Blog entry by Meguid El Nahas
Another paper, another antigen implicated in the pathogenesis of membranous nephropathy. The last few years saw a plethora of putative antigens from neutral endopeptidase (NEP), to PLA2R1 as well as superoxide dismutase and aldose reductase, all with auto-antibodies and immune deposits in the glomeruli of patients with idiopathic membranous nephropathy (IMN). Now a paper by Debiec and the Ronco team in Paris revisit the old hypothesis that cationic bovine serum albumin can be a causative factor in the pathogenesis of IMN in children. They demonstrate the presence of circulating cationic BSA in some children who have IMN along with anti-BSA antibodies and deposition of cationic BSA in the glomeruli. There evidence suggests that cationic BSA may be pathogenic through binding to anionic GBM and the formation of in situ immune complexes. Clearly, more antigens and antibodies are implicated in a disease that is likely to be initiated by damage to the GBM or podocytes with secondary formation of an array of auto-antibodies. BSA and milk proteeins is another story!