Infertility antibody test, do you understand this knowledge?

If female friends have infertility, it is necessary to go to the hospital for antibody testing. Because there are many factors that lead to infertility, there are more than one antibody test item. The most common test items are the following:

1. Anti-sperm antibodies

Sperm, as a unique antigen, causes autologous or allogeneic immune response after contact with the body's immune system, producing anti-sperm antibodies. Sperm antigens are usually called hidden antigens. Under normal circumstances, in addition to the blood-testicular barrier that prevents sperm antigens from contacting the body's immune system, the immunosuppressive factors in the seminal plasma also play a certain reproductive protection role. However, when prostatitis, seminal vesiculitis, vas deferens, or testicular infection by mumps virus, trauma, or chemical poisoning occurs, the integrity of the blood-testicular barrier can be destroyed, and when the immunosuppressive effect in the seminal plasma is reduced, sperm or its soluble antigens escape and flow into the blood circulation, causing the body to produce autoantibodies (an·tisperiumantibody, AsAb), resulting in male infertility. The female reproductive tract has an enzyme system that can degrade incoming sperm antigens so that they cannot reach the immune system. Defects in this enzyme system or reduced immunosuppressive effects in seminal plasma, or vaginitis, pelvic inflammatory disease, or sexual intercourse during menstruation caused by microbial infection, can cause sperm to enter the bloodstream through the damaged mucous membrane of the female reproductive tract, keeping sperm antigens intact and stimulating the production of the same anti-sperm antibodies or cross-antibodies, thereby interfering with the normal movement of sperm and causing fertility problems. Approximately 10% to 30% of unexplained female infertility may be due to AsAb.

2. Anti-endometrial antibodies

The endometrium is the place where the embryo implants and grows and develops, and it is also the necessary pathway for sperm to ascend. Under normal circumstances, the endometrium that is shed periodically by women of childbearing age flows out of the body with menstrual blood and generally does not induce an autoimmune response in the body. However, under pathological conditions, such as endometriosis, vaginal manipulation during menstruation, or sexual intercourse during menstruation, the menstrual blood can flow backwards, causing endometriosis to grow and stimulating the surrounding tissues to produce an inflammatory response. Through the phagocytosis of macrophages and absorption by the peritoneum, the body is sensitized and induces systemic and local immune responses, producing anti-endometrial antibodies (EmAb), leading to infertility, stillbirth, or miscarriage. Anti-endometrial antibodies can also be seen in other gynecological diseases, such as pelvic inflammatory disease. In addition, the production of anti-endometrial antibodies may also be related to the body's immune system disorders. In patients with unexplained infertility, the detection rate of anti-endometrial antibodies is as high as 73.9%.

3. Anti-ovarian antibodies

Ovarian tissue or cells, as a special antigen, stimulate the body to produce anti-ovarian antibodies (antiovarianantibody, AoAb). Studies have reported that patients with premature ovarian failure have positive anti-ovarian antibodies, patients with certain polyglandular autoimmune diseases may have elevated levels of anti-ovarian antibodies, and some patients with unexplained infertility may also have elevated specific or nonspecific autoantibodies.

4. Anti-cardiolipin antibodies

Anticardiolipin antibody (AcAb) is an autoantibody, a heterologous antibody against negatively charged phospholipids. It belongs to the same category of antiphospholipid antibodies as lupus anticoagulant (LA). It is closely related to adverse pregnancy outcomes such as recurrent miscarriage, stillbirth, and neurological diseases such as systemic lupus erythematosus, neurosyphilis, multiple sclerosis, and Guillain-Barré syndrome. Antiphospholipid antibodies can bind negatively to the surface of platelets and endothelial cells containing phospholipids in the circulation, and play an important role in the mechanism of thrombosis. Antiphospholipid antibodies can be seen in autoimmune diseases, certain infectious diseases, drug effects or diseases of unknown causes. If the patient's antiphospholipid antibodies are positive, the incidence of habitual abortion is extremely high, and repeated abortions, stillbirths, placental infarction and reduced perinatal fetal survival rates may occur. Because antiphospholipid antibodies are not the only antibodies associated with miscarriage, other antibodies should be tested simultaneously. The target antigen of anti-cardiolipin antibodies is the negatively charged cardiolipin on the membranes of vascular endothelial cells and platelets.