Efficacy and safety of rituximab in autoimmune pancreatitis type 1: our experiences and systematic review of the literature

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.

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.

Treatment approaches in autoimmune pancreatitis (Review)

Autoimmune pancreatitis (AIP) is a rare disease. There are two distinct types of AIP: AIP type 1 (AIP-1), a pancreatic manifestation of a multi-organ disease linked to immunoglobulin (Ig)G4, and AIP type 2 (AIP-2), a pancreas-specific disease unrelated to IgG4. The usual course of treatment for AIP is oral corticosteroid medication. Rituximab has also been recommended for recurrent AIP-1 in order to initiate remission and provide ongoing treatment. Immunomodulators such as azathioprine are used to keep certain patients in remission. Evaluation also takes into account a number of pharmacological alternatives, including biologic drugs like anti-tumor necrosis factor therapy, a safe and efficient second-line treatment for AIP-2 relapse or steroid dependence. Corticosteroids and immunosuppressants, which are poorly tolerated due to considerable side effects, are being replaced by other biologic drugs, which may offer a beneficial therapeutic alternative.

Autoimmune Pancreatitis Type 1 with Biliary, Nasal, Testicular, and Pulmonary Involvement: A Case Report and a Systematic Review

INTRODUCTION

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated condition associated with fibroinflammatory lesions that can occur at almost any anatomical site. It often presents as a multiorgan disease that may mimic malignancy, infection, or other immune-mediated conditions. Autoimmune pancreatitis (AIP) type 1 is the most prominent manifestation of IgG4-RD in the digestive tract, with common extra-pancreatic inflammation. We present the first patient with AIP and involvement of the testicles and nasal cavity.

PATIENT AND METHODS

A case of a patient with AIP type 1 and other organ involvement (bile ducts, testicles, nasal polyps, and lungs) is described. Additionally, a systematic review of AIP type 1 with testicular and nasal involvement was conducted.

RESULTS

The systematic review found two cases of AIP type 1 with testicular involvement and 143 cases with AIP type 1 with nasal cavity involvement. None of them had both testicular and nasal involvement.

CONCLUSIONS

This is the first case of AIP type 1 with other organ involvement, including testicular and nasal involvement, to be described. The number of patients with nasal and testicular involvement described in the literature is low. Creating awareness of this rare clinical condition is necessary, especially due to the very effective available treatment with corticosteroids and rituximab.

Autoimmune pancreatitis associated with inflammatory bowel diseases: A retrospectively bidirectional case-control study in China

OBJECTIVES

Autoimmune pancreatitis (AIP) is a rare and enigmatic immune-mediated inflammatory disease. We aimed to investigate the prevalence, characteristics, and associated factors of AIP-inflammatory bowel disease (IBD) in China.

METHODS

A retrospective bidirectional case-control study was performed. The diagnoses of IBD and AIP were made based on the European Crohn's and Colitis Organization guidelines and the International Consensus Diagnostic Criteria. IBD controls were matched by age, sex, and IBD type at a ratio of 1:4, while AIP controls were matched by AIP types.

RESULTS

The age-standardized prevalence of AIP-IBD patients in the IBD and AIP population were 292.0 and 8151.93 per 100 000 population, respectively. IBD patients had a higher risk of AIP compared to non-IBD patients (odds ratio 8.4, 95% confidence interval 4.7-14.9, P < 0.0001), and AIP patients had a higher risk of developing IBD compared to the general population in China. The mean age at diagnosis of IBD and AIP was 34.83 years and 40.42 years. IBD was diagnosed before AIP in seven cases. The median total IBD and AIP duration was 43.5 months and 13.5 months. Use of mesalamine and tuberculosis were associated with AIP in IBD patients (P = 0.031). And fecal occult blood test was associated with IBD in AIP patients (P = 0.008).

CONCLUSIONS

Most AIP-IBD patients had ulcerative colitis and type 2 AIP. IBD patients are more likely to develop AIP compared to the general population, and vice versa. Use of mesalamine and tuberculosis infection were associated with AIP, and fecal occult blood test was associated with IBD.

Recent progress on the treatment of type 1 autoimmune pancreatitis and IgG4-related disease

IgG4-related disease (IgG4-RD) is a fibroinflammatory disorder recognized as a novel clinical entity with either synchronous or metachronous multiorgan involvement. Autoimmune pancreatitis (AIP) is classified into two types: type 1 AIP as a pancreatic manifestation of IgG4-RD and type 2 AIP with granulocytic epithelial lesion and occasional association with ulcerative colitis. Although the pathogenic mechanism still remains unclear, possible multipathogenic factors such as genetic factors, disease-specific or related antigens, and abnormal innate or adaptive immunity may be involved in the development of IgG4-RD. Many immunocytes including M2 macrophages, plasmablasts, 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 induction and maintenance therapies with glucocorticoid or rituximab are recommended in all symptomatic patients with active IgG4-RD. In those at risk for irreversible damage in any organs, this should be done urgently, regardless of symptoms. As no randomized clinical trials other than glucocorticoid maintenance therapy for type 1 AIP have been performed, 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.

Autoimmune Pancreatitis: From Pathogenesis to Treatment

Autoimmune pancreatitis (AIP) is a rare disease. The diagnosis of AIP is difficult and should be made by a comprehensive evaluation of clinical, radiological, serological, and pathological findings. Two different types of AIP have been identified: autoimmune pancreatitis type 1 (AIP-1), which is considered a pancreatic manifestation of multiorgan disease related to IgG4, and autoimmune pancreatitis type 2 (AIP-2), which is considered a pancreas-specific disease not related to IgG4. Although the pathophysiological conditions seem to differ between type 1 and type 2 pancreatitis, both respond well to steroid medications. In this review, we focused on the pathogenesis of the disease to develop a tool that could facilitate diagnosis and lead to the discovery of new therapeutic strategies to combat autoimmune pancreatitis and its relapses. The standard therapy for AIP is oral administration of corticosteroids. Rituximab (RTX) has also been proposed for induction of remission and maintenance therapy in relapsing AIP-1. In selected patients, immunomodulators such as azathioprine are used to maintain remission. The strength of this review, compared with previous studies, is that it focuses on the clear difference between the two types of autoimmune pancreatitis with a clearly delineated and separate pathogenesis. In addition, the review also considers various therapeutic options, including biologic drugs, such as anti-tumor necrosis factor (TNF) therapy, a well-tolerated and effective second-line therapy for AIP type 2 relapses or steroid dependence. Other biologic therapies are also being explored that could provide a useful therapeutic alternative to corticosteroids and immunosuppressants, which are poorly tolerated due to significant side effects.

Therapy of immunoglonuline IgG4 related disease (IgG4-RD)

Immunoglobulin IgG4 related disease (IgG4-RD) is a heterogeneous disorder with multi-organ involvement recognised as a separate entity at the beginning of this century only. Evolving therapy is reviewed in this paper. Glucocorticoids are first choice drug but long administration of glucocorticoids is connected with many adverse effects. In case of combination glucocorticoids and immunosuppressive agents lower doses of glucocorticoids are needed, the response rate is higher and therapy is better tolerated. Rituximab is drug, that is possible use as monotherapy or in combination with glucocorticoids and immunosuppressive drugs. Only one study compared two immunosuporessive drugs, mycophenolate mofetil and cyclophosphamide. The response rated was similar but remissions were longer after glucocorticoids with cyclophosphamide then glucocorticoids with mycofenolat mofetil. No other comparative study of combination of various imunossupressive drugs with glucocorticoids was published. Rituximab has high number (90 %) of response rate in monotherapy, but can be used in combination with glucocorticoids and immunosuppressives. Rituximab is now preferred and recommended for maintenance therapy administered in 6-month interval. In case of advanced disease, we prefer therefore combination of rituximab, cyclofosphamide and dexamethasone for initial therapy followed by maintenance with rituximab in 6 months interval. There are two new drugs under investigation abatacept and dupilimab with promising results. Although we have very intensive therapies for good results of therapy early diagnosis before irreversible fibrotic changes in IgG4-RD involved organs is still needed.