Characterization of complement-fixing activity and cross-idiotypes of rheumatoid factors in idiopathic mixed cryoglobulinemia.
The complement-fixing activity, specificity for IgG, and cross-idiotypes of rheumatoid factors (RF) isolated from the mixed cryoglobulins of nine patients with idiopathic mixed cryoglobulinemia were determined. All were IgM kappa and fixed complement. The RF complement-fixing activity did not correlate with hypocomplementemia or disease manifestations. The majority of RF belonged to the same cross-idiotype group. The RF from two of three patients with predominantly neurologic manifestations did not have any of the known cross-idiotypes and reacted better with rabbit IgG than with human IgG. The patients with neurologic manifestations also differed in that their serum complement was normal.
D000328:Adult; D000368:Aged; D003167:Complement Activation; D003165:Complement System Proteins / Q000032:analysis; D003449:Cryoglobulinemia / Q000276:immunology*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007130:Immunoglobulin Idiotypes / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis*; D007145:Immunoglobulin kappa-Chains / Q000032:analysis; D008875:Middle Aged; D010265:Paraproteinemias / Q000276:immunology*; D012217:Rheumatoid Factor / Q000276:immunology*
D007074:Immunoglobulin G; D007130:Immunoglobulin Idiotypes; D007075:Immunoglobulin M; D007145:Immunoglobulin kappa-Chains; D003165:Complement System Proteins; D012217:Rheumatoid Factor