Abstract
Advances in monoclonal antibody technology have enabled the application of engineered antibodies to interfere with specific immune pathways. Checkpoint inhibitors have shown promising results in treating certain cancers by employing patients' own immune systems to attack cancer cells. Checkpoint inhibitors release the brake on the immune system and can cause immune-related diseases. Theoretically this could be disadvantageous in patients with autoimmune diseases. Here I describe a case of nephrotic syndrome relapse in a patient with a history of membranous nephropathy during programmed death-ligand 1 inhibitor therapy for lung cancer. It is postulated that enhancement of the immune system triggered the relapse of nephrotic syndrome by leading to an escape of immune tolerance and increased susceptibility.