Terminal complement complexes and C1/C1 inhibitor complexes in rheumatoid arthritis and other arthritic conditions.
Terminal complement complex (TCC) and C1r-C1s-C1 inhibitor complex (C1/C1 INH) concentrations were measured in plasma and synovial fluid from patients with arthritis and related to other measures of disease activity. Both TCC and C1/C1 INH concentrations were significantly increased in patients with rheumatoid arthritis (RA) compared with patients with osteoarthritis (plasma and synovial fluid, P less than 0.05) and normal subjects (plasma only, P less than 0.001). In the patients with RA, there was no correlation between plasma or synovial fluid TCC concentrations and IgM rheumatoid factor, immune complex or C1/C1 INH levels. However, in 10 patients with seronegative RA, C1/C1 INH and immune complex levels correlated significantly in synovial fluid (r = 0.69, P less than 0.05) although not in plasma (r = 0.52). Plasma and synovial fluid TCC and C1/C1 INH concentrations did not differ in rheumatoid patients with severe compared with mild joint disease (categorized by the Ritchie score). These results confirm a role for complement activation in RA but suggest that several mechanisms are involved in its pathogenesis.
Oleesky
D A
DA
Department of Medical Biochemistry, University Hospital of Wales, Heath Park, Cardiff.
Daniels
R H
RH
Williams
B D
BD
Amos
N
N
Morgan
B P
BP
D000328:Adult; D000368:Aged; D000936:Antigen-Antibody Complex / Q000276:immunology*; D001168:Arthritis / Q000276:immunology*; D015535:Arthritis, Psoriatic / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000276:immunology; D003167:Complement Activation / Q000502:physiology; D003172:Complement C1 / Q000276:immunology; D003174:Complement C1 Inactivator Proteins / Q000032:analysis*; D003182:Complement C5 / Q000276:immunology; D003183:Complement C6 / Q000276:immunology; D003184:Complement C7 / Q000276:immunology; D003185:Complement C8 / Q000276:immunology; D003186:Complement C9 / Q000276:immunology; D003165:Complement System Proteins / Q000032:analysis / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000276:immunology; D012217:Rheumatoid Factor / Q000032:analysis; D013582:Synovial Fluid / Q000737:chemistry
D000936:Antigen-Antibody Complex; D003172:Complement C1; D003174:Complement C1 Inactivator Proteins; D003182:Complement C5; D003183:Complement C6; D003184:Complement C7; D003185:Complement C8; D003186:Complement C9; D007075:Immunoglobulin M; D003165:Complement System Proteins; D012217:Rheumatoid Factor