Cubilin is a Novel Target Antigen in Anti-Brush Border Antibody Disease

Autoimmune diseases that affect the kidney proximal tubule (PT) cause proteinuria and are implicated in the pathogenesis of kidney failure. Previous evidence demonstrated that circulating anti-brush border antibodies (ABBA) target megalin (LRP2) but whether other components of the PT drive autoimmunity was unknown. Here we investigate a patient with LRP2-negative ABBA disease, and applied immunoprecipitation, mass spectrometry, and confocal imaging to identify cubilin as a novel antigen associated with the autoimmune disorder.