An immunobead assay for antibodies to spermatozoa in serum. Comparison with traditional agglutination and immobilization tests.

Circulating sperm antibodies have been traditionally quantified by measuring sperm agglutination (SAT) and immobilization (SIT) in serum. Recently an indirect immunobead assay (IBA) for detecting these antibodies in serum has been reported. Immunobeads coated with rabbit antibody to one of the three major immunoglobulins (IgG, IgM and IgA) are used. The procedure involves mixing a Hepes washed sample of normal donor sperm with the individual sera followed by centrifugation and incubation with each type of immunobead preparation and observed for evidence of binding. Sera from 40 patients previously tested with SAT and SIT were compared in four groups. There was a good correlation between IgG-IBA and SIT and a poor correlation between IgG-IBA and SAT. The class of immunoglobulin detected most frequently was IgG.