[3] Apart from breaching of blood-testis barrier, epididymal distension, raised intraluminal pressure, and sperm granuloma formation leading spermatozoal phagocytosis seem to be contributing factors.
[7][8] In both men and women, ASA production are directed against surface antigens on sperm, which can interfere with sperm motility and transport through the female reproductive tract, inhibiting capacitation and acrosome reaction, impaired fertilization, influence on the implantation process, and impaired growth and development of the embryo.
These particles are used either to identify ASA bound to sperm (direct IBT), or ASA present in various biological fluids – seminal plasma, cervical mucus, uterine, oviduct or follicular fluid (indirect IBT); the latter one requires addition of donor ASA-free sperm.
[11] The test is performed 8–12 hours after an unprotected sexual intercourse at the estimated time of ovulation, when the cervical mucus is least viscous and thus most permeable for the sperm.
Generally, the main drawback of all tests used for the diagnosis of ASA is a heterogeneity of data presented in available studies, caused by lack of method standardisation, various semen preparations, and inconsistent cut-off values.
Immunosuppressive therapy comprising corticosteroids or ciclosporin has been proposed by several authors with promising results, nevertheless large randomized controlled trials failed to show a clear benefit.
Owing to sometimes severe adverse effects, many clinicians are reluctant to treat immune infertile patients with above mentioned drugs.
[13] However, this method has not been adopted by clinicians as some concerns exist regarding a possible negative impact of this digestive enzyme on sperm surface receptors involved in fertilization.
[14] In vitro fertilization (IVF) reaches lower pregnancy rates in ASA-positive individuals – basically, the higher ASA titers, the more negative outcome.
If intracytoplasmic sperm injection (ICSI) is added to IVF, similar outcome has been observed in both ASA-positive and ASA-negative couples.
Additionally, some of the sperm surface antigens might be incorporated into the plasma membrane of the embryo resulting in postfertilization negative impact of ASA.
[citation needed] Research has been conducted, but not clinically tested, to use sperm antigens or recombinant ASAs as contraceptive vaccines for humans,[22] as well as captive and wild animals.