ANCA-negative pauci-immune crescentic glomerulonephritis associated with nivolumab in lung cancer.

Immune checkpoint inhibitors (ICIs) have substantially improved the prognosis of many cancer patients but are also associated with various immune-related adverse events (irAEs). Kidney irAEs are relatively rare, with acute tubulointerstitial nephritis being the most common manifestation. However, some patients develop ICIs-associated glomerular diseases, including pauci-immune crescentic glomerulonephritis. In this report, we present the case of a 72-year-old man with lung squamous cell carcinoma treated with nivolumab, a monoclonal antibody targeting programmed cell death 1 (PD-1). The patient developed rapidly progressive glomerulonephritis a few weeks after initiating nivolumab therapy. Immunological tests yielded negative results, and a kidney biopsy revealed pauci-immune crescentic glomerulonephritis. Immunohistological examination confirmed programmed death ligand-1 (PD-L1) expression in the glomeruli. Despite intensive therapy, including corticosteroid pulse treatment, the patient's kidney function did not recover, necessitating maintenance hemodialysis. This is the first report demonstrating PD-L1 staining in injured glomeruli caused by anti-PD-1 therapy. Immunohistochemistry for PD-L1 may aid in diagnosing glomerulonephritis related to anti-PD-1 therapy.