title: Isolation and analysis of immune complexes from sera of patients with polymyalgia rheumatica and giant cell arteritis.
abstract: Serum samples were obtained from patients with polymyalgia rheumatica (PMR: n = 10) or giant cell arteritis (GCA; n = 7), or both. Samples were taken either before treatment or within one week of starting prednisolone. Immune complexes (IC) were concentrated by polyethylene glycol (PEG) precipitation then purified with either IgG anti-C1q-Sepharose or IgG anti-C3c-Sepharose. Complex components were separated by sodium dodecyl sulphate (SDS) gradient polyacrylamide gel electrophoresis then transferred to nitrocellulose by Western blotting. Identification of proteins was carried out using specific antisera. All the IC contained IgM (mu chain), some contained IgA (alpha chain), and IgG (gamma chain). C1r, C1s, C1q, C3, C4, and C reactive protein (CRP), where tested, were found in most but not all IC. The occurrence of properdin, factor B, alpha 2 macroglobulin (alpha 2M), factor H (beta 1H), C1 esterase inhibitor, and C4 binding protein was also investigated. Immune complexes in PMR and GCA differed from those previously characterized in rheumatoid arthritis (RA)1 purified by anti-C1q-Sepharose which contained immunoglobulins and C1q only. No properdin or factor B were detected in RA IC purified with either anti-C1q-Sepharose or anti-C3c-Sepharose.
authors.forename: A J
authors.initials: AJ
authors.lastname: Smith
authors.forename: V
authors.initials: V
authors.lastname: Kyle
authors.forename: T E
authors.initials: TE
authors.lastname: Cawston
authors.forename: B L
authors.initials: BL
authors.lastname: Hazleman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000936:Antigen-Antibody Complex / Q000032:analysis*; D001345:Autoradiography; D003166:Complement Activating Enzymes / Q000276:immunology; D003172:Complement C1 / Q000276:immunology; D015922:Complement C1q; D015923:Complement C1r; D003173:Complement C1s; D003176:Complement C3 / Q000276:immunology; D003181:Complement C4 / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D013700:Giant Cell Arteritis / Q000276:immunology*; D006801:Humans; D007106:Immune Sera; D008875:Middle Aged; D011111:Polymyalgia Rheumatica / Q000276:immunology*
chemical_list: D000936:Antigen-Antibody Complex; D003172:Complement C1; D003176:Complement C3; D003181:Complement C4; D007106:Immune Sera; D015922:Complement C1q; D003166:Complement Activating Enzymes; D015923:Complement C1r; D003173:Complement C1s