What to do if the blocking antibody of pregnant women is negative

Pregnant women themselves need to take prenatal check-ups seriously. Moreover, once the blocking antibody is found to be negative during the prenatal check-up, there will often be various uncomfortable symptoms. And when pregnant women are tested to have negative blocking antibodies, they are also very worried. And there are even concerns that it may harm the fetus. What treatment is needed for a pregnant woman who is found to have negative blocking antibodies?

In the serum of normal pregnant women, there is a specific IgG antibody against spouse lymphocytes, which can inhibit lymphocyte response (MLR), block the cytotoxic effect of maternal lymphocytes on cultured trophoblasts, prevent helper T cells from recognizing inhibitors of fetal antigens, and prevent the mother's immune system from attacking the embryo. It blocks the production of macrophage migration inhibitory factor (MIF) by lymphocytes stimulated by alloantigens, so it is called blocking antibody.

The main types of blocking antibodies discovered so far are as follows:

1. Anti-warm B cell antibodies: Anti-HLA-D/DR antibodies on the surface of fetal B lymphocytes;

2. Anti-cold B cell antibodies: non-HLA cold B antibodies;

3. Anti-specific antibodies: Genetic antibodies against HLA-D/DR receptors on the surface of maternal helper T cells;

4. Anti-TLX antibody: It is an antibody against common antigens of villi and lymphocytes, which can block mixed lymphocyte reaction;

5. Anti-Fc receptor antibodies: non-cellular blocking antibodies that block Fc receptors on B lymphocytes;

6. Anti-paternal complement-dependent antibodies (APCA).

Causes

In a normal pregnancy, the HLA antigens of the couple are incompatible. The paternal HLA antigens carried by the embryo (on the surface of trophoblast cells) can stimulate the maternal immune system and produce blocking antibodies (APLA), that is, specific IgG antibodies (APLA) against the spouse's lymphocytes, which can inhibit mixed lymphocyte reactions and bind to the HLA antigens on the surface of trophoblast cells, covering the HLA antigens from the father, thereby blocking the cytotoxic effect of maternal lymphocytes on trophoblast cells and protecting the embryo or fetus from rejection.

Couples with recurrent spontaneous abortions have a higher frequency of containing the same HLA antigens than normal couples. Too many shared antigens prevent the mother from recognizing the pregnant embryo as a foreign antigen and cannot stimulate the mother to produce enough APLA to maintain pregnancy, resulting in a negative blocking antibody test.

Wait until the antibody test is positive before getting pregnant to ensure a successful pregnancy. During the treatment, medical staff drew a certain amount of peripheral blood from the husband for centrifugal sedimentation to separate and culture lymphocytes, and then infused them back into the skin of his wife's forearm. After pregnancy, another course of consolidation treatment should be carried out to ensure stability during the pregnancy. Generally, one course of treatment consists of 4 treatments, with a 2-week interval between each treatment.

Pregnant women who are tested positive for blocking antibodies need to receive active treatment. Moreover, for some more serious patients with negative blocking antibodies, it is often beneficial if the patient's spouse is recommended to undergo white blood cell immunotherapy. In this case, the levels of blocking antibodies in some patients with recurrent spontaneous abortion will often increase.