Immune checkpoint inhibitor-related nephrotoxicity: Pembrolizumab-induced acute interstitial nephritis

Pembrolizumab, an immune checkpoint inhibitor targeting Programmed Cell Death-1 (PD-1), has transformed the treatment landscape for various malignancies. While its efficacy is well-documented, immune-related adverse events (irAEs), including renal toxicities, are emerging concerns. This case series presents three patients who developed significant renal complications, specifically acute interstitial nephritis (AIN) and distal renal tubular acidosis (RTA), following pembrolizumab therapy. Case 1 involved a 40-year-old male with non-Hodgkin’s lymphoma who developed AIN and distal RTA seven months post-therapy, responding well to corticosteroids and supportive care. Case 2 described a 61-year-old female with triple-negative breast cancer who developed AIN during active treatment, requiring dialysis and prolonged corticosteroid therapy. Case 3 involved a 65-year-old male with metastatic non–small cell lung cancer who developed AIN three months after initiation of pembrolizumab and showed gradual recovery with high-dose corticosteroids. These three cases highlight the importance of vigilant renal monitoring in patients receiving pembrolizumab and the need for awareness of potential renal irAEs. • Immune-Related Adverse Event s: Pembrolizumab therapy can lead to significant renal complications, including acute interstitial nephritis (AIN) and distal renal tubular acidosis (RTA). • Clinical Management: Corticosteroids and supportive care were effective in managing AIN and RTA in a non-Hodgkin’s lymphoma patient, while a triple-negative breast cancer patient required dialysis and prolonged corticosteroid therapy. • Practice Implications: Vigilant renal monitoring and heightened awareness of renal toxicities are essential in patients undergoing pembrolizumab treatment to improve clinical outcomes.