ANTISPERM ANTIBODIES IN INFERTILE WOMEN - SUBCLASS DISTRIBUTION OF IMMUNOGLOBULIN (IG)-A ANTIBODIES AND REMOVAL OF IGA SPERM-BOUND ANTIBODIES WITH A SPECIFIC IGA1 PROTEASE

Objective: To determine the immunoglobulin (Ig) A subclass distributio n of antibodies in the serum and cervical mucus (CM) of infertile wome n and to evaluate the effect of an IgA1 protease on the removal of spe rm-bound antibodies. Methods: Twenty infertile women with antisperm an tibodies in serum (n = 10) or in CM (n = 10) were recruited for this s tudy. Monoclonal antibodies to human IgA1 and IgA2 were conjugated to immunobeads and the IgA subclass distribution of antisperm antibodies was determined for positive serum and CM samples. The effect of an IgA 1 protease (isolated from Neisseria meningitidis strain HF13) on sperm -bound antibodies was evaluated by immunobead binding. Results: In ser um, IgA1 subclass antisperm antibodies predominated (89%) when compare d to IgA2 (11%). In CM IgA1 accounted for 62% and IgA2 accounted for 3 8% of the total IgA antisperm antibodies. Enzyme treatment was able to reduce dramatically the amount of serum IgA antibodies bound to sperm from 88% to 10%. Similarly, a significant reduction in CM antisperm a ntibodies was observed after enzymatic treatment with no loss in sperm motility. Conclusion: Cervical mucus antisperm antibodies have a high er proportion of IgA2 subclass suggesting a local production of IgA. S pecific IgA1 protease treatment is capable of reducing the amount of i mmunobead-detectable IgA on sperm. Hamster sperm penetration assays ar e ongoing to determine if this treatment might improve sperm penetrati on rates with antibody positive sperm.