Immune Checkpoint Inhibitor-Associated Acute Kidney Injury: A Single-Centre Study

Immune checkpoint inhibitors (ICIs) have improved cancer outcomes but can cause immune-related adverse effects (irAEs), including acute kidney injury (AKI). Limited Australian data exists regarding ICI-associated AKI (ICI-AKI). This observational study is aimed to describe the incidence, risk factors, and outcomes of ICI-AKI at Southern Adelaide Local Health Network (SALHN), South Australia.

Adult patients receiving ICI therapy at SALHN between January 2020 and December 2023 were included. Clinical and laboratory data were collected from electronic medical records. ICI-AKI was defined as AKI that led to the delay or discontinuation of ICI therapy due to clinical concern, biopsy-proven ICI-related tubulointerstitial nephritis, or corticosteroid-treated suspected ICI-AKI. Data on kidney biopsy findings, corticosteroid use, ICI rechallenge, AKI recurrence, and renal recovery were assessed.

Among 507 patients, 58 (11.4%) developed AKI, with 11 cases (2.2%) attributed to ICIs. Ipilimumab use and lower baseline eGFR were associated with higher AKI and ICI-AKI risk, while durvalumab was associated with lower AKI risk. Median time to AKI onset was 83 days post-first ICI cycle. Corticosteroids were initiated in eight patients for a median of 154 days. Four patients underwent kidney biopsy (median 106 days post-AKI), all showing tubulointerstitial nephritis. Four patients were rechallenged with ICIs; one had recurrent AKI. One patient required dialysis, and two achieved complete renal recovery.

In this first Australian study examining all forms of cancer, ICI-AKI occurred infrequently, but had a significant clinical impact. Ipilimumab exposure and impaired baseline kidney function were key risk factors.