BackgroundDespite increasing recognition of the importance of immune checkpoint inhibitor–associated AKI, data on this complication of immunotherapy are sparse.MethodsWe conducted a multicenter study of 138 patients with immune checkpoint inhibitor–associated AKI, defined as a ≥2-fold increase in serum creatinine or new dialysis requirement directly attributed to an immune checkpoint inhibitor. We also collected data on 276 control patients who received these drugs but did not develop AKI.ResultsLower baseline eGFR, proton pump inhibitor use, and combination immune checkpoint inhibitor therapy were each independently associated with an increased risk of immune checkpoint inhibitor–associated AKI. Median (interquartile range) time from immune checkpoint inhibitor initiation to AKI was 14 (6–37) weeks. Most patients had subnephrotic proteinuria, and approximately half had pyuria. Extrarenal immune-related adverse events occurred in 43% of patients; 69% were concurrently receiving a potential tubulointerstitial nephritis–causing medication. Tubulointerstitial nephritis was the dominant lesion in 93% of the 60 patients biopsied. Most patients (86%) were treated with steroids. Complete, partial, or no kidney recovery occurred in 40%, 45%, and 15% of patients, respectively. Concomitant extrarenal immune-related adverse events were associated with worse renal prognosis, whereas concomitant tubulointerstitial nephritis–causing medications and treatment with steroids were each associated with improved renal prognosis. Failure to achieve kidney recovery after immune checkpoint inhibitor–associated AKI was independently associated with higher mortality. Immune checkpoint inhibitor rechallenge occurred in 22% of patients, of whom 23% developed recurrent associated AKI.ConclusionsThis multicenter study identifies insights into the risk factors, clinical features, histopathologic findings, and renal and overall outcomes in patients with immune checkpoint inhibitor–associated AKI.

Rationale & ObjectiveThe approved therapeutic indication for immune checkpoint inhibitors (CPIs) are rapidly expanding including treatment in the adjuvant setting, the immune related toxicities associated with CPI can limit the efficacy of these agents. The literature on the nephrotoxicity of CPI is limited. Here, we present cases of biopsy proven acute tubulointerstitial nephritis (ATIN) and glomerulonephritis (GN) induced by CPIs and discuss potential mechanisms of these adverse effects.Study design, setting, & participantsWe retrospectively reviewed all cancer patients from 2008 to 2018 who were treated with a CPI and subsequently underwent a kidney biopsy at The University of Texas MD Anderson Cancer Center.ResultsWe identified 16 cases diagnosed with advanced solid or hematologic malignancy; 12 patients were male, and the median age was 64 (range 38 to 77 years). The median time to developing acute kidney injury (AKI) from starting CPIs was 14 weeks (range 6–56 weeks). The average time from AKI diagnosis to obtaining renal biopsy was 16 days (range from 1 to 46 days). Fifteen cases occurred post anti-PD-1based therapy. ATIN was the most common pathologic finding on biopsy (14 of 16) and presented in almost all cases as either the major microscopic finding or as a mild form of interstitial inflammation in association with other glomerular pathologies (pauci-immune glomerulonephritis, membranous glomerulonephritis, C3 glomerulonephritis, immunoglobulin A (IgA) nephropathy, or amyloid A (AA) amyloidosis). CPIs were discontinued in 15 out of 16 cases. Steroids and further immunosuppression were used in most cases as indicated for treatment of ATIN and glomerulonephritis (14 of 16), with the majority achieving complete to partial renal recovery.ConclusionsOur data demonstrate that CPI related AKI occurs relatively late after CPI therapy. Our biopsy data demonstrate that ATIN is the most common pathological finding; however it can frequently co-occur with other glomerular pathologies, which may require immune suppressive therapy beyond corticosteroids. In the lack of predictive blood or urine biomarker, we recommend obtaining kidney biopsy for CPI related AKI.

BackgroundImmune checkpoint inhibitor-associated acute kidney injury (ICPi-AKI) has emerged as an important toxicity among patients with cancer.MethodsWe collected data on 429 patients with ICPi-AKI and 429 control patients who received ICPis contemporaneously but who did not develop ICPi-AKI from 30 sites in 10 countries. Multivariable logistic regression was used to identify predictors of ICPi-AKI and its recovery. A multivariable Cox model was used to estimate the effect of ICPi rechallenge versus no rechallenge on survival following ICPi-AKI.ResultsICPi-AKI occurred at a median of 16 weeks (IQR 8–32) following ICPi initiation. Lower baseline estimated glomerular filtration rate, proton pump inhibitor (PPI) use, and extrarenal immune-related adverse events (irAEs) were each associated with a higher risk of ICPi-AKI. Acute tubulointerstitial nephritis was the most common lesion on kidney biopsy (125/151 biopsied patients [82.7%]). Renal recovery occurred in 276 patients (64.3%) at a median of 7 weeks (IQR 3–10) following ICPi-AKI. Treatment with corticosteroids within 14 days following ICPi-AKI diagnosis was associated with higher odds of renal recovery (adjusted OR 2.64; 95% CI 1.58 to 4.41). Among patients treated with corticosteroids, early initiation of corticosteroids (within 3 days of ICPi-AKI) was associated with a higher odds of renal recovery compared with later initiation (more than 3 days following ICPi-AKI) (adjusted OR 2.09; 95% CI 1.16 to 3.79). Of 121 patients rechallenged, 20 (16.5%) developed recurrent ICPi-AKI. There was no difference in survival among patients rechallenged versus those not rechallenged following ICPi-AKI.ConclusionsPatients who developed ICPi-AKI were more likely to have impaired renal function at baseline, use a PPI, and have extrarenal irAEs. Two-thirds of patients had renal recovery following ICPi-AKI. Treatment with corticosteroids was associated with improved renal recovery.

Background:The incidence of renal immune-related adverse events (irAEs) is reported to be 3.8%, with varied definitions of acute kidney injury (AKI). This study reports a 10-year experience at MD Anderson Cancer Center of patients diagnosed with melanoma and treated with immune checkpoint inhibitors (ICIs) and evaluated the incidence of AKI, associated factors, and its association with overall survival. Methods: A retrospective chart review (2010-2019) of all patients with melanoma treated with ipilimumab, nivolumab, pembrolizumab, or atezolizumab was performed. All available serum creatinine data were extracted and used to calculate the estimated GFR (eGFR) using the CKD Epi equation, and to diagnose AKI using the two KDIGO (Kidney Disease: Improving Global Outcomes) criteria for defining stage I AKI in 1664 unique patients. Cumulative incidence rates of AKI after initiation of ICIs were calculated in the presence of death as a competing risk. The effects of covariates on the cumulative incidence function of AKI were evaluated in a univariant and multivariable analysis. Overall survival was estimated by Kaplan-Meier method in accordance to the occurrence of AKI. Results: The incidence of AKI by definitions 1a and 1b were 3.49% and 3.33%, respectively. After adjudication, AKI attributable to ICI was 58% and 65% of the overall incidence of AKI in each definition respectively. Increasing age was associated with decreased risk of AKI. Asian race was associated with a higher risk of AKI. Comorbidities were not associated with increased risk of AKI while use of proton pump inhibitors (PPI), ipilimumab or ICI combinations were significantly associated with AKI. AKI was not significantly associated with overall survival.Immune-related adverse events (irAEs) occurred in 30% of patients with AKI but their incidence was not different in patients with AKI attributable to ICI versus other AKI. Conclusions: In a large population of patients with melanoma treated with ICIs, an accurate documentation of AKI in setting of ICI use and predictors associated is presented. AKI following ICI use is infrequent, not associated with mortality, and associated with the use of ipilimumab, ICI combinations and PPIs.