• antisperm antibodies;
  • male infertility;
  • spermatozoa;
  • sperm penetration assay;
  • zona pellucida

PROBLEM: This study was performed to evaluate the occurrence as well as the level of the interference of sperm-associated antibodies on fertilization process.

METHOD: Motile sperm suspensions from 28 infertile patients with high degree of autoimmunization against the sperm head were tested with the zona pellucida (ZP) binding test and with the sperm penetration assay (SPA) enhanced with TEST-yolk buffer. Both tests were also performed using donor sperm exposed and non-exposed to the patients' circulating sperm antibodies.

RESULTS: A low ZP-binding was exhibited by sperm from 50% of patients with normal semen profile. All normozoospermic patients with low ZP-binding showed circulating sperm-antibodies with inhibitory effect on ZP-binding, while no patient with normal ZP-binding showed circulating sperm-antibodies with inhibitory effect. No normozoospermic patient exhibited a negative SPA result, and only in 16% of cases the penetration index was slightly less than 2 (the lowest value exhibited by fertile controls). Circulating antisperm-antibodies did not significantly affect the hamster egg penetration.

CONCLUSION: Even in the presence of high degree of autoimmunization against the sperm-head, sperm fusion with oolemma is not impaired after sperm preincubation with TEST-yolk buffer, while an impairment of the ZP-binding is demonstrable in half cases, when non-immunologic factors are excluded. A substantial role in this interference is likely exerted by IgG antibodies transuded from the blood into the genital tract.