Clinical Characteristics and Outcomes of Immune Checkpoint Inhibitor Associated Renal Toxicities: A Retrospective Pan-Cancer Cohort Study.

The mechanism of immune checkpoint inhibitors lead to off-target inflammation that results in a broad spectrum of toxicities. The aim of this study was evaluate risk factors, management, and outcomes of immune checkpoint inhibitor-related nephritis. We performed a retrospective review of 2,723 patients treated with ICIs (2015-2024) at a tertiary center. Patients who developed immune-mediated nephritis were identified and analyzed for demographics, cancer type, treatment, nephritis severity (ASCO grading), and outcomes. Fisher's exact tests assessed associations with renal cell carcinoma (RCC) and baseline chronic kidney disease (CKD). Thirty-seven patients (1.36%) developed ICI-related nephritis, with a median onset at 16.5 weeks. RCC was associated with a higher risk (OR: 5.9, p < 0.001), while baseline CKD was not associated with increased severity of ICI nephritis. Most patients (65%) did not recover renal function despite holding ICIs. Among those treated with steroids, 62% were refractory. Rechallenge led to recurrent AKI in 78% of patients, and nearly one-third transitioned to hospice. ICI-related nephritis is rare but associated with poor renal recovery and high recurrence on rechallenge. Improved risk stratification and optimization of management strategies are needed.