A solid-phase assay for the detection of anti-F(ab′)2 antibodies is described. Wells of microtiter plates are coated with F(ab′)2, dilutions of sera are added, and IgG bound to the solid phase is detected using peroxidase-labeled Protein A. Anti-F(ab′)2 antibodies were found in 61% of sera from patients with rheumatoid arthritis, 77% with subacute bacterial endocarditis, and 34% with systemic lupus erythematosus. Simultaneous analysis of these sera for immune complexes (IC), using modified Clq and monoclonal rheumatoid factor assays, showed that a correlation existed between anti-F(ab′)2 antibodies and the levels of IC. Characterization of anti-F(ab′)2 antibodies by inhibition and absorption experiments and by immunological and physical means indicated that they were similar to serum proteins described in the 1960s and designated pepsin agglutinators.
ASJC Scopus subject areas
- Immunology and Allergy