Measurement of complement activation products in patients with chronic rheumatic diseases.
Measurement of the complement activation products C1s:C1-inh, C3bP and C5b-9 by ELISA in plasma samples from normals, rheumatoid arthritis (RA) and systemic lupus erythematosis (SLE) patients showed significantly elevated levels in the two patient groups (P less than 0.0001 for C1s:C1-inh, C3bP and C5b-9) compared to normals. In seropositive RA patients there were significant correlations between the levels of the three complement activation complexes and IgM-RF, IgG-RF and IgA-RF. However, IgM-RF did not interfere with any of the ELISA systems. Mean levels of C1s:C1-inh, C3bP and C5b-9 were the same in paired plasma and synovial fluids; however, C3bP levels in the paired samples did not correlate with one another by rank. Our conclusions are that: (a) elevated plasma levels of these complement activation products are detectable in rheumatic diseases; (b) plasma levels of these complement activation products are related to Rheumatoid factor (RF) levels in seropositive RA patients; and (c) IgM-RF does not influence these solid-phase ELISA procedures.
Auda
G
G
University Department of Pathology, Western Infirmary, Glasgow, UK.
Holme
E R
ER
Davidson
J E
JE
Zoma
A
A
Veitch
J
J
Whaley
K
K
D000906:Antibodies / Q000276:immunology; D002908:Chronic Disease; D003167:Complement Activation / Q000187:drug effects / Q000276:immunology*; D003174:Complement C1 Inactivator Proteins / Q000032:analysis*; D003173:Complement C1s / Q000032:analysis / Q000276:immunology; D003179:Complement C3b / Q000032:analysis; D003182:Complement C5 / Q000032:analysis; D050776:Complement C5b; D003186:Complement C9 / Q000032:analysis / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology; D012216:Rheumatic Diseases / Q000097:blood* / Q000276:immunology; D012217:Rheumatoid Factor / Q000494:pharmacology; D013582:Synovial Fluid / Q000737:chemistry
D000906:Antibodies; D003174:Complement C1 Inactivator Proteins; D003182:Complement C5; D003186:Complement C9; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D003179:Complement C3b; D050776:Complement C5b; D012217:Rheumatoid Factor; D003173:Complement C1s