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. I 2% 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%), I 2 =53%, respectively. The pooled relapse rate was 23% (13% to 36%), I 2=64%. The pooled rate of total adverse events was 21% (12% to 35%), I 2=52%. The pooled partial remission rate is 16% (7% to 32%), I 2=25%. The pooled rate of complete and partial remission was 81% (66% to 90%), I 2=75%. The pooled infusion reaction and infection were 12% (7% to 18%), I 2=0% and 14% (8% to 22%), I 2=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.