NK or Natural Killer Cells
There are some controversies regarding the NK cells and its treatment. The controversies are mainly based on 3 issues:-
The link between NK cells and miscarriages and fertility – There is now enough evidence from work done by our research group and others that demonstrates that link.
The type of test – Even the most opposed to the theory of NK cells now believe in the possible link of NK cells to pregnancy loss or fertility problems. However, there seem to be some confusion regarding the type of tests to be carried out. It is true that peripheral blood NK count may not be an accurate reflection of the environment inside the womb, however there is some good evidence on the link between peripheral blood NK activity and miscarriages and fertility issues. There are some assumption that an endometrial sample may be more accurate but there are even more concerns about those tests. Every time a womb menstruates, that particular endometrium with all its NK cells are shed and therefore, next cycle the number of NK cells may vary. Also, it is impossible to achieve a pure endometrial sample with it being blood stained, which means that the sample will contain endometrial lining as well as blood NK cells which confuses the result.
The immune therapy treatment – There is more and more emerging evidence that immune therapy improves pregnancy and fertility outcome. In our hands, we have seen high success rate with the use of prednisolone as well as other types of therapy such as intralipids. It is not a coincidence that the most successful IVF units have the use of immune therapy as the common factor.