Differentiating Acute Interstitial Nephritis From Immune Checkpoint Inhibitors From Other Causes

Abstract

Immune checkpoint inhibitors (ICIs) have significantly improved outcomes for patients with neoplasms in advanced stages. On the other hand, ICIs have immune-related adverse events. These adverse events affect mostly other organs than the kidney, such as skin or gastrointestinal tract. The incidence of nephrotoxicity with monotherapy with any ICI is about 2%, which increases to 5% in combination therapy. Acute tubulointerstitial nephritis (AIN) is the most common pattern of kidney damage related to ICIs. Globally, without considering ICI nephrotoxicity, AIN is estimated to account for 15% to 20% of cases of acute kidney injury (AKI). This is crucial because patients who are treated with ICIs, may also be taking other drugs that potentially cause AIN, and therefore, knowing the particularities about ICI-related AIN could be helpful in clinical practice to better understand the phenotypic differences between the 2 types of AIN. In addition, several studies have now shown that being on proton pump inhibitors is a risk factor for AIN from ICI therapy.