Impact of Immune Checkpoint Inhibitors on AKI Incidence and Mortality in Patients with Bladder Cancer: A Single-Center Experience

Background: Immune checkpoint inhibitors (ICPi) have increasingly become a therapeutic option for bladder cancer. Among bladder cancer patients, ICPi-associated acute kidney injury (AKI) has emerged as a significant toxicity. This study aims to describe the incidence, risk factors, renal outcomes, and mortality of AKI in patients receiving ICPi. Methods: Patients who received ICPi between January 2021 and December 2021 at a single institution were retrospectively identified using the electronic medical database. AKI was defined as an increase in serum creatinine of ≥1.5 times the baseline value, based on the Kidney Disease: Improving Global Outcomes criteria. Cox proportional hazard regression analysis was used to assess risk factors for AKI and to evaluate the relationship between AKI and mortality. Results: Among 108 patients with bladder cancer receiving checkpoint inhibitors, the overall incidence of AKI was 55.6%. Half of all AKI cases were associated with checkpoint inhibitors. Checkpoint inhibitor-associated AKI was mostly low-grade and occurred a median of 2 months after initiating the checkpoint inhibitors. AKI stage, the period from ICPi initiation to AKI occurrence, and the use of H2 blockers differed significantly between the non-ICPi AKI group and the ICPi-AKI group. However, the presence of all-cause AKI or checkpoint inhibitor-associated AKI did not lead to increased mortality. Conclusion: This study shows that AKI frequently occurs in bladder cancer patients receiving ICPi. However, the presence of all-cause AKI and AKI related to ICPi toxicity did not increase mortality in these patients. Cox proportional hazard regression analysis of relationship between AKI group and mortality. - Crude Adjusted HR (95%CI) HR (95%CI) No AKI Reference Reference AKI development 55.2(0.25 - 1217) 0.91 (0.80-1.04) ICPi related AKI 2.52 (0.67 - 9.39) 0.27 (0.05 - 1.42) Non ICPi related AKI 2.94 (0.79 - 11.0) 3.06 (0.70 - 18.5)