ROLE OF SERUM ANTIBODIES TO STREPTOCOCCI IN PATIENTS WITH IGA NEPHROPATHY

Serum antibodies to whole cells of streptococci and serum immune compl exes were investigated in patients with IgA nephropathy accompanied by tonsillitis and in healthy adult controls by enzyme-linked immunosorb ent assay (ELISA). Serum IgA levels to Streptococcus salivarius, S. sa nguis I and S. pneumoniae were higher in patients with IgA nephropathy than in healthy controls. The levels of IgG to S. pyogenes T12, S. go rdonii and S. sauguis II in patients with IgA nephropathy were also hi gher than in healthy controls. Serum immune complexes of IgG and IgA w ere higher in patients with IgA nephropathy than in healthy controls. Serum levels of IgA to some strains of streptococci tended to correlat e with the level of IgA immune complex in both patients and healthy co ntrols. These results suggest that antibodies to strains of streptococ ci play a role in the pathogenesis of IgA nephropathy.