Acute kidney injury in patients receiving immune checkpoint inhibitors: a retrospective real-world study

Background: Immune checkpoint inhibitors (ICPi) can cause immune-related adverse events (irAEs) including acute kidney injury (AKI). We investigated the incidence of ICPi-associated AKI (ICPi-AKI) and AKI from other causes (non-ICPi-AKI) in cancer patients treated with ICPi.

Methods: This was a single-centre retrospective cohort study of patients receiving ICPi therapy between December 2011 and August 2020. AKI was defined and staged by the Kidney Disease Improving Global Outcomes creatinine criteria. The primary outcome was the incidence of AKI and ICPi-AKI.

Results: A total of 1037 patients were included in the final analysis. The median age was 63 years, 60% were male, and 22% had pre-existing chronic kidney disease. Overall, 189 patients (18.2%) developed AKI of whom 37 patients (3.6%) had ICPi-AKI. In patients with progressive cancer, AKI was not associated with increased mortality. In treatment responders, non-ICPi-AKI was associated with an increased risk of mortality (adjusted hazard ratio [HR] 2.03; 95% confidence interval [CI] 1.12-3.67), whereas ICPi-AKI was not linked to an increased risk of death (adjusted HR 0.60; 95% CI 0.18-1.96). Patients with ICPi-AKI were more likely to have higher AKI stages and less likely to have complete kidney recovery compared with non-ICPi-AKI (54% versus 79%, p = 0.01).

Conclusion: AKI was common in cancer patients treated with ICPi. Patients with ICPi-AKI had worse kidney outcomes compared to those with AKI from other causes. However, non-ICPi-AKI was associated with a higher risk of death. These findings emphasise the importance of identifying different sub-phenotypes of AKI.