In these years, closed antibody is a popular term, in the clinic often encounter patients with closed antibody test sheets to consult, most patients think that the test sheet negative is normal, positive is abnormal, they closed antibody negative need to be treated, many patients are expressed puzzled. Closed antibodies are a class of antibodies produced by human leukocyte antigens stimulating the maternal immune system. Studies have concluded that antibodies in the blood of pregnant women can perform the following roles: 1. and allogeneic antigens without rejection of the fetus; 2. antibodies act directly on immunocompetent cells; 3. bind directly to the antigens of target cells, thereby reducing their sensitivity to the immune response involving the recipient cells. The occurrence of recurrent spontaneous abortions is associated with a maternal deficiency of closed antibodies, and the greater the number of miscarriages, the greater the likelihood of a deficiency of closed antibodies in the patient. Therefore, the lack of production of closed antibodies leads to a strong rejection of the fetus by the mother, which can occur in early pregnancy, and in late pregnancy, which can lead to hypertensive disorders of pregnancy, intrauterine growth restriction, or even intrauterine death. Therefore, it is necessary to test patients with recurrent spontaneous miscarriages for closed antibodies. So what is it about closed antibody testing that is so highly sought after by doctors and patients? Let’s learn more about it. 1. What is a closed antibody? The embryo is a combination of the father’s sperm and the mother’s egg, and carries the genetic material of both the mother and father, half from the mother and the other half from the father, so the embryo is a foreign “little thing” to the mother’s uterus, and the mother’s immune system will automatically “attack” the embryo to cause spontaneous abortion. The mother’s immune system will automatically “attack” the embryo causing a spontaneous abortion. If this were true, most embryos would miscarry and not be able to sustain the pregnancy, but we know that this is not the case, so why is this? It turns out that this is all due to “closed antibodies”. “Containment antibodies are antibodies that protect the embryo in the mother’s body and play an important role in the process of embryo implantation, and are considered essential to maintain the pregnancy. In terms of the medical immune mechanism, the antibody binds to the mother’s cytotoxic lymphocytes, blocking their cytotoxic effect and preventing the killing of the fetus; on the other hand, it binds to the antigen on the embryo, blocking the direct immune recognition of the mother and child. Once the “closed antibody” is lacking, the mother’s immune system is prone to immune attack on the embryo, eventually leading to failure of embryo implantation or spontaneous abortion. Therefore, unlike most antibody test results, a negative antibody test means an abnormality. 2. What kind of patients need to be tested for closed antibody? Many doctors prescribe antibody tests as soon as they see a patient, and some patients do not even have a history of pregnancy and miscarriage or IVF treatment, which is completely unnecessary. Although closed antibody has an important role in embryo implantation, not every patient needs to have a closed antibody test. Generally, we recommend considering a closed antibody test only for patients who have had repeated failed IVF or recurrent miscarriages. Every patient is different and if your doctor does not prescribe a closed antibody test, there is no need to be overly nervous or compare yourself to other patients. There is a real trend in China to correct this. 3.How do I treat a negative closed antibody? Since there is a lack of closed antibody, we need to stimulate the mother’s body to produce this protective antibody, and this treatment process is clinically called “husband lymphocyte immunotherapy”. The name sounds very grand, but the actual treatment process is not mysterious. Simply put, the father’s blood is extracted from the lymphocytes, processed and then injected into the mother’s body to produce closed antibodies through repeated stimulation. The general treatment plan is once every 2 to 4 weeks, 4 times as a course of treatment, after completing the treatment review, which means that a course of treatment will take at least 2 to 4 months. Patients who need treatment are advised to prepare in advance for a positive re-test before embryo transfer. It should be noted that since the treatment requires the father’s blood, if the father suffers from diseases that can be transmitted through blood such as hepatitis and syphilis, he is not suitable to provide blood for the mother, in which case the father’s siblings can be asked to act as blood donors for the treatment. 4.Do I need to do closed antibody treatment for repeated failures of IVF? In the process of assisted reproduction, some patients may have multiple unsuccessful embryo transfers, causing great problems to both patients and doctors. This is medically referred to as recurrent implantation failure, which generally means that more than 3 embryo transfers or a cumulative total of more than 4 quality embryos have failed to conceive. There are many reasons for recurrent implantation failure, mainly related to embryonic and maternal factors. Embryonic factors include chromosomal number or structural abnormalities, genetic abnormalities and embryonic developmental potential, which are important factors affecting embryo quality and transfer success. Maternal factors include endometrial factors, endocrine factors, coagulation abnormalities, and immune factors, among which immune factors refer to abnormal maternal immune function, such as abnormally elevated natural killer cell activity, or lack of closed antibodies. It can be seen that there are many reasons for repeated implantation failure, and closed antibody deficiency is only one of them. For patients with closed antibody deficiency, treatment can help improve the success rate of embryo implantation. However, it is important not to ignore the other causes and to use the abnormalities of closed antibodies to explain all cases of recurrent implantation failure.