Mesangial deposition of J chain-linked polymeric IgA in IgA nephropathy.
Renal biopsy specimens from 8 patients with IgA nephropathy (Berger's disease) were examined immunocytochemically at the light and electron microscopic levels with peroxidase-labeled antibodies to IgA, IgM, J chain and secretory component. In 2 of the 8 specimens heavy deposits of IgA, but no IgM, were found in the mesangium. After acid-urea treatment of these tissue sections, J chain, a subunit of polymeric immunoglobulins, was identified in a distribution similar to that of IgA. In the remaining 6 specimens, small amounts of IgM in addition to denser deposits of IgA and J chains were found. We conclude that the IgA deposits in at least some patients with Berger's disease consist of IgA polymers linked by J chain.
D000818:Animals; D001485:Basement Membrane / Q000648:ultrastructure; D005921:Glomerulonephritis / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism*; D007144:Immunoglobulin J-Chains / Q000378:metabolism*; D007678:Kidney Glomerulus / Q000648:ultrastructure*; D008854:Microscopy, Electron; D011817:Rabbits
D007070:Immunoglobulin A; D007144:Immunoglobulin J-Chains