Table 5.

Proposed definition and classification of immune checkpoint inhibitor–associated AKI

Classification	Definition
Definite ICPI-AKI	Kidney biopsy confirmed diagnosis compatible with ICPI-AKI, and after clinical review of risk factorsa
Probable ICPI-AKI	BOTH of the following Sustained increase in SCr ≥50% on at least two consecutive values or need for RRT, after clinical review of risk factorsaAbsence of an alternative plausible etiology AND at least one of the following Sterile pyuria (≥5 WBCs/hpf) Concomitant or recent extrarenal irAEEosinophilia (≥500 cells per µl)
Possible ICPI-AKI	BOTH of the following Increase in SCr ≥50% or need for RRTAKI is not readily attributable to alternative causes

ICPI-AKI, immune checkpoint inhibitor–associated AKI; SCr, serum creatinine; WBC, white blood cell; hpf, high-power field; irAE, immune-related adverse event.

^aRisk factors include prior or concomitant proton pump inhibitor use, prior or concomitant extrarenal irAEs.