B-cell alloantigen associated with chronic mesangiocapillary glomerulonephritis.

Thirteen patients with chronic mesangiocapillary glomerulonephritis (M.C.G.) defined by light and immunofluorescent microscopy were examined for possible B-lymphocyte alloantigen associations by means of antisera from multiparous mothers of M.C.G. probands. Three such sera reacted with M.C.G.-patient B-cells. One of these sera (M.C.G.3) was highly discriminative for a B-cell antigen present in 77% of M.C.G. patients and only 17% of normal individuals tested. The risk of developing M.C.G. was estimated to be 16-6 times greater in the presence of the M.C.G.3 antigen than in its absence. This is the first demonstration of an association between a specific B-lymphocyte determinant and immune-mediated glomerulonephritis.