Antisperm antibodies

Antisperm antibodies, abbreviated as ASAT, are specific proteins of the human immune system, which can appear in both men and women for various reasons. In the first case it is an autoimmune process, in the second case it is an immunological incompatibility between the spouses.

Such disorders contribute to a decrease in sperm motility, worsen the process of fertilisation of the egg cell, have a negative impact on the growth and development of the embryo. If a couple is to undergo IVF treatment, an ASAT test is a prerequisite.

Human reproductive function also depends on the state of the immune system. Neither ovulation, nor the process of preparing the endometrium for implantation of an egg cell fertilised by a spermatozoon, nor the interaction between gametes, nor the subsequent development of pregnancy can do without the participation of immune cells. If immune haemostasis is altered, it can lead to reproductive process failures: the probability of normal conception decreases, the risk of pregnancy failure increases and infertility develops. It has been reported that in 20% of cases of unexplained infertility, an immune factor is present.

One of the main immune factors that cause infertility, experts call the presence of anti-sperm antibodies. They are detected both in infertile couples and spouses who already have children. Only in the latter case this indicator is only 0.9-4%, while in the former case it is 9-36%! ASAT are immunoglobulins of IgA and/or IgM, IgG isotypes whose action is directed towards sperm membrane antigens.

Antisperm antibodies of various types are found, most often the causes of infertility are due to exposure to more than one type of antisperm antibody. Their formation occurs in men in the ejaculatory ducts, testicular appendages or in the testicles themselves, in women - also in various organs of the reproductive system.

If antisperm antibodies are present in the uterine cervix, it means that they are also present in the lumen of the fallopian tube and the uterine cavity itself. The presence of antisperm antibodies in a woman has a negative effect on spermatozoa motility, greatly reducing the quality of fertilisation of the egg cell.

 Formation of anti-sperm antibodies in males

Before the onset of puberty, the male does not have sperm. For this reason, the immune system perceives the specific antigens inherent in sperm as "foreign". However, it does not attack them, because spermatozoa do not come into contact with immune cells. They are protected by certain physiological mechanisms.

The haematotesticular barrier, which exists between the blood vessels and the spermatic cord, is the first mechanism. This type of barrier is created by the tight junctions between the basal membrane of the Sertoli cells. This barrier prevents immune cells from entering the seminal tubules, thus protecting the testicular cells. Typically, some spermatozoa do enter the bloodstream, triggering an immune response against them.

If the haematotesticular barrier is breached due to infection, trauma or surgery, immune cells can enter the male genital tract, making sperm available to the immune system.

There are several factors that contribute to antisperm antibodies in men:

- infections;

- trauma;

- cancer;

- varicocele;

- cryptorchidism;

- blockage of the ejaculatory tract;

- surgical intervention on the genitals.

Women do not normally form ASATs, even though "foreign" sperm cells enter her body during sexual intercourse. The cells that cover the vaginal mucosa provide a good physiological barrier that prevents sperm cells from penetrating the immune system.

In addition, seminal fluid contains high amounts of prostaglandin E2, which is a potential immune suppressor, and IBF, immunoglobulin binding factor, which ensures that anti-sperm antibodies are not formed in the reproductive tract. But if a woman has an inflammatory process or various infections, immune recognition of sperm can develop.

 Mechanisms contributing to the formation of antisperm antibodies in women

- ingestion of "old" and abnormal spermatozoa into the vagina (if a man has an irregular sex life);

- increased content of leucocytes, including lymphocytes, in the ejaculate;

- ingestion of sperm into the gastrointestinal tract during oral and anal sex;

- chemical contraceptive methods that can compromise the integrity of mucous membranes;

- ingestion of a large number of spermatozoa into the abdominal cavity, which may be caused by the structure of the genital tract, irregularities in the implementation of intrauterine insemination methods;

- ingestion of spermatozoa associated with antisperm antibodies in the vagina;

- coagulation of a previous cervical erosion;

- previous IVF attempts, which may have caused a hormonal "blow" to the hypothalamic-pituitary-ovarian axis, or trauma during egg cell retrieval.

 How anti-sperm antibodies affect reproductive function

- sperm motility is reduced and sperm activity is impaired.  By fixing on the membrane of spermatozoa in its various parts, ASATs inhibit the movement of spermatozoa, and not only when moving in the male reproductive tract, but also in women. Antisperm antibodies often contribute to the immobilisation and agglutination ("sticking") of spermatozoa. The higher the amount of antisperm antibodies, the lower the spermatozoa motility. Sperm activity is also affected by the place of fixation, the most unfavourable being the spermatozoa head;

- preventing spermatozoa from entering the cervical mucus.

- negative effect on the implantation of the fertilised egg cell (blastocyst);

- inhibition of embryo growth and development.

Detection of anti-sperm antibodies

If a couple is considered infertile, an ASAT test should be mandatory at the time of examination. This is the WHO recommendation. Female infertility and fertility problems can sometimes also be associated with their presence.

Various techniques are used to determine the presence of antisperm antibodies in the body. The indirect enzyme-linked immunosorbent assay technology can be used to detect the presence of ASAT in serum.

Antisperm antibody testing for both men and women can be performed in any treatment room of the OLYMP branches of laboratories.