Dr. George Ioannidis

Director GONIMOTIS Reproductive Centre
v. Scientific Director Institute of LIFE MHTERA Hospital IVF Unit

Dr. Alexandra Georgakopoulou

Scientific Director GONIMOTIS Ultrasound Centre
Scientific Collaborator MHTERA Hospital Fetal Medicine Unit.


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Tel:    +30 210 7222442-443
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Email:  info@gonimotis.gr


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Home  /  Fertility  /  NK cells & lymphocyte immunization therapy


NK cells & εμβόλια λεμφοκυττάρων

Natural killer cells (NK cells) are immune cells that help fight body infections. There is the theory – belief that NK cells can attack the embryo considering it as the attacker and kill it by miscarriage. Scientists in favor of this theory recommend the measurement of NK cells in the blood and if their count is found high, the use of drugs to suppress the action of these cells. However, the majority of the medical community worldwide is questioning this approach, because it has not shed light on whether the NK cells in the blood can attack the embryo and lead to miscarriage.


NK-parental cells

NK cells circulating in the blood are a type of lymphocytes (immune cell). But there are also different forms of NK cells found on the uterine surface lining the uterine cavity, which resemble blood NK cells and are called uterine NK cells.

These cells present significant differences between them:

NK maternal tissues are not found in the blood, but only appear in the lining of the uterus during pregnancy while the embryo is already implanted. Therefore, measuring the NK cells in the blood, does not give us any clues about the uterine NK.

There is no evidence that maternal NK are damaging and can turn against the placenta or the embryo.

But what do the NK cells of the uterus do? They have been shown to appear on the uterine wall during embryo implantation and during the first months of pregnancy and appear to help placental attachment to blood vessels and the creation of a healthy blood supply line for the embryo.

Supporters of KN cell theory believe that by measuring blood levels of NK, if they prove to be high, they can kill the embryo. There is no strong evidence in the world literature that the number and activity of NK cells in the blood can be correlated with the number and activity of uterine NK cells.

Therefore, examining NK cell levels in the blood and their association with uterine NK is partially arbitrary.

In addition, there are no internationally recognized normal values for NK cells in the uterus. It is therefore wrong to collect the blood of the period to determine the NK cells in it. There is no correlation with venous blood and the measurements are arbitrary.


Immune therapies

These are therapies that aim at “suppressing NK cells” and include:

  • High doses of cortisone (corticosteroids):

The American Committee for the Safety of Medicines reports that corticosteroids taken during pregnancy may increase the risk of residual growth of the embryo. A large Canadian study has also shown that the use of cortisone in the first trimester of pregnancy has not prevented early miscarriages, while increasing the risk of preeclampsia and diabetes in pregnancy and premature birth.

  • Intravenous administration of immunoglobulin (immunization)

These therapies are not approved by the World Health Organization, as there is no generally accepted scientific explanation for any benefits they may have in reproductive medicine.

This immunization (not vaccination) consist of the male partner’s serum and lymphocytes to supposedly immunize the woman against the embryos from his semen. If this is not successful some people even go on to use blood from other women or other men.

The use of these “vaccines” can lead to side effects such as headache, muscle aches, fever, chills, back pain, thrombosis (blood clots), kidney failure and allergy. If donor blood has been used, there is a risk of infection with hepatitis, AIDS or CJW disease (mad cow disease).

Both the Royal College of Obstetricians and Gynecologists (RCOG)link] and the British Fertility Society (BFS) [link] have published guidelines on immune therapies and the lack of documentation on their implementation. Both bodies conclude that the manufacture and use of these therapies:

Has not well documented scientifically

Is not internationally certified

Has no statistically proven results

It is only allowed under certified research protocols where patients are informed about the risks and sign a formal consent by taking responsibility for possible side effects


What do I advise you?

Couples suffering from repeated miscarriages or repeated incomplete IVFs are vulnerable to undergo “treatments” that are not sound and scientifically acceptable.

I would advise you to be very careful and cautious when someone is suggesting such treatments to you. My personal view is that only a very limited number of couples could benefit from this treatment