Clinical presentation of PD-1/PD-L1 immune checkpoint inhibitors induced cystitis.

This study aims to systematically analyze the clinical features of cystitis induced by anti-PD-1/PD-L1 drugs, with a view to providing a basis for early warning, diagnosis, and standardized management of this adverse reaction in clinical practice. In this study, we comprehensively searched multiple databases to systematically collect all case reports involving cystitis induced by anti-PD-1/PD-L1 drugs from the initiation of relevant research up to May 20, 2025, and conducted an in-depth retrospective analysis of these cases. The clinical characteristics of 43 patients with cystitis induced by anti-PD-1/PD-L1 agents in this study showed a median age of 57 years (27-78 years), with 26 cases (60.5%) being male. The median time from the initiation of these agents to cystitis onset was 96 days (9-510 days). Diagnosis confirmed that 81.4% cases were non-infectious cystitis, and antibiotic treatment was often ineffective or showed suboptimal efficacy. After discontinuing the relevant drugs and administering appropriate steroids, patients generally had a favorable prognosis. Notably, reinitiating anti-PD-1/PD-L1 therapy was associated with a significantly increased risk of cystitis recurrence. Cystitis is a rare adverse reaction during PD-1/PD-L1 immune checkpoint inhibitor therapy, which can impact patients' quality of life. It is notable that nearly all cases can be effectively managed through timely intervention and standardized pharmacotherapy. Therefore, early identification of cystitis induced by these drugs and the implementation of appropriate management strategies are crucial for improving patient outcomes.