A method to differentiate between anti-C1q antibodies and C1q-binding immune complexes using collagenase-digested solid phase C1q.
A method for the detection of circulating immune complexes in the presence of autoantibodies to C1q is described. Solid phase C1q-digestion with bacterial collagenase results in the elimination of the collagen-like region of C1q. Binding of model immune complexes to this modified solid phase C1q is practically unaltered, while reactivity of anti-C1q antibodies is abolished by this procedure. In conjunction with an ELISA using the collagen-like region of C1q as antigen this modified C1q solid phase assay may be used to determine immune complexes and anti-C1q antibodies in the sera of patients with autoimmune rheumatic diseases.
Menzel
J E
JE
Institute of Immunology, Vienna, Austria.
Scherak
O
O
Kolarz
G
G
Gamerith
F
F
Youngchaiyud
U
U
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology*; D015922:Complement C1q / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D016130:Immunophenotyping / Q000379:methods; D003012:Microbial Collagenase / Q000276:immunology*; D012216:Rheumatic Diseases / Q000276:immunology
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D001323:Autoantibodies; D015922:Complement C1q; D003012:Microbial Collagenase