IgA nephropathy and aberrant glycosylation of tonsillar, serum and glomerular IgA1.

Human IgA1, which is the predominant subtype deposited in the glomeruli in IgA nephropathy (IgAN), has a unique mucin-like structure in its hinge region. Several studies suggested that the IgA1 molecules in IgAN patients had an aberrant structure of O-glycans. The paper summarizes the analyses of O-glycan structure in the IgA1 molecules taken from tonsils, sera and glomeruli of patients with IgAN. Hypoglycosylation, especially hypogalactosylation of O-glycans has been observed not only in serum and glomerular IgA1 but also in tonsillar IgA1.