title: Demonstration of 11S IgA antibody to spermatozoa in human seminal fluid.
abstract: Spontaneous sperm agglutination was observed in the ejaculate of a 39-year-old male (patient Z). Using an enzyme-linked immunosorbent assay (ELISA) with spermatozoa fixed to wells of a microtitre plate it was determined that IgA was associated with patient Z's spermatozoa but not with a pooled sample of spermatozoa from fertile men Z's seminal fluid agglutinated human spermatozoa (titre 1:16). In contrast, no sperm-agglutinating or immobilizing activity was present in the patient's serum. Agglutination was prevented by preincubation of the seminal fluid with anti-IgA antibody but not with anti-IgA antibody. IgG from Z's seminal fluid readily bound to human spermatozoa, as determined by the ELISA assay. IgA from a pool of seminal fluids from fertile men or from 18 human sera bound to spermatozoa to a much lesser extent. By sucrose-gradient velocity centrifugation it was demonstrated that the anti-sperm IgA in patient Z's seminal fluid was 11S. Finally, antibody to secretory component removed the anti-sperm IgA from Z's seminal fluid. These data provide evidence that secretory IgA with anti-sperm activity is produced in the male genital tract. Furthermore, a new methodology is presented for the determination of antibodies to spermatozoa.
mesh_terms: D000328:Adult; D000918:Antibody Specificity; D001323:Autoantibodies / Q000032:analysis; D002449:Cell Aggregation; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis*; D008297:Male; D012635:Secretory Component; D012661:Semen / Q000276:immunology*; D013094:Spermatozoa / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D007070:Immunoglobulin A; D012635:Secretory Component