Anti-sperm antibodies

Antisperm antibodies are antibodies that are produced directly to antigens contained in the sperm membrane.

In other words, when a woman's or man's immune system malfunctions, the body begins to attack the sperm, causing infertility in both sexes.

Antisperm antibodies in women The reasons for the formation of antisperm antibodies in the body of women are not yet sufficiently studied, but there are several theories that can explain this pathology: In the normal course of ovulation, cellular mechanisms that block the activity of immune cells trigger, i.e., there is a decrease in the general and local mechanisms of immune response, which protects sperm from recognizing them as antigens immunocompetent cells of the mother.

But in some pathological conditions, associated, for example, with infectious processes of the female genital system (chlamydia, trichomoniasis, etc.), there is an excessive activation of the general and local mechanisms of immunity, which may cause the recognition of spermatozoa as antigenic structures and the production of appropriate antibodies to them.

Taking immunostimulatory drugs which causes in some cases hyperactivity of immune cells. In this case, immunocompetent cells begin to perceive spermatozoa as foreign cells that were not previously recognized as antigenic structures.

Antisperm antibodies in men The genetic structure of spermatozoa differs by 50% from the structure of other male cells. Consequently, if the male immune system "meets" spermatozoa, it begins to attack them.

Fortunately, under physiological conditions, there are a number of mechanisms that protect male germ cells from autoaggression, but when certain pathological processes develop, the defense mechanisms collapse and spermatozoa are subjected to recognition by the male body's own immune cells as antigenic structures: Normally, spermatozoa develop due to the functioning of Sertoli cells in the testicles, which on the one hand produce a number of enzymes that ensure the growth and development of sperm, and on the other hand, form a blood-testis barrier (a barrier between the bloodstream and the testicle), preventing the penetration of immune cells from the blood into the testicle of a man.

When this barrier is broken due to an inflammatory reaction or mechanical damage, immune cells easily penetrate the blood-testis barrier and begin to perceive spermatozoa as antigenic structures. It is important to note that antibodies are not produced to the spermatozoon, but to its individual parts; antibody production occurs to certain protein units that are part of the whole cell.

When immune cells encounter an adult sperm cell under normal conditions, immune reactions will never develop because some of the protein molecules to which autoimmune reactions could develop are covered by other protein structures with which the immune cells are familiar and therefore will not be aggressive toward them.

Another case is when the barrier is damaged and immune cells encounter protein molecules with which they were not previously familiar, and those, in turn, have not yet had time to acquire the ability of invisibility. In the process of sperm development there is insufficient production of substances and enzymes for its normal functioning, which may be associated with general inanition of the body due to acute and chronic diseases or prolonged starvation.

In this regard, the adult spermatozoon may not receive in its arsenal a certain part of the mechanisms that prevent it from being recognized as an antigen by the cellular structures of the female body, such as the immunosuppressive factor of sperm plasma.

All the above-mentioned processes in one way or another, eventually lead to the production of antisperm antibodies and their constant circulation in the bloodstream of both male and female organism, which makes the process of fertilization under physiological conditions near-impossible.