Anti-GBM glomerulonephritis in a patient with lung adenocarcinoma following pembrolizumab therapy.

Anti-glomerular basement membrane (anti-GBM) disease is a rare, life-threatening small vessel vasculitis affecting the kidneys and lungs, caused by autoantibodies against type IV collagen. Immune checkpoint inhibitors (ICIs) are an oncology treatment that block suppressive molecules on antitumour T lymphocytes, encouraging the immune system to attack cancerous cells. We report the case of a man in his 60s receiving the ICI pembrolizumab for lung adenocarcinoma, who presented with acute renal failure requiring renal replacement therapy and was diagnosed with anti-GBM disease. This case highlights potentially important mechanistic links between lung cancer, immunotherapy and anti-GBM disease development. In line with previous research, there is evidence that breakdown of self-tolerance in response to ICIs may predispose patients to the development of autoimmune disease. In patients on ICIs presenting with acute renal failure, it is important to consider anti-GBM disease as an aetiology alongside more common acute tubulointerstitial nephritis seen in immune-related adverse events of the kidney.