Standard steroid treatment for autoimmune pancreatitis

'Can we cure IgG4-related diseases?'

IgG4-related disease (IgG4-RD), recognized as a novel clinical entity, is a rare, chronic, immune-mediated systemic fibroinflammatory disorder of unknown origin with either synchronous or metachronous multi-organ involvement. Although the pathogenic mechanism remains unclear, possible multipathogenic factors such as genetic backgrounds, disease-specific or related antigens, and abnormal innate or adaptive immunity may be involved. Many immunocytes, including neutrophil extracellular trap, M2 macrophage, plasmablast, B cells, and T-cells (Th2-CD4+T, follicular helper T cells, and CD4+SLAMF7+cytotoxic T cells) play important roles in the pathogenesis. Conventional therapies with glucocorticoid or rituximab in combination with/without immunomodulators are recommended in all symptomatic patients with active IgG4-RD. Because of a few of randomized clinical trials, the comprehensive management for IgG4-RD has not been established yet. Targeted treatment approaches against the plasmablast to B cell lineage and the CD4+SLAMF7+cytotoxic T cell seem to be promising for the future-directed treatment.

Pancreatic Ductal Adenocarcinoma with Autoimmune Pancreatitis: A Case Report and Literature Review

A 50-year-old man was diagnosed with type 1 autoimmune pancreatitis (AIP) following endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) and a histopathological examination. After six months of untreated follow-up, the serum IgG4 level decreased, and the diffuse pancreatic enlargement improved; however, a pancreatic head mass became apparent. EUS-FNA of this mass revealed pancreatic ductal adenocarcinoma (PDAC) with IgG4-positive plasma cells. In addition, the resected specimen revealed PDAC, without any features of AIP. After pancreatoduodenectomy, AIP did not recur. The development of AIP in this case could be related to paraneoplastic syndrome.

Clinical features and long-term prognosis of type 1 autoimmune pancreatitis based on the location of bile duct lesions

BACKGROUND/PURPOSE

Type 1 autoimmune pancreatitis (AIP) frequently involves biliary lesions and poses diagnostic and therapeutic challenges. We aimed to evaluate the clinical features and long-term prognosis of type 1 AIP with a focus on the locations of bile duct lesions.

METHODS

In this retrospective study, 159 patients with type 1 AIP were included. Patients were classified on the basis of the location of bile duct strictures, and clinical outcomes, including relapse rates and steroid dependency, were analyzed.

RESULTS

Eighty-nine (56%) patients had bile duct involvement. Forty-nine patients (30.8%) experienced relapse, with a significantly higher cumulative relapse rate in cases of stricture or wall thickening upstream of the intrapancreatic bile duct (3 years: 24% vs. 37.1%, p < .001). These patients also had a significantly higher rate of two or more relapses than did the patients without stricture or wall thickening (5.1% vs. 19.5%, p = .01). Two patients with stricture and dilation up to the intrahepatic bile ducts became steroid-dependent and were treated with azathioprine.

CONCLUSIONS

Patients with type 1 AIP with biliary lesions involving upstream strictures or wall thickening, especially those with stricture and dilation extending into the intrahepatic bile ducts, are at high risk of relapse and may become steroid dependent.

Management of IgG4-related cholangitis: diagnosis, therapy, and long-term surveillance

IgG4-related cholangitis (IRC) is a chronic cholestatic liver disease that often occurs concomitantly with autoimmune pancreatitis type 1. Both conditions are manifestations of IgG4-related disease, a systemic autoimmune-mediated fibroinflammatory disorder. Patients often present with jaundice and weight loss, mimicking hepatobiliary malignancies, such as cholangiocarcinoma, primary sclerosing cholangitis, and pancreatic cancer. Accurate diagnosis is challenging due to the absence of pathognomonic findings but can be achieved using the HISORt criteria (histology, imaging, serology, other organ involvement, and response to immunosuppressive therapy). Early diagnosis is critical to avoid unnecessary surgery and prevent progression to liver fibrosis or cirrhosis. IRC responds well to corticosteroid therapy, though relapses are common, necessitating long-term immunosuppressive treatment in many cases. Steroid-sparing agents for remission induction and maintenance therapy comprise immunomodulators, such as azathioprine, as well as B-cell depletion therapies, such as rituximab. This review provides a structured clinical overview of the diagnosis, differential diagnosis, and therapy, including novel therapeutic options, such as inebilizumab, for this rare yet severe condition. A key focus is on long-term surveillance strategies, which include laboratory tests, imaging (contrast-enhanced magnetic resonance imaging/magnetic resonance cholangiopancreatography, ultrasound, endosonography), and, particularly in patients with fibrotic bile duct strictures, endoscopy (endoscopic retrograde cholangiopancreatography, cholangioscopy).

Epidemiological and economical burden of cholestatic liver disease

The main cholestatic liver diseases comprise primary sclerosing cholangitis, primary biliary cholangitis, and IgG4-related cholangitis. Despite being classified as rare diseases, these are becoming gradually more important in the field of hepatology since their incidence is slowly rising while the viral hepatitis burden is declining. Cholestatic liver diseases now rank among the 3 most frequent indications for liver transplantation in many Western countries. An accurate understanding of the epidemiology and burden of disease on both the individual and society of cholestatic diseases is of great importance. This review aims to provide a comprehensive overview of the current literature on the epidemiology, health-related quality of life, and economic burden of primary sclerosing cholangitis, primary biliary cholangitis, and IgG4-related cholangitis.

Effects of Steroid Therapy on Pancreatic Endocrine Function in IgG4-related AIP: Evaluation by Arginine Stimulation Test

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.

Avoiding Unnecessary Surgery in Autoimmune Pancreatitis: Lessons From a Four-Patient Case Series and Literature Review

Autoimmune pancreatitis (AIP) is an inflammatory disease that may be mistaken for pancreatic cancer, especially when there is a focal lesion in the pancreatic head. It often involves biliary strictures and occasional tumor marker elevations, causing confusion with malignancy. An incomplete assessment might lead to unwarranted surgery for what is actually an inflammatory process. By combining imaging, histopathology, IgG4 measurement, and the clinical response to steroids, physicians can reach the correct diagnosis more reliably. We describe four adults, ages 64 to 84, who had obstructive jaundice, biliary dilation, and imaging findings suggesting a possible pancreatic head tumor. Tumor marker levels varied; some were elevated, while others were unremarkable. In two instances, imaging raised concerns about vascular involvement. Endoscopic ultrasound-guided biopsies showed lymphoplasmacytic inflammation without malignant cells, and all patients had elevated IgG4 levels that decreased with steroid therapy. Each individual underwent endoscopic biliary stenting and began a course of prednisone, leading to a return of normal liver function and improvement in imaging findings. Two required short-term additional stent management for persistent strictures, and three underwent gallbladder removal due to associated disease. All four avoided major pancreatic surgery and had a favorable clinical course. These cases show the importance of a methodical workup that includes IgG4 assessment and biopsy confirmation. Steroid therapy can resolve clinical and radiologic abnormalities once AIP is recognized. This approach spares many patients from extensive operations when their presumed neoplasm is, in reality, an autoimmune condition.

Update on Autoimmune Pancreatitis and IgG4-Related Disease

Autoimmune pancreatitis is an increasingly recognized inflammatory type of subacute pancreatitis; two subtypes of autoimmune pancreatitis have been identified so far: the "lymphoplasmacytic" type 1 variant and the "neutrophilic" type 2 variant. Type 1 autoimmune pancreatitis represents the most common manifestation of IgG4-related disease, a fibro-inflammatory disorder characterized by elevated IgG4 levels in the serum and affected tissues. Type 2 autoimmune pancreatitis is a pancreas-specific disorder that frequently occurs in the context of inflammatory bowel diseases. Due to the complexity of both diseases, a comprehensive work up with imaging, laboratory, and histological studies is required to achieve a diagnosis and rule out malignancies. Glucocorticoids represent the cornerstone of the treatment, often supported by other immunosuppressive drugs in case of steroid intolerance or aggressive disease. Maintenance treatment is often employed in type 1 autoimmune pancreatitis because of the higher relapse rate compared with type 2 autoimmune pancreatitis. In this review, we summarize the key concept of autoimmune pancreatitis, delve into the differential diagnosis between the two subtypes, and cover the recent relevant research findings and pressing unmet needs.

Navigating the labyrinth: Phenotypes of IgG4-related disease

ABSTRACT

We report a case of an elderly female with subacute submental neck swelling, dry cough, and a history of significant weight loss. Unexpectedly, a left submandibular chronic sialadenitis was noted on ultrasound of the neck, along with a thyroid nodule that, on biopsy, showed lymphocytic infiltration. High-resolution computed tomography of the lungs revealed multifocal irregular consolidations with lymphadenopathy, and possible infective causes, including tuberculosis, were ruled out after a thorough microbiological evaluation. It was only after a positron emission tomography-guided lung biopsy with specialized immunohistochemical staining was performed that the diagnosis of IgG4-related disease (IgG4-RD) was confirmed. Our patient exhibited overlapping features of head and neck-limited and Mikulicz/systemic phenotype of IgG4. In this case report, we highlight the clinical phenotypes of IgG4-RD, their respective differential diagnoses, and discuss our approach to this challenging case.

IgG4-related Disease: Recent Topics on Immunological Aspects of This Disorder and Their Application in New Treatment Strategies

IgG4-related disease (IgG4-RD) is a systemic and chronic inflammatory disorder that can affect every part of the body. The formation of tertiary lymphoid tissues (TLT) in the affected organs may be a key phenomenon in understanding the pathogenesis of this disease because T follicular helper (Tfh) 2 cells play an important role in IgG4 class switching within TLT in the affected organs or tissues. TLT formation leads to the formation of masses or swelling of the affected organs. Interleukin (IL)-4 and IL-10 are critical cytokines for IgG4-class switching and are produced in TLT. Other factors, such as CD4-positive (CD4+) cytotoxic T cells, M2 macrophages, and LAG3+ Tfh cells, have been identified as disease-specific contributors to lesion formation. In this review, I describe the current knowledge necessary to understand the pathogenesis of this disease and recent developments in treatment strategies beyond B-cell depletion therapy.

Pancreatic volume change using three dimensional-computed tomography volumetry and its relationships with diabetes on long-term follow-up in autoimmune pancreatitis

BACKGROUND

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.

AIM

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

METHODS

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.

RESULTS

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).

CONCLUSION

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.

New insights into predictors of autoimmune pancreatitis relapse after steroid therapy

OBJECTIVES

While autoimmune pancreatitis (AIP) responds well to steroid therapy, the high relapse rate in type 1 AIP remains a critical problem. The present study examined predictors of relapse of type 1 AIP following steroid therapy.

MATERIALS AND METHODS

Nine factors potentially predictive of relapse were analyzed in 81 AIP patients receiving steroid therapy with follow-up ≥ 12 months. The rate of serum IgG4 decrease following steroid therapy was calculated by dividing the difference between serum IgG4 values before and at two months after the start of steroid by the IgG4 value before steroid.

RESULTS

A relapse occurred in 11 patients (13.5%) during a median of 38 months. Multivariate analysis revealed that the presence of IgG4-related retroperitoneal fibrosis (HR: 5.59; 95% CI: 1.42-22.0; p = 0.014) and the low rate of serum IgG4 decrease after steroid therapy (HR: 0.048; 95% CI: 0.005-0.46; p = 0.008) were significant, independent predictors of AIP relapse. The cut-off value based on receiver operating characteristic curve data for the rate of serum IgG4 decrease before and at two months after steroid therapy distinguishing patients with and without a relapse was 0.65. Using this cut-off value, the area under the curve, sensitivity, and specificity were found to be 0.63, 0.73, and 0.60, respectively.

CONCLUSION

The low rate of serum IgG4 decrease after the start of steroid therapy and the presence of IgG4-related retroperitoneal fibrosis were predictive of type 1 AIP relapse. Cautious, gradual tapering of steroid dosage and longer maintenance therapy are recommended for patients with these factors.

A suspected case of serum IgG4-negative type 1 autoimmune pancreatitis detected due to localized pancreatic duct narrowing: a case report

A 50-year-old woman was referred to our hospital with elevated serum amylase levels. Physical examination revealed no jaundice or abdominal tenderness. Serum IgG4 was negative. Computed tomography revealed a localized pancreatic duct narrowing in the pancreatic head, with caudal pancreatic duct dilation and an intraductal papillary mucinous neoplasm. Pancreatic enlargement was not observed. Endoscopic ultrasonography (EUS) showed a small hypoechoic mass. Although EUS-guided, fine-needle aspiration was performed, no diagnosis was established. Endoscopic retrograde pancreatography showed a localized narrowing in the main pancreatic duct of the pancreatic head. A biopsy of the narrowing was performed through the minor papilla because of difficult access from the major papilla. The specimen showed the infiltration of numerous IgG4-positive plasma cells, suggesting type 1 autoimmune pancreatitis (AIP). Six months later, magnetic resonance cholangiopancreatography revealed improvement in the narrowing without specific treatment. The patient presented with localized narrowing of the pancreatic duct and caudal duct dilation, which was distinct from pancreatic cancer. Diagnostic difficulties arose from negative serum IgG4 results, the lack of typical imaging characteristics of AIP, and failure to meet the AIP criteria according to the relevant Japanese and international guidelines. However, AIP was suspected and surgery was successfully avoided through a biopsy.

Efficacy of Rituximab in Autoimmune-Mediated IgG4 Pancreaticobiliary Disease: A Systematic Review and Meta-Analysis

BACKGROUND AND AIMS

IgG4 pancreaticobilliary disease (IgG4-PBD) typically shows a rapid improvement with glucocorticoid treatment, yet most patients experience a recurrence. Rituximab (RTX) has emerged as a hopeful approach to prevent relapses in IgG4-PBD. Nevertheless, there is a lack of data on the efficacy and safety of RTX in IgG4-PBD. In this study, we aim to perform a systematic review and meta-analysis to study the pooled efficacy of RTX in this patient population.

METHODS

Multiple databases, including MEDLINE, SCOPUS, and Embase, were searched (in March 2024) using specific terms for studies evaluating the efficacy and safety of RTX in IgG4 pancreatic biliary disease. Outcomes of interest were relapse, remission, partial remission rates, and adverse events. Standard meta-analysis methods were used using the random-effects model. I2% heterogeneity was used to assess the heterogeneity.

RESULTS

Twelve studies were included in the study (257 patients). The pooled rate of complete remission was 68% (54% to 80%), I2 =53%, respectively. The pooled relapse rate was 23% (13% to 36%), I2=64%. The pooled rate of total adverse events was 21% (12% to 35%), I2=52%. The pooled partial remission rate is 16% (7% to 32%), I2=25%. The pooled rate of complete and partial remission was 81% (66% to 90%), I2=75%. The pooled infusion reaction and infection were 12% (7% to 18%), I2=0% and 14% (8% to 22%), I2=16%, respectively.

CONCLUSION

RTX therapy appears effective in inducing and maintaining remission of pancreaticobiliary disease with a low rate of side effects. RTX presents as a promising treatment option for patients grappling with recurrent or unresponsive IgG4-related ailments. In addition, RTX emerges as an attractive alternative for individuals intolerant to steroids or experiencing IgG4-related disease relapses. Future studies comparing RTX with other immunomodulators will offer deeper insights into relapse factors and elucidate the appropriateness of utilizing this maintenance treatment following the initial flare.

Immunoglobulin G4-Related Disease Presenting as Recurrent Acute Pancreatitis

Immunoglobulin G4-related disease (IgG4-RD) is a rare immune-mediated disease affecting multiple organs and tissues. There is often the presence of elevated serum Ig4 subtype with histological evidence of lymphoplasmacytic infiltration, fibrosis, and phlebitis. The mainstay of treatment is steroid therapy. This case report is based on a 24-year-old man with IgG4-related type 1 autoimmune pancreatitis (AIP) who also had elevated serum IgG4 subclass and histological features in keeping with IgG4-RD. The main complaints were dry cough, nasal congestion with sneezing, sore throat, and fever. Necessary investigations were performed and based on the International Consensus Diagnostic Criteria, the diagnosis of AIP type 1 was confirmed, which is a pancreatic manifestation of IgG4-RD. He was subsequently treated with prednisolone and azathioprine and is showing a good response to the treatment.

Clinical characteristics, imaging diagnostic accuracy, and prognosis of autoimmune pancreatitis: A real-world study in China

OBJECTIVE

In this study we aimed to comprehensively evaluate the clinical features and treatment outcomes of Chinese patients with autoimmune pancreatitis (AIP) through a single-center real-world study.

METHODS

Patients diagnosed with AIP in Changhai Hospital, Naval Medical University from January 2014 to December 2021 were included. Baseline characteristics, laboratory test results, cross-sectional imaging and endoscopic ultrasound (EUS) findings, and long-term follow-up data were obtained. The differences in these characteristics between type 1 and type 2 AIP patients were analyzed.

RESULTS

Among all 320 patients, 271 (84.7%) and 49 (15.3%) had type 1 and type 2 AIP, respectively. The most common initial symptom was abdominal discomfort (58.1%), followed by obstructive jaundice (32.5%). Extrapancreatic organ involvement was identified in 126 (39.4%) patients, with the biliary system being the most commonly involved (36.6%). Elevated serum IgG4 level was rare in type 2 AIP patients. The diagnostic accuracy of computed tomography (CT), magnetic resonance imaging (MRI), and EUS for definitive and probable AIP were 78.0%, 68.7%, and 80.5%, respectively. EUS-guided tissue acquisition with immunohistochemical staining helped establish a final diagnosis in 39.7% of patients. During the follow-up period of 60 months, 18.6% of patients experienced relapse. The 1-, 3-, and 5-year relapse rates were higher in type 1 AIP patients, with an accumulated rate of 8.0%, 12.6%, and 15.1%, when compared with those with type 2 AIP.

CONCLUSIONS

Type 2 AIP is not uncommon in Chinese population. The diagnostic accuracy of CT and EUS for AIP might be superior to that of MRI.

Diabetes mellitus in patients with type 1 autoimmune pancreatitis at diagnosis and after corticosteroid therapy

BACKGROUND

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.

METHODS

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').

RESULTS

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.

CONCLUSIONS

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.

IgG4-related disorders of the gastrointestinal tract: Experience from a tertiary care centre with systematic review of Indian literature

INTRODUCTION

IgG4-related disease (IgG4-RD) is a rare disease entity in India. We aimed at studying the clinical profile of IgG4-RD of gastrointestinal tract (GIT) from our centre, while systematically reviewing data from India.

METHODS

Retrospective review of IgG4-RD of GIT was done using electronic medical records between January 2013 and July 2022. Literature search was done for studies of IgG4-RD of the GIT reported from India from 2000 till January 2023. Case series, case reports of IgG4-RD of GIT and case reports describing GIT with multi-organ involvement were included in the review. Primary outcome measure was response to treatment. Secondary outcome measure was relapse after remission.

RESULTS

Thirty-one patients were included with 71% (22/31) having autoimmune pancreatitis. The diagnosis was achieved on surgical specimen in 35% (11/31) patients. Steroid was given to 64% (20/31) patients with remission achieved in 70% (14/20) patients. Four patients exhibitted response to prolonged course of steroids with maintenance azathioprine. Relapse was seen in four (20%) patients who achieved remission. Of 731 articles screened, 48 studies (four case series and 44 case reports) were included in the literature review. Of 95 patients described, steroids were given to 65.2% (62/95), while surgery was done in 33.6% (32/95). Remission was seen in 96.6% (85/88) with relapse occurring in 11.4% (10/88) patients on follow-up.

CONCLUSION

One-third patients of IgG4-RD of GIT are diagnosed after surgery. Response to steroids is good with relapse occurring in up to 12% patients.

IgG4-related disease-rare but you should not forget it

Immunoglobulin G4-related disease is a systemic immune-mediated disease with insidious evolution characterized by fibroinflammatory lesions over virtually any organ system. Despite the remarkable progression of knowledge, its etiology remains undefined. Due to its relapse-remitting pattern, it could accumulate irreversible damage, increasing comorbidities and mortality. This paper emphasizes key concepts for diagnosing and treating patients with this condition.

Type 1 Autoimmune Pancreatitis in Europe: Clinical Profile and Response to Treatment

BACKGROUND & AIMS

Autoimmune pancreatitis (AIP) is an immune-mediated disease of the pancreas with distinct pathophysiology and manifestations. Our aims were to characterize type 1 AIP in a large pan-European cohort and study the effectiveness of current treatment regimens.

METHODS

We retrospectively analyzed adults diagnosed since 2005 with type 1 or not-otherwise-specified AIP in 42 European university hospitals. Type 1 AIP was uniformly diagnosed using specific diagnostic criteria. Patients with type 2 AIP and those who had undergone pancreatic surgery were excluded. The primary end point was complete remission, defined as the absence of clinical symptoms and resolution of the index radiologic pancreatic abnormalities attributed to AIP.

RESULTS

We included 735 individuals with AIP (69% male; median age, 57 years; 85% White). Steroid treatment was started in 634 patients, of whom 9 (1%) were lost to follow-up. The remaining 625 had a 79% (496/625) complete, 18% (111/625) partial, and 97% (607/625) cumulative remission rate, whereas 3% (18/625) did not achieve remission. No treatment was given in 95 patients, who had a 61% complete (58/95), 19% partial (18/95), and 80% cumulative (76/95) spontaneous remission rate. Higher (≥0.4 mg/kg/day) corticosteroid doses were no more effective than lower (<0.4 mg/kg/day) doses (odds ratio, 0.428; 95% confidence interval, 0.054-3.387) and neither was a starting dose duration >2 weeks (odds ratio, 0.908; 95% confidence interval, 0.818-1.009). Elevated IgG4 levels were independently associated with a decreased chance of complete remission (odds ratio, 0.639; 95% confidence interval, 0.427-0.955). Relapse occurred in 30% of patients. Relapses within 6 months of remission induction were independent of the steroid-tapering duration, induction treatment duration, and total cumulative dose.

CONCLUSIONS

Patients with type 1 AIP and elevated IgG4 level may need closer monitoring. For remission induction, a starting dose of 0.4 mg/kg/day for 2 weeks followed by a short taper period seems effective. This study provides no evidence to support more aggressive regimens.

Recent advances in IgG4-related autoimmune pancreatitis

The incidence of IgG4-related autoimmune pancreatitis (IgG4-AIP) is high in Asia and other countries, and unnecessary treatment is often undertaken due to both missed diagnosis and misdiagnosis in clinical practice. Although IgG4-AIP has attracted increasing attention, the details of IgG4-AIP pathogenesis and systemic immune response, including its relationship to tumor pathogenesis, are still unclear. In recent years, research on serum immunological detection, pathological features, clinical manifestations, diagnosis and treatment measures for IgG4-AIP has gradually increased. It is of great importance to summarize and discuss the latest progress regarding IgG4-AIP disease.

Withdrawal of immunosuppressants and low-dose steroids in patients with stable IgG4-RD (WInS IgG4-RD): an investigator-initiated, multicentre, open-label, randomised controlled trial

OBJECTIVES

IgG4-related disease (IgG4-RD) is an immune-mediated, fibroinflammatory disease. Induction treatment with glucocorticoid (GC) is usually effective, but its tendency of relapse makes the strategy for maintenance treatment a challenge. The WInS IgG4-RD (withdraw immunosuppressants (IMs) and steroid in stable IgG4-RD) trial tested whether discontinuation of GC and IM was feasible in stable IgG4-RD.

METHODS

The WInS IgG4-RD trial was a multicentre, open-label, randomised controlled trial. Patients with IgG4-RD receiving GC+IM as maintenance treatment with clinically quiescent disease for at least 12 months were randomised (1:1:1) into three groups: group 1: withdraw GC+IM; group 2: withdraw GC but maintain IM; group 3: maintain GC+IM. The primary outcome was the relapse rate of disease within 18 months. The secondary outcomes included the changes of IgG4-RD Responder Index (RI), Physician's Global Assessment (PGA), serum IgG4 and IgG, as well as adverse events.

RESULTS

One hundred and forty-six patients were randomised, with 48 patients in group 1, 49 patients in group 2 and group 3, respectively. Within the 18-month follow-up period, disease relapse occurred in 25 out of 48 (52.1%) patients in group 1 vs 7 out of 49 (14.2%) in group 2 and 6 out of 49 (12.2%) in group 3 (p<0.001). The changes in RI and PGA were significantly higher in group 1 than in group 2 (p<0.001) or group 3 (p<0.001).

CONCLUSIONS

The maintenance of IMs, with or without low-dose GC, was found to be superior to withdraw GC+IM in preventing relapse for long-time stable IgG4-RD.

TRIAL REGISTRATION NUMBER

NCT04124861.

Current and future advances in practice: IgG4-related disease

IgG4-related disease (IgG4-RD) is an increasingly recognized cause of fibroinflammatory lesions in patients of diverse racial and ethnic backgrounds and is associated with an increased risk of death. The aetiology of IgG4-RD is incompletely understood, but evidence to date suggests that B and T cells are important players in pathogenesis, both of which are key targets of ongoing drug development programmes. The diagnosis of IgG4-RD requires clinicopathological correlation because there is no highly specific or sensitive test. Glucocorticoids are highly effective, but their use is limited by toxicity, highlighting the need for studies investigating the efficacy of glucocorticoid-sparing agents. B cell-targeted therapies, particularly rituximab, have demonstrated benefit, but no randomized clinical trials have evaluated their efficacy. If untreated or under-treated, IgG4-RD can cause irreversible organ damage, hence close monitoring and consideration for long-term immunosuppression is warranted in certain cases.

A Diagnostic Paradox: Identifying IgG4-Related Disease in a Patient Previously Diagnosed with Sjogren's Syndrome

We present the case of a 77-year-old male with a history of rectal adenocarcinoma and Sjogren's disease who was admitted for severely elevated liver function tests. Cross-sectional imaging demonstrated a dilated bile duct, and eventual biopsy of the area showed fibrosis and lymphocytic infiltrate consistent with IgG4-related disease. The patient was treated with rituximab and a prednisone taper. This case discusses the clinical, laboratory, and imaging hallmarks of this rare disease and illustrates the practical challenges of distinguishing it from other rheumatologic conditions.

A single-centre retrospective study of factors affecting steroid-free remission of immunoglobulin G4-related disease conducted in South Korea: A notable outcome after complete resection

OBJECTIVES

Few studies have examined factors affecting steroid-free remission (SFR) in patients with immunoglobulin G4-related disease (IgG4-RD). The aim of this study was to investigate clinical factors affecting SFR in IgG4-RD.

METHODS

The medical records of 68 patients who met the 2020 revised comprehensive diagnostic criteria for IgG4-RD were reviewed retrospectively. SFR was defined as remission maintained for at least 6 months without corticosteroids. Cox regression analysis was performed to examine the associations between SFR and various clinical factors. The relapse rate after SFR was examined using the log-rank test.

RESULTS

After a median follow-up of 36 months, 30.9% (21/68) of patients with IgG4-RD achieved SFR. Multivariate Cox regression analysis revealed that IgG4-RD diagnosed by complete resection rather than by common diagnostic procedures was the only factor positively associated with SFR (hazard ratio, 7.41; 95% confidence interval, 2.23-24.60; P = .001). Furthermore, relapse after attainment of SFR was significantly less common in the group that underwent complete resection than in the group that did not undergo complete resection (log-rank P = .006).

CONCLUSIONS

Patients with IgG4-RD diagnosed by complete resection had a higher likelihood of achieving SFR and a lower rate of relapse after attaining SFR.

Relapse and side effects of steroid therapy beyond 3 years in autoimmune pancreatitis: A multicenter retrospective study

BACKGROUND

The impact of extended steroid administration on patients with autoimmune pancreatitis after a 3-year maintenance period remains poorly understood. This study analyzed the advantage and disadvantage of continuing steroid therapy beyond 3 years.

METHODS

In this retrospective multicenter study across 17 institutions, patients who successfully completed 3 years of maintenance therapy without experiencing relapse were categorized into two groups: the maintenance therapy discontinuation group, who discontinued steroid therapy after the initial 3-year period, and maintenance therapy continuation group, who continued steroid therapy beyond 3 years. The cumulative relapse rate after 3 years of maintenance therapy was the primary outcome. Relapse predictors were compared using the Gray test for cumulative relapse incidence by specific factor.

RESULTS

Of 211 patients, 105 experienced no relapse during the 3-year maintenance therapy and were divided into two groups: 69 in the maintenance therapy discontinuation group and 36 in the maintenance therapy continuation group. The relapse rate was lower in the maintenance therapy continuation group than in the maintenance therapy discontinuation group (P = 0.035). Predictors of relapse after 3 years included cessation of maintenance therapy (hazard ratio [HR] = 3.76; 95 % confidence interval [CI] = 1.07-13.3, P = 0.040) and renal involvement (HR = 2.88; 95 % CI = 1.04-7.99, P = 0.042). The maintenance therapy continuation group showed a significantly higher prevalence of macrovascular complications, compared with the maintenance therapy discontinuation group (P = 0.005).

CONCLUSIONS

Cessation of steroid maintenance therapy and renal involvement were predictors of relapse after 3 years of maintenance therapy. However, the long-term use of steroids may increase the risk of macrovascular complications.

IgG4-related pancreatobiliary diseases could be associated with onset of pancreatobiliary cancer: A multicenter cohort study

BACKGROUND

The risk and prognosis of pancreatobiliary cancer and in patients with autoimmune pancreatitis (AIP) and IgG4-related sclerosing cholangitis (IgG4-SC) remain unclear. Therefore, we retrospectively investigated the risk of pancreatobiliary cancer and prognosis in patients with AIP and IgG4-SC.

METHODS

Patients with AIP and IgG4-SC at seven centers between 1998 and 2022 were investigated. The following data were evaluated: (1) the number of cancers diagnosed and standardized incidence ratio (SIR) for pancreatobiliary and other cancers during the observational period and (2) prognosis after diagnosis of AIP and IgG4-SC using standardized mortality ratio (SMR).

RESULTS

This study included 201 patients with AIP and IgG4-SC. The mean follow-up period was 5.7 years. Seven cases of pancreatic cancer were diagnosed, and the SIR was 8.11 (95% confidence interval [CI]: 7.29-9.13). Three cases of bile duct cancer were diagnosed, and the SIR was 6.89 (95% CI: 6.20-7.75). The SMR after the diagnosis of AIP and IgG4-SC in cases that developed pancreatobiliary cancer were 4.03 (95% CI: 2.83-6.99).

CONCLUSIONS

Patients with autoimmune pancreatitis and IgG4-SC were associated with a high risk of pancreatic and bile duct cancer. Patients with AIP and IgG4-SC have a worse prognosis when they develop pancreatobiliary cancer.

Autoimmune pancreatitis: Cornerstones and future perspectives

Autoimmune pancreatitis (AIP) is an autoimmune subtype of chronic pancreatitis resulting from the aberrant immune response against the pancreas, leading to inflammation and fibrosis. Although AIP is rare, its incidence is increasing and is often misdiagnosed as other pancreatic diseases. AIP is commonly classified into two types. Type 1 AIP (AIP-1) is typically associated with elevated serum immunoglobulin G4 (IgG4) levels and systemic manifestations, while type 2 AIP is typically a more localized form of the disease, and may coexist with other autoimmune disorders, especially inflammatory bowel diseases. Additionally, there is emerging recognition of a third type (type 3 AIP), which refers to immunotherapy-triggered AIP, although this classification is still gaining acceptance in medical literature. The clinical manifestations of AIP mainly include painless jaundice and weight loss. Elevated serum IgG4 levels are particularly characteristic of AIP-1. Diagnosis relies on a combination of clinical, laboratory, radiological, and histological findings, given the similarity of AIP symptoms to other pancreatic disorders. The mainstay of treatment for AIP is steroid therapy, which is effective in most cases. Severe cases might require additional imm-unosuppressive agents. This review aims to summarize the current knowledge of AIP, encompassing its epidemiology, etiology, clinical presentation, diagnosis, and treatment options. We also address the challenges and controversies in diagnosing and treating AIP, such as distinguishing it from pancreatic cancer and managing long-term treatment, highlighting the need for increased awareness and knowledge of this complex disease.

A Case of Castleman's Disease with a Marked Infiltration of IgG4-Positive Cells in the Renal Interstitium

Multicentric Castleman's disease (MCD) is a benign lymphoproliferative disorder with heterogenous clinical symptoms, and involves systemic organs in addition to lymph nodes. Herein, we present the case of a 55-year-old man with MCD characterized by an extensive infiltration of IgG4+ plasma cells in the kidneys. The patient presented to our hospital with a high fever and diarrhea. On admission, laboratory analysis revealed anemia, renal dysfunction (eGFR 30 mL/min/1.73 m2), polyclonal gammopathy (IgG 7130 mg/dL), elevated serum IgG4 level (2130 mg/dL), and increased C-reactive protein (8.0 mg/dL). An enlargement of lymph nodes in the axillary, mediastinal, para-aortic, and inguinal regions was observed on abdominal computed tomography. Axillary lymph node biopsy revealed interfollicular expansion due to dense plasma cell infiltration. Renal biopsy demonstrated significant plasma cell infiltration into the tubulointerstitium. Immunohistochemical analysis showed a 40% IgG4-positive/IgG-positive plasma cell ratio, meeting the diagnostic criteria for an IgG4-related disease. Amyloid A deposition was observed along vessel walls, and immunofluorescence analysis indicated granular positivity of IgG and C3 along the glomerular capillary wall. Elevated levels of interleukin-6 (21 pg/mL) and vascular endothelial growth factor (VEGF; 1210 pg/mL) were noted. Based on these findings, and the histological finding of the lymph node biopsy, idiopathic MCD was diagnosed. Corticosteroid monotherapy was only partially effective. Subsequently, tocilizumab administration was initiated, leading to sustained remission, even after discontinuation of prednisolone. Due to the diverse responses to steroid therapy and the varying prognoses observed in MCD and IgG4-related disease, it is essential to carefully diagnose MCD by thoroughly assessing the organ distribution of the disease, its response to steroid therapy, and any additional pathological findings.

Proteomics: Unraveling the Cross Talk Between Innate Immunity and Disease Pathophysiology, Diagnostics, and Treatment Options

Inflammation is crucial in diseases, and proteins play a key role in the interplay between innate immunity and pathology. This review explores how proteomics helps understanding this relationship, focusing on diagnosis and treatment. We explore the dynamic innate response and the significance of proteomic techniques in deciphering the complex network of proteins involved in prevalent diseases, including infections, cancer, autoimmune and neurodegenerative disorders. Proteomics identifies key proteins in host-pathogen interactions, shedding light on infection mechanisms and inflammation. These discoveries hold promise for diagnostic tools, therapies, and vaccines. In cancer research, proteomics reveals innate signatures associated with tumor development, immune evasion, and therapeutic response. Additionally, proteomic analysis has unveiled autoantigens and dysregulation of the innate immune system in autoimmunity, offering opportunities for early diagnosis, disease monitoring, and new therapeutic targets. Moreover, proteomic analysis has identified altered protein expression patterns in neurodegenerative diseases like Alzheimer's and Parkinson's, providing insights into potential therapeutic strategies. Proteomics of the innate immune system provides a comprehensive understanding of disease mechanisms, identifies biomarkers, and enables effective interventions in various diseases. Despite still in its early stages, this approach holds great promise to revolutionize innate immunity research and significantly improve patient outcomes across a wide range of diseases.

Efficacy and Safety of Inebilizumab in IgG4-Related Disease: Protocol for a Randomized Controlled Trial

INTRODUCTION

Immunoglobulin G4-related disease (IgG4-RD) is a debilitating multiorgan disease characterized by recurring flares leading to organ dysfunction, decreased quality of life, and mortality. Glucocorticoids, the standard of care for IgG4-RD, are associated with substantial treatment-related toxicity. Inebilizumab, an antibody directed against CD19, mediates the rapid and durable depletion of CD19+ B cells thought to be involved in IgG4-RD pathogenesis. We describe the first international, prospective, double-blind, placebo-controlled trial to evaluate the safety and efficacy of B-cell depletion for flare prevention in IgG4-RD (MITIGATE).

METHODS

The study was designed by an international panel of physicians with expertise in IgG4-RD. Critical trial design decisions included the selection of participants, definition of clinically meaningful primary and secondary endpoints, accommodation of standard of care, and development of flare diagnostic criteria. The study is approved for conduct in 22 countries.

PLANNED OUTCOMES

The primary efficacy endpoint is time from randomization to the occurrence of the first centrally adjudicated and investigator-treated disease flare during the 1-year randomized controlled period. A set of novel, organ-specific flare diagnostic criteria were developed specifically for this trial, incorporating symptoms and signs, laboratory findings, imaging study results, and pathology data. MITIGATE aims to accrue 39 flares for the primary endpoint, which provides sufficient power to detect a relative risk reduction of 65% in the inebilizumab group. It is anticipated that enrollment of 160 participants will achieve this goal. Additional endpoints include safety, annualized flare rate, flare-free complete remission, quality-of-life measures, and cumulative glucocorticoid use. MITIGATE represents the first randomized, double-blind, placebo-controlled trial of any treatment strategy conducted in IgG4-RD. Data from this study will provide insights into the natural history and pathophysiology of IgG4-RD and the efficacy and safety of B-cell depletion as a therapeutic avenue.

TRIAL REGISTRATION

NCT04540497.

Long-term Outcomes after Steroid Pulse Therapy in Patients with Type 1 Autoimmune Pancreatitis

Objective Steroid pulse therapy is a regimen involving the intravenous administration of supra-pharmacological doses of corticosteroids in the short term. It is used to treat various inflammatory and autoimmune conditions. However, the strengths and limitations of steroid pulse therapy for induction of remission in type 1 autoimmune pancreatitis (AIP) are unknown. Methods Depending on the steroid therapy regimen administered, the 104 patients with type 1 AIP included in this retrospective study were divided into three groups: conventional oral prednisolone (PSL) regimen (PSL group), intravenous methylprednisolone (IVMP) pulse followed by oral PSL regimen (Pulse+PSL group), and IVMP pulse-alone regimen (Pulse-alone group). We then examined the relapse rate and adverse events among the three groups. Results The Kaplan-Meier estimates of the relapse rate at 36 months after steroid therapy were 13.6% in the PSL group, 13.3% in the Pulse+PSL group, and 46.2% in the Pulse-alone group. The log-rank test revealed that the relapse-free survival in the Pulse-alone group was significantly shorter than that in the PSL (p=0.024) and Pulse+PSL groups (p=0.014). The exacerbation of glucose tolerance after steroid therapy was less frequently observed in the Pulse-alone group (0%) than in the PSL group (17%, p=0.050) and Pulse+PSL groups (26%, p=0.011). Conclusion Although treatment with IVMP pulse alone resulted in unsatisfactory relapse prevention outcomes compared with conventional steroid therapy, the IVMP pulse-alone regimen might be an alternative treatment strategy for type 1 AIP from the perspective of avoiding adverse events from steroids.

IgG4-related digestive diseases: diagnosis and treatment

IgG4-related digestive diseases encompass a group of chronic inflammatory disorders characterized by autoimmune reactions and fibrosis affecting multiple digestive organs. These diseases are identified by elevated serum levels of IgG4 and the presence of IgG4-positive plasma cell infiltration in the affected sites, along with storiform fibrosis, obliterative phlebitis, and eosinophilic infiltration. Although extensive research has been conducted, a comprehensive understanding of these conditions remains elusive. Current clinical diagnosis often relies on the application of integrated diagnostic criteria for IgG4-related diseases, combined with specific organ involvement criteria. Distinguishing them from malignancies poses considerable challenges. Moreover, further investigations are required to elucidate the underlying pathogenic mechanisms and explore potential therapeutic interventions. This review provides a systematic classification of IgG4-related digestive diseases while discussing their diagnostic strategies, clinical presentations, and treatment modalities. The comprehensive insights shared herein aim to guide clinicians in their practice and contribute to the advancement of knowledge in this field.

Type 1 Autoimmune Pancreatitis Masquerading as Pancreatic Head Carcinoma

Obstructive jaundice is a joint clinical presentation with many etiologies, including pancreatic cancer and autoimmune pancreatitis (AIP). Differentiating between these two conditions is pivotal due to the divergent management approaches and prognoses. In this case report, we present a case of a 49-year-old female patient who presented with weight loss, intermittent chronic abdominal pain, and jaundice. She was initially suspected of having pancreatic cancer because of clinical presentation and imaging findings. However, she was ultimately diagnosed with Type 1 AIP due to histopathology findings and elevated immunoglobulin G4. This case highlights the complexities in diagnosis, the role of advanced imaging techniques and tissue sampling, and the lessons learned regarding managing this challenging clinical scenario.

Clinical characteristics and outcome of autoimmune pancreatitis based on serum immunoglobulin G4 level: A single-center, retrospective cohort study

BACKGROUND

Autoimmune pancreatitis (AIP) has been linked with elevated immunoglobulin (Ig) G4 levels. The characteristics and outcomes of AIP based on serum markers have not been fully evaluated.

AIM

To compare clinical features, treatment efficacy, and outcome of AIP based on serum IgG4 levels and analyze predictors of relapse.

METHODS

A total of 213 patients with AIP were consecutively reviewed in our hospital from 2006 to 2021. According to the serum IgG4 level, all patients were divided into two groups, the abnormal group (n = 148) with a high level of IgG4 [> 2 × upper limit of normal (ULN)] and the normal group (n = 65). The t-test or Mann-Whitney U test was used to compare continuous variables. Categorical parameters were compared by the χ2 test or Fisher's exact test. Kaplan-Meier curves and log-rank tests were established to assess the cumulative relapse rates. Univariate and multivariate analyses were used to investigate potential risk factors of AIP relapse.

RESULTS

Compared with the normal group, the abnormal group had a higher average male age (60.3 ± 10.4 vs 56.5 ± 12.9 years, P = 0.047); higher level of serum total protein (72.5 ± 7.9 g/L vs 67.2 ± 7.5 g/L, P < 0.001), IgG4 (1420.5 ± 1110.9 mg/dL vs 252.7 ± 106.6 mg/dL, P < 0.001), and IgE (635.6 ± 958.1 IU/mL vs 231.7 ± 352.5 IU/mL, P = 0.002); and a lower level of serum complement C3 (100.6 ± 36.2 mg/dL vs 119.0 ± 45.7 mg/dL, P = 0.050). In addition, a lower number of cases with abnormal pancreatic duct and pancreatic atrophy (23.6% vs 37.9%, P = 0.045; 1.6% vs 8.6%, P = 0.020, respectively) and a higher rate of relapse (17.6% vs 6.2%, P = 0.030) were seen in the abnormal group. Multivariate analyses revealed that serum IgG4 [(> 2 × ULN), hazard ratio (HR): 3.583; 95% confidence interval (CI): 1.218-10.545; P = 0.020] and IgA (> 1 × ULN; HR: 5.908; 95%CI: 1.199-29.120; P = 0.029) and age > 55 years (HR: 2.383; 95%CI: 1.056-5.378; P = 0.036) were independent risk factors of relapse.

CONCLUSION

AIP patients with high IgG4 levels have clinical features including a more active immune system and higher relapse rate. Several factors, such as IgG4 and IgA, are associated with relapse.

Relapse rate and predictors of relapse after cessation of glucocorticoid maintenance therapy in type 1 autoimmune pancreatitis: a multicenter retrospective study

BACKGROUND

Type 1 autoimmune pancreatitis responds well to glucocorticoid therapy with a high remission rate. Moreover, glucocorticoid maintenance therapy can help prevent relapse. However, the relapse rate following cessation of long-term glucocorticoid therapy is unknown. The aim of this study was to clarify the relapse rate and predictors of relapse following long-term glucocorticoid therapy cessation.

METHODS

We analyzed 94 patients who achieved remission after undergoing glucocorticoid therapy, discontinued treatment after at least 6 months of maintenance therapy, and were subsequently followed up for at least 6 months. The patients were divided into three groups based on treatment duration (< 18, 18-36, and ≥ 36 months), and their relapse rates were compared. Univariate and multivariate analyses of clinical factors were conducted to identify relapse predictors.

RESULTS

After discontinuing glucocorticoid therapy, relapse was observed in 43 (45.7%) patients, with cumulative relapse rates of 28.2% at 1 year, 42.1% at 3 years, 47.0% at 5 years, and a plateau of 77.6% at 9 years. Of the 43 patients who relapsed, 25 (58.1%) relapsed within 1 year after after cessation of glucocorticoid therapy. Relapse and cumulative relapse rates did not differ significantly according to treatment duration. In the multivariate analysis, an elevated serum IgG4 level at the time of glucocorticoid cessation was found to be an independent predictor of relapse (hazard ratio, 4.511; p < 0.001).

CONCLUSIONS

A high relapse rate occurred after cessation of glucocorticoid maintenance therapy, regardless of the duration of maintenance therapy, especially within the first year after cessation. However, the normalization of long-term serum IgG4 levels may be a factor in considering cessation.

Clinical features of IgG4-associated autoimmune pancreatitis and factors related to its recurrence

BACKGROUND

IgG4-associated autoimmune pancreatitis (IgG4-AIP) is a kind of autoimmune-mediated pancreatitis. The clinical manifestations of IgG4-AIP are not specific and the differential diagnosis is often difficult, and the indications and course of glucocorticoid treatment for the disease are still controversial. The aim of this study was to improve the understanding, diagnosis, and treatment of the disease by analyzing the clinical characteristics of the disease, and to reduce the recurrence rate of the disease by analyzing the factors related to its recurrence.

AIM

To investigate the clinical features, therapeutic efficacy, and recurrence of IgG4-AIP.

METHODS

The clinical data of 46 patients with IgG4-AIP were analyzed retrospectively.

RESULTS

The male to female ratio of IgG4-AIP patients was 10.5:1. The most common clinical manifestation was obstructive jaundice. Approximately 52.1% of patients had extrapancreatic organ involvement, with the most commonly affected extrapancreatic organ being the bile duct. The vast majority (91.3%) of patients had higher serum IgG4 levels than normal. The imaging findings were diffuse swelling or local enlargement of the pancreas with stricture of the biliary and pancreatic ducts. The majority (81.2%) of patients underwent pancreatic biopsy under the guidance of endoscopic ultrasonography. Typical pathological findings included fibrous tissue proliferation, lymphocyte and plasma cell infiltration, and acinar atrophy of the pancreas. Half of the patients showed a large number of IgG4 positive plasma cells as revealed by immunohistochemistry. Glucocorticoids were effective for IgG4-AIP, but 36.8% of the patients relapsed after remission, and 71.4% relapsed after stopping glucocorticoids. Logistic regression analysis showed that the risk factors for recurrence were pancreatic portal hypertension and involvement of extra-pancreatic organs. Low-dose glucocorticoid maintenance therapy could prevent recurrence.

CONCLUSION

Due to the lack of specific clinical manifestation, IgG4-AIP is easily misdiagnosed as pancreatic cancer. The main manifestations of IgG4-AIP are increased serum IgG4 level, diffuse or local swelling of pancreas with biliopancreatic duct stricture, multiple organ involvement, IgG4 positive plasma cell infiltration, tissue fibrosis, and response to treatment with glucocorticoids. The risk factors for recurrence of IgG4-AIP are pancreatic portal hypertension and extrapancreatic organ involvement. Low-dose glucocorticoid maintenance therapy can prevent recurrence.

Can IgG4-related disease present as isolated myositis?

IgG4-Related Disease (IgG4-RD)is a chronic fibroinflammatory disease typically characterized by inflammation or tumefaction of the organs involved. Skeletal muscle is not one of the typical organs involved in IgG4-RD. Isolated myositis related to IgG4-RD without common organ involvement such as lacrimal or salivary glands or retroperitoneal fibrosis is a controversial and debatable entity. Here we report a case of inflammatory myopathy in an elderly woman with several atypical clinical, lab, and histopathological findings suggestive of IgG4-related myositis. Two such case reports of IgG4-related myositis were reported in the literature review. This is a third case report of elevated IgG4 positive plasma cell infiltration in muscle with severe endomysial fibrosis and unusual myositis features (Figs. 1 and 2). This case-based review opens a possibility of a novel presentation of IgG4-RD and new pathogenesis in myositis.

Combined REGN-COV2 Antibody Therapy Immediately Prevented a Patient with Refractory Type 1 Autoimmune Pancreatitis from Contracting SARS-CoV-2 during the Sixth Wave in Japan

A 51-year-old man who had been receiving steroid therapy for type 1 autoimmune pancreatitis (AIP) for 3 years contracted coronavirus disease 2019 (COVID-19). As he had a high-grade fever and dry cough, and because his SpO2 level had dropped below 95% in the supine position, he was considered as being at a high risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); therefore, he received combined REGN-COV2 antibody therapy. The patient's fever resolved immediately after this treatment, and he went into remission. A high cumulative steroid dose is associated with an increased susceptibility to infection. Early antibody cocktail therapy may be effective and rewarding for steroid-dependent type 1 AIP patients with a potential risk for SARS-CoV-2.

IgG4-Related Disease Mimicking Unilateral Urothelial Carcinoma: A Rare Case Report and Literature Review

Immunoglobulin G4-related disease (IgG4-RD) is an autoimmune-mediated disorder with heterogeneous multiorgan manifestations. Early identification and treatment of IgG4-RD are crucial for organ function recovery. Rarely, IgG4-RD manifests as a unilateral renal pelvic soft tissue mass that may be misdiagnosed as urothelial malignancy, resulting in invasive surgical intervention and organ damage. Here we present a 73-year-old man who had a right ureteropelvic mass with hydronephrosis detected by enhanced computed tomography. Right upper tract urothelial carcinoma and lymph node metastasis was highly suggested based on the image findings. However, IgG4-RD was suspected due to his past history of bilateral submandibular lymphadenopathy, nasolacrimal duct obstruction, as well as a high serum IgG4 level of 861 mg/dL. The ureteroscopy with tissue biopsy showed no evidence of urothelial malignancy. His lesions and symptoms improved after glucocorticoid treatment. Hence, a diagnosis of IgG4-RD was made, with the phenotype of classic Mikulicz syndrome with systemic involvement. The manifestation of IgG4-RD as a unilateral renal pelvic mass is rare and should be kept in mind. A ureteroscopic biopsy and serum IgG4 level measurement can help in the diagnosis of IgG4-RD in patients with a unilateral renal pelvic lesion.

Pretherapy 18F-FDG PET/CT in Predicting Disease Relapse in Patients With Immunoglobulin G4-Related Disease: A Prospective Study

OBJECTIVE

To investigate whether the levels of inflammation detected by ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) can predict disease relapse in immunoglobulin G4-related disease (IgG4-RD) patients receiving standard induction steroid therapy.

MATERIALS AND METHODS

This prospective study analyzed pretherapy FDG PET/CT images from 48 patients (mean age, 63 ± 12.9 years; 45 males and 3 females) diagnosed with IgG4-RD between September 2008 and February 2018, who subsequently received standard induction steroid therapy as the first-line treatment. Multivariable Cox proportional hazards models were used to identify the potential prognostic factors associated with relapse-free survival (RFS).

RESULTS

The median follow-up time for the entire cohort was 1913 days (interquartile range [IQR], 803-2929 days). Relapse occurred in 81.3% (39/48) patients during the follow-up period. The median time to relapse was 210 days (IQR, 140-308 days) after completion of standardized induction steroid therapy. Among the 17 parameters analyzed, Cox proportional hazard analysis identified whole-body total lesion glycolysis (WTLG) > 600 on FDG-PET as an independent risk factor for disease relapse (median RFS, 175 vs. 308 days; adjusted hazard ratio, 2.196 [95% confidence interval: 1.080-4.374]; P = 0.030).

CONCLUSION

WTLG on pretherapy FDG PET/CT was the only significant factor associated with RFS in IgG-RD patients receiving standard steroid induction therapy.

Steroid therapy has an acceptable role as the initial treatment in autoimmune pancreatitis patients with pancreatic cyst formation: Based on a Japanese nationwide study

BACKGROUND

We attempted to determine the indications and limitations of steroid therapy as the first-line therapy in patients with autoimmune pancreatitis (AIP) with cyst formation (ACF).

METHODS

This Japanese multicenter survey was conducted to examine the merits/demerits of steroid treatment as the initial therapy for ACF.

RESULTS

Data of a total of 115 patients with ACF were analyzed. Complete remission was achieved in 86% (86/100) of patients who had received steroid treatment, but only 33.3% (5/15) of patients who had not received steroids. Relapse after the remission (n = 86) occurred in 7.6% (6/86) of patients who had received steroid therapy, but 40% (2/5) of patients who had not received steroid therapy. Multivariate analysis identified adoption of the wait and watch approach without steroid treatment (odds ratio = 0.126, P < .001) as a significant and independent negative predictor of remission of ACF. As for predictors of relapse, the presence of varix (odds ratio = 5.83, P = .036) was identified as an independent risk factor.

CONCLUSION

Steroid therapy plays an important role as first-line therapy in AIP patients with pancreatic cyst formation, however, varix formation, besides the diameter of the cyst(s), is a risk factor for refractoriness to steroid therapy.

Reducing relapse through maintenance steroid treatment can decrease the cancer risk in patients with IgG4-sclerosing cholangitis: Based on a Japanese nationwide study

OBJECTIVE

IgG4-related sclerosing cholangitis (IgG4-SC) is recognized as a benign steroid-responsive disease; however, little is known about the risk of development of cancer in patients with IgG4-SC and about how to counter this risk.

DESIGN

We conducted a retrospective review of the data of 924 patients with IgG4-SC selected from a Japanese nationwide survey. The incidence, type of malignancy, and risk of malignancy in these patients were examined. Then, the standardized incidence ratio (SIR) of cancer in patients with IgG4-SC was calculated.

RESULTS

Relapse was recognized in 19.7% (182/924) of patients, and cancer development was noted in 15% (139/924) of patients. Multivariate analysis identified only relapse as an independent risk factor for the development of cancer. In most of these patients with pancreato-biliary cancer, the cancer developed within 8 years after the diagnosis of IgG4-SC. The SIR for cancer after the diagnosis of IgG4-SC was 12.68 (95% confidence interval [CI] 6.89-8.79). The SIRs of cancers involving the biliary system and pancreas were 27.35 and 18.43, respectively. The cumulative survival rate was significantly better in the group that received maintenance steroid treatment (MST) than in the group that did not; thus, MST influenced the prognosis of these patients.

CONCLUSION

Among the cancers, the risk of pancreatic and biliary cancers is the highest in these patients. Because of the elevated cancer risk, surveillance after the diagnosis and management to prevent relapse are important in patients with IgG4-SC to reduce the risk of development of cancer.

Development of targeted therapies in IgG4-related disease

IgG4-related disease (IgG4-RD) is a systemic disease characterized by high serum IgG4 levels, infiltration of lymphocytes and IgG4-positive plasma cells into affected tissues, and subsequent fibrosis, forming mass, nodular, and thickened lesions in organs. Although glucocorticoids (GCs) are the first-line treatment for IgG4-RD, the disease often relapses during dose reduction or after discontinuation of GC. Long-term treatment with GC is associated with adverse effects such as infection, osteoporosis, and atherosclerosis. Therefore, there is an urgent need to develop a treatment strategy that specifically addresses the pathogenesis of IgG4-RD. As immunocompetent cells and immune-related molecules involved in the pathogenesis of IgG4-RD are increasingly being identified, there is a growing demand for new molecular-targeted drugs that target them. In particular, favourable results have been reported for drugs that target B cells, such as anti-cluster of differentiation (CD)20 and anti-CD19 antibodies. In addition, clinical trials are underway for new therapeutic agents, such as anti-signalling lymphocytic activation molecule family 7 antibodies that target T cells and other cells.

Perspectives on current and emerging therapies for immunoglobulin G4-related disease

Understanding of the pathophysiology of immunoglobulin G4-related disease (IgG4-RD) over the last dozen years has opened the door to a variety of targeted treatment approaches. Glucocorticoids are an effective treatment for IgG4-RD if used at a sufficiently high dose, but disease flares are common during or after glucocorticoid tapers and these medications seldom lead to long-term, treatment-free remissions. Moreover, their long-term use in a disease that frequently affects middle-aged to elderly individuals and often causes major pancreatic damage leads to a narrow therapeutic index. Biological therapies offer the possibility of effective disease control with fewer treatment-associated side effects. Promising avenues of investigation include B-cell depletion, immunomodulation of B-cell subsets, interference with co-stimulation, Bruton's tyrosine kinase inhibition, and Signaling lymphocytic activation molecule F7-directed treatment.

Glucocorticoids in the treatment of IgG4-related disease-Prospects for new international treatment guidelines

Immunoglobulin G4-related disease (IgG4-RD) is a chronic fibro-inflammatory disease that may cause dysfunction in various organs. Worldwide multidisciplinary experts attending the Fourth International Symposium on IgG4-Related Disease in Japan in 2021 discussed treatments for IgG4-RD, especially glucocorticoid (GC) therapy. This review describes the efficacy, safety, and cost of treatments for IgG4-RD based on findings presented at the international symposium. A medium dose of GC was considered appropriate for the initial treatment of IgG4-RD. A randomized controlled trial and an open-label prospective study have shown that long-term maintenance GC therapy (prednisolone ≥ 5 mg/day) could prevent disease relapse. In addition, two open-label randomized controlled trials reported the effects of combinational use of GC and synthetic immunosuppressive agents, mycophenolate mofetil and leflunomide, on relapse prevention. Moreover, an open-label single-arm study showed an excellent rate of clinical response to rituximab. Many observational studies have shown the efficacy of an appropriate GC regimen in patients with IgG4-RD. Synthetic immunosuppressive agents and a molecular-targeted agent can be potent alternatives to GCs, but additional studies are required comparing their efficacy, risk of infection, and costs.

IgG4-related autoimmune liver disease

The term IgG4-related autoimmune liver disease (AILD) refers to hepato-biliary manifestations of Immunoglobin G4-related disease (IgG4-RD) including IgG4-related sclerosing cholangitis and IgG4-related pseudotumor. The association of some forms of autoimmune hepatitis to IgG4-RD remains controversial. Although autoimmune phenomena have not been clearly observed in IgG4-AILD, perturbation of the adaptive immune system and activation of the humoral response represent established pathophysiological hallmarks and potential therapeutic targets. Clinical manifestations of IgG4-AILD are virtually indistinguishable from bile duct cancer or primary sclerosing cholangitis and are due to mass forming lesions and thickening of the biliary tract that progressively lead to biliary ducts obstruction. There are no current reliable biomarkers for IgG4-AILD and diagnosis should rely on the integration of clinical, serological, radiological, and histological findings. In analogy to most IgG4-RD manifestations, and in contrast to its major mimickers, IgG4-AILD promptly responds to glucocorticoids but frequently relapses, thus requiring long-term maintenance therapy to avoid progressive fibrosclerotic disease and liver cirrhosis. Accumulating evidence on the efficacy of B-cell depletion therapy in patients with systemic IgG4-RD is gradually changing the treatment paradigm of IgG4-AILD and biologics will be increasingly used also for gastroenterological manifestations of IgG4-RD to spare glucocorticoids and traditional immunosuppressive agents. Looking ahead, identification of reliable biomarkers and of mini-invasive strategies to obtain informative biopsies from the biliary tree represent unavoidable priorities to optimize diagnosis and management of IgG4-AILD.

Comparison of the efficacy and safety of leflunomide versus mycophenolate mofetil in treating IgG4-related disease: a retrospective cohort study

OBJECTIVE

Combination therapy of glucocorticoids (GCs) plus leflunomide (LEF) and GCs plus mycophenolate mofetil (MMF) was reported to have good efficacy and safety in the management of IgG4-RD. However, studies comparing the efficacy and safety of these two combination therapies were unavailable. Herein, this study aimed to compare the efficacy and safety of GCs plus LEF and GCs plus MMF in treating IgG4-RD.

METHODS

This study included 130 newly diagnosed IgG4-RD patients who received the therapy of GCs plus LEF (group I) and GCs plus MMF (group II). Clinical data at baseline and after treatment, treatment response, relapse rate, and adverse effects were recorded and analyzed.

RESULTS

Patients in both groups responded well to the treatment in the 1st-month follow-up, and 100% of patients achieved treatment response. However, at the 6th and 12th-month follow-up, the total response rate of group II was higher than that in group I (75.6 vs. 53.7%, p = 0.038 and 85.4% vs. 61.0%, p = 0.013, respectively). In addition, the duration of disease remission in group II was longer than that in group I (9 (6-9) vs. 6 (6-6) months, p = 0.014). Moreover, more patients in group I had adverse effects compared with group II (36.6 vs. 7.3%, p < 0.01); and the most common adverse events of LEF were rash (12.2%) and elevation of liver enzymes (9.8%).

CONCLUSION

The combination therapy of GCs plus low-dose MMF had better efficacy and safety in the management of IgG4-RD compared with the therapy of GCs plus LEF.

Autoimmune pancreatitis with IgG-4 cholangiopathy in a pregnant woman: A case report

Diagnosis and management of autoimmune pancreatitis during pregnancy. Autoimmune pancreatitis is a rare and life-threatening condition with increased maternal and fetal morbidity and mortality. Autoimmune pancreatitis may result in a mass-forming lesion in the pancreas resembling pancreatic cancer; therefore, meticulous and careful investigations must be done to avoid misdiagnosing autoimmune pancreatitis as pancreatic cancer. Since autoimmune pancreatitis improves dramatically to steroid therapy, accurate diagnosis of autoimmune pancreatitis can avoid unnecessary procedures, surgeries, and pancreatic resection. A case of a pregnant lady in her third trimester was presented with abdominal pain, nausea, and vomiting. On examination, there was tenderness in both epigastric and right hypochondrium associated with elevated serum amylase, liver transaminases, alkaline phosphatase, gamma-glutamyl transpeptidase, and immunoglobulin G4. Both abdominal ultrasound and magnetic resonance cholangiopancreatography showed a pancreatic head lesion with dilation in both pancreatic duct and common bile duct. Steroid was initiated that resulted in rapid and dramatic responsiveness. Acute pancreatitis is uncommon during pregnancy, and autoimmune pancreatitis is a very rare form of acute pancreatitis; therefore, a clear and rapid assessment, diagnosis, and management plan are necessary to avoid maternal and fetal morbidity and mortality.