Insulin secretion improved during steroid therapy for AIP in patients with concurrent DM. Thus, glucose intolerance can be an indication for AIP treatment.

Autoimmune pancreatitis (AIP), a unique subtype of pancreatitis, is often accompanied by systemic inflammatory disorders. AIP is classified into two distinct subtypes on the basis of the histological subtype: immunoglobulin G4 (IgG4)-related lymphoplasmacytic sclerosing pancreatitis (type 1) and idiopathic duct-centric pancreatitis (type 2). Type 1 AIP is often accompanied by systemic lesions, biliary strictures, hepatic inflammatory pseudotumors, interstitial pneumonia and nephritis, dacryoadenitis, and sialadenitis. Type 2 AIP is associated with inflammatory bowel diseases in approximately 30% of cases. Standard therapy for AIP is oral corticosteroid administration. Steroid treatment is generally indicated for symptomatic cases and is exceptionally applied for cases with diagnostic difficulty (diagnostic steroid trial) after a negative workup for malignancy. More than 90% of patients respond to steroid treatment within 1 month, and most within 2 weeks. The steroid response can be confirmed on clinical images (computed tomography, ultrasonography, endoscopic ultrasonography, magnetic resonance imaging, and 18F-fluorodeoxyglucose-positron emission tomography). Hence, the steroid response is included as an optional diagnostic item of AIP. Steroid treatment results in normalization of serological markers, including IgG4. Short- and long-term corticosteroid treatment may induce adverse events, including chronic glycometabolism, obesity, an immunocompromised status against infection, cataracts, glaucoma, osteoporosis, and myopathy. AIP is common in old age and is often associated with diabetes mellitus (33-78%). Thus, there is an argument for corticosteroid therapy in diabetes patients with no symptoms. With low-dose steroid treatment or treatment withdrawal, there is a high incidence of AIP recurrence (24-52%). Therefore, there is a need for long-term steroid maintenance therapy and/or steroid-sparing agents (immunomodulators and rituximab). Corticosteroids play a critical role in the diagnosis and treatment of AIP.

Autoimmune pancreatitis (AIP) is a well-recognized fibroinflammatory disease of the pancreas. Despite the significant number of studies published on AIP type 1 and 2, no studies have been focused on AIP type not otherwise specified (NOS) and therefore very little is known about clinical features and long-term outcomes of these patients. The aim of this study was to investigate clinical and radiological features of AIP type NOS-patients.

Patients classified as AIP type NOS at clinical onset included in our database prospectively maintained since 1995 were evaluated. Epidemiological, clinical data were collected and analyzed.

Forty-six patients were included in the study. The clinical onset was mainly characterized by weight loss, jaundice and acute pancreatitis. Eight patients (17.4%) were reclassified as AIP type 2 during follow-up because of the development of ulcerative colitis. Seven patients (15.2%) experienced relapse after steroid treatment but only one (2.2%) needed immunosuppressive drugs because of recurrent relapses.

AIP type NOS shares clinical features similar to AIP type 2 and a relevant proportion of patients was reclassified as AIP type 2 during follow-up because of the development of ulcerative colitis. The risk of relapse is low but not irrelevant.

Glucocorticoid therapy is effective for treating autoimmune pancreatitis, but autoimmune pancreatitis itself and steroid therapy aggravate glycemic control. A 77-year-old man with type 2 diabetes was consulted due to aggravation of glycemic control. He was diagnosed with autoimmune pancreatitis. We promptly started glucocorticoid therapy for autoimmune pancreatitis and insulin therapy for glycemic control. Subsequently, both pancreatitis and diabetes were markedly ameliorated. After stopping glucocorticoid therapy, good glycemic control continued with diet therapy alone. Starting glucocorticoid therapy at an early stage of autoimmune pancreatitis is very important for preserving the insulin secretory capacity and improving glycemic control.

Risk for relapse after induction of remission with steroid therapy has been studied extensively in patients with autoimmune pancreatitis (AIP), but findings have been equivocal. We performed a systematic review and meta-analysis to estimate the relapse rate of AIP after initial remission after steroid treatment and to identify factors associated with relapse.

Three reviewers searched MEDLINE, SCOPUS, and EMBASE until July 2018 to identify studies on rate of relapse of AIP after induction of remission with steroid therapy. A pooled estimate was calculated using the DerSimonian and Laird method for a random-effects model. This study was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

Thirty-six studies met the inclusion criteria for meta-analysis. The median follow-up time was 40.8 months. Fifty-two percent of patients were classified as having type 1 AIP. The pooled estimate of relapse rate was 33% (95% CI, 30%-37%). A higher proportion of patients with type 1 AIP had a relapse compared with patients with type 2 AIP (37.5% vs 15.9%; P < .001). We found significant heterogeneity among studies (P < .01). Long-term maintenance therapy with steroids and study quality were associated independently with AIP relapse, after we adjusted for year of publication by multivariate meta-regression.

In a systematic review and meta-analysis, we found that a large proportion of patients with AIP treated successfully with steroid induction therapy had a relapse (33%)-particularly patients with type 1 AIP (37%). Maintenance steroid therapy lasting longer than 1 year could reduce risk of relapse. However, the data characterizing relapse rates are of limited quality, indicating the need for randomized controlled trials and new immunosuppressive drugs.

A 66-year-old Japanese male presented with thirst, polyuria, and hemoglobin A1c and postprandial glucose levels (13.1% and 529 mg/dL, respectively) that indicated severe hyperglycemia. Based on his high immunoglobulin G4 level and the results of magnetic resonance imaging and magnetic resonance cholangiopancreatography, we diagnosed him with autoimmune pancreatitis. Insulin was initiated to control his diabetes. One month later, the patient commenced on prednisolone therapy for the treatment of autoimmune pancreatitis, after which his total insulin dosage increased to a maximum of 52 units/day. When the prednisolone dosage was later tapered, the patient's total dosage of insulin was reduced to 42 units/day. However, he had gained 3.6 kg from the start of prednisolone therapy, and 42 units/day was insufficient for maintaining glycemic control. Thus, empagliflozin, a sodium-dependent glucose transporter 2 (SGLT2) inhibitor, was added. Thereafter, we were able to reduce the patient's total dosage of insulin; it was eventually discontinued with good glycemic control and weight loss. Such results suggest that the combination of insulin with an SGLT2 inhibitor may be a viable option for the treatment of diabetic patients on prednisolone therapy.

Steroids are the first-line drugs for induction of remission in patients with type 1 autoimmune pancreatitis (AIP), and the usefulness of steroid maintenance therapy to prevent relapse has recently been reported. However, even during steroid therapy, a relatively large percentage of patients relapse and the predictive factors for relapse have not yet been elucidated. The aim of this study was to clarify the predictive factors for relapse of AIP patients during steroid therapy.

The medical records of 76 patients with type 1 AIP with continued steroid therapy after induction of remission were analyzed retrospectively. The relapse rate during steroid therapy was evaluated, and the risk factors for relapse were investigated by univariate and multivariate analysis of clinical factors.

Relapse occurred in 28.9% (22/76) of the patients. The cumulative relapse rates were 10.5% at 1 year, 25.0% at 3 years, 34.9% at 5 years, and 43.0% at 10 years. In multivariate analysis, presence of sclerosing dacryoadenitis/sialadenitis at the time of initial diagnosis of AIP was an independent risk factor for relapse (HR 3.475, p = .009). The cumulative relapse rates of patients with sclerosing dacryoadenitis/sialadenitis reached 21.4% at 1 year, 56.0% at 3 years, and 78.0% at 5 years.

Sclerosing dacryoadenitis/sialadenitis was a predictive factor for relapse in type 1 AIP during steroid therapy; in such cases, strict follow-up is necessary with relapse in mind.

Autoimmune pancreatitis (AIP) is a rare disease, and data from countries like India concerning its clinical presentation and long-term outcomes are scarce. We retrospectively evaluated the clinical presentation, imaging features and treatment outcomes of patients with AIP.

We carried out a retrospective analysis of our database to identify patients diagnosed with and treated for AIP at our unit in a tertiary care hospital in North India.

Eighteen patients with AIP (mean age: 54.9±11.1 years; 13 male) were evaluated. Of these, 9 (50%) patients had probable type 1 AIP, 2 (11%) patients probable type 2 AIP, and 4 (22%) definite type 1 AIP. Patients with type 2 AIP were significantly younger than patients with type 1 (40.0±2.8 vs. 58.4±9.6 years). In type 1 AIP, other organ involvement was observed in 3/18 (17%) patients, whereas both patients with type 2 AIP had coexisting ulcerative colitis. The diagnosis of AIP was made after resective surgery in 6/18 (33.0%) patients. An accurate diagnosis of AIP could be made in all patients who underwent resection or core biopsy, but cytological examination after endoscopic ultrasound-guided fine-needle aspiration could not provide a definitive diagnosis in any patient. Initial treatment with steroids was given to 12 (67%) patients, with a 100% response, but the disease relapsed in 5/13 (38%) patients over a mean follow-up period of 34.2±21.6 weeks.

AIP is not rare in India and the majority of clinical manifestations, imaging features, treatment response and long-term outcomes are similar to those reported in the literature.

Immunoglobulin G4-related disease (IgG4-RD) is an uncommon disorder that demonstrates characteristic clinicopathologic features including sclerosing lesions with storiform fibrosis, increased IgG4+ plasma cells with an increased IgG4+/IgG+ plasma cell ratio, obliterative phlebitis, and often an increased serum IgG4 level. This review summarizes the characteristic histopathologic and clinical features of IgG4-RD with detailed discussion of the histopathologic characteristics of the most commonly involved anatomic sites. We also present recent advances in our understanding of the pathophysiologic mechanisms of IgG4-RD and discuss updates on the treatment, prognosis, and outcomes of this rare disease, including discussion of the possible association between IgG4-RD and malignancy.

Autoimmune pancreatitis (AIP) is a subset of inflammatory pancreatic disease, responsive to corticosteroid therapy. It is prone to being affected by diabetes mellitus, but the effectiveness of steroid therapy on pancreatic endocrine function is still controversial. We present a case of AIP, focusing on pancreatic endocrine function after steroid therapy.

The patient was referred to our hospital with exacerbation of diabetic control and pancreatic swelling. By admission, the insulin secretory capacity was severely impaired. The patient was diagnosed with AIP and treated with prednisolone, resulting in marked improvement of the pancreatic swelling. Glycemic control worsened transiently after initiation of steroid therapy, but insulin requirements decreased along with tapering prednisolone dosage. Pancreatic cytology showed that the acinar structure had been destroyed, and the islets had disappeared. Insulin and glucagon immunostaining revealed slightly scattered alpha and beta cells within the fibrotic stroma. The patient notably showed improved pancreatic alpha cell function predominantly after steroid therapy, despite partial improvement of beta cell function.

An imbalance between alpha and beta cell function may contribute to insufficient diabetic control in some patients with AIP. The pancreatic endocrine function test in combination with pancreatic cytology could be helpful when considering the treatment strategy for diabetic control in patients with AIP.