title: Hypocomplementemia in rheumatoid arthritis.
mesh_terms: D000328:Adult; D000368:Aged; D000936:Antigen-Antibody Complex / Q000032:analysis; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000276:immunology*; D001424:Bacterial Infections / Q000209:etiology; D003168:Complement Fixation Tests; D003165:Complement System Proteins / Q000032:analysis*; D005260:Female; D006801:Humans; D005779:Immunodiffusion; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007153:Immunologic Deficiency Syndromes / Q000150:complications*; D008297:Male; D008875:Middle Aged; D011233:Precipitin Tests; D012217:Rheumatoid Factor / Q000032:analysis; D014461:Ultracentrifugation
chemical_list: D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D003165:Complement System Proteins; D012217:Rheumatoid Factor