[Immunoelectron microscopic studies of IgA nephropathy in children]

The distribution of IgA, IgG, IgM and C3 in kidney biopsy specimens from 28 children with IgA nephropathy were examined by immunoelectron microscopy. In all 28 patients IgA reaction products (RP) were observed within the mesangial matrix, corresponding to electron-dense deposits identified by conventional electron microscopy. Occasionally IgA-RP were noted along the peripheral glomerular capillary loops: subendothelial 26/28 (93%), intramembranous 15/28 (54%) and subepithelial 8/28(29%). The pattern of IgG, IgM, and C3-RP observed in glomeruli was similar to that of IgA, but the incidence and intensity of these proteins in glomeruli were less than those of IgA. These results suggest that IgA and other immunoglobulins were deposited as immune-complex in glomeruli.