title: C3 activation products, C3 containing immune complexes, the terminal complement complex and native C9 in patients with rheumatoid arthritis.
abstract: Complement activation products, C9 and C3-containing circulating immune complexes (CIC), were evaluated in plasma and synovial fluid (SF) from patients with rheumatoid arthritis (RA) and osteoarthritis. C3 activation products and the fluid phase terminal complement complex were considerably elevated in SF from RA patients reaching levels five- to eighttimes that in plasma, consistant with a local activation of the whole cascade in the joints. The results emphazise the importance of detecting C3 activation by neoepitope expression instead of single fragment determinations. The concentration of native C9 was lower in synovial fluid compared with plasma, consistant with the excessive local complement activation. Increased CIC levels which correlated with the degree of complement activation were also found in the SF from the RA patients.
authors.affiliation: Institute of Immunology and Rheumatology, National Hospital, Oslo, Norway.
authors.forename: U
authors.initials: U
authors.lastname: Olmez
authors.forename: P
authors.initials: P
authors.lastname: Garred
authors.forename: T E
authors.initials: TE
authors.lastname: Mollnes
authors.forename: M
authors.initials: M
authors.lastname: Harboe
authors.forename: H B
authors.initials: HB
authors.lastname: Berntzen
authors.forename: E
authors.initials: E
authors.lastname: Munthe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000936:Antigen-Antibody Complex / Q000032:analysis*; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D003167:Complement Activation; D003176:Complement C3 / Q000502:physiology*; D015933:Complement C3d / Q000032:analysis; D003186:Complement C9 / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012217:Rheumatoid Factor / Q000032:analysis
chemical_list: D000936:Antigen-Antibody Complex; D003176:Complement C3; D003186:Complement C9; D015933:Complement C3d; D012217:Rheumatoid Factor