IgM nephropathy: timely response to a call for action

Immunoglobulin M (IgM) is the largest antibody molecule and is deposited in the glomeruli in a wide variety of both primary and secondary glomerulopathies. The data on its pathogenic role are conflicting till date. A recent study provides evidence for the involvement of natural antibody IgM in fixing and activating complement and causing glomerular injury, proteinuria, and glomerulosclerosis in an animal model. This finding is important in understanding the pathogenesis of the related disorder of IgM nephropathy.