Nk Cell Panel - CD3, CD16 / CD56

Natural killer (NK) cells are a part of your immune system that kills foreign pathogenic invaders and neutralises their harmful reactions. Every organ has plenty of NK cells, including the reproductive organs. The natural killer cells in the uterus play an important role when a woman is pregnant.

During the plantation of the embryo to the uterine wall, these cells cause inflammation to assist in proper attachment. However, excess or lack of NK cells can cause infertility or a miscarriage during pregnancy.

A natural killer cell test is suitable for identifying chronic infections like HIV-1 and hepatitis C virus. In this test, the surface molecules known as cluster of differentiation (CD) play a primary role in determining the immune response. These molecules are responsible for cell-cell communication during the immune reaction.

Since there are several CD molecules, each is considered a marker for a particular health condition. CD3, CD16 and CD56 are the markers for inflammation and tumour response, respectively.

As per multiple studies, the average percentage of CD16/CD56 NK cells in the body varies from 5% to 29%. Hence, if the NK cell panel test reflects more than 12% of CD cells, it indicates miscarriage or infertility in women. Similarly, the NK cell test shows a range between 2% and 38% during chronic infections.

Apollo 24|7 has an explicit panel for the NK cell test that is taken under the following circumstances:

• To identify or monitor the progress of an HIV infection
• To observe the problems related to immune deficiency with NK cell defect
• NK cell lymphocytosis 
• Before or after solid organ transplantation 
• To assess the reconstitution of the immune system after bone marrow transplantation or hematopoietic cell transplantation

Natural killer cells are not a homogenous set of molecules. The most common combination of surface markers includes CD3, CD16, and CD56. These molecules are responsible for producing the following types of reactions in the body:

• CD3: It is a T-cell receptor that has a significant role in activating T-cell-mediated immune response. It transduces the signal after recognising the antigens and activates T-lymphocytes. 
• CD16: This is an Fc receptor that facilitates antibody-dependent cellular cytotoxicity by binding to several antibodies. It is mainly responsible for tumour surveillance and low affinity toward IgG. 
• CD56: This neural cell adhesion molecule indicates inflammation in particular sites. These are homing markers for the inflammation, i.e., they rush immediately to the site of inflammation and are easier to test. 

NK cell test identifies ongoing viral infection and its effects due to a lack of sufficient natural killer cells. 

Frequently asked questions

How are NK cells test helpful in identifying a women’s reproductive health?

Natural killer cell test identifies the increasing or decreasing levels of NK cells in a women’s body. The concentration is high during menstruation and crosses the optimum amount during the implantation phase of pregnancy. Sometimes, when the amount of NK cells is exceptionally high, the immune system identifies the foetus as a foreign substance and starts attacking it. This leads to miscarriages and unsuccessful conception despite proper fertilisation. NK cell test panel identifies these fluctuations and makes them easier to manage.

Is any special preparation required for the natural killer cell test?

The test does not require special preparations because it involves a simple blood examination. The phlebotomist draws a minimum of 2 ml of blood from the vein in a dedicated test tube to avoid blood clotting. The service provider needs to clean the area before and after drawing the blood to prevent any infection on the surface.

What does the NK cells test indicate?

Natural killer cell test indicates your body’s immune reaction level. It could be high or low, depending on your infection. Moreover, to improve your condition, you might need an intervention of immune therapy. The medication usually involves a certain kind of immunosuppressive drug that might reduce the level of NK cells and inflammation.

Does a high level of natural killer cells in the NK cell test mean permanent infertility?

No. The test results are just an assessment to start medication. A few miscarriages or failed conceptions do not imply permanent infertility.

What is the role of CD16 in HIV infection?

CD16 is an important biomarker of HIV-1 infection. These express higher levels of CCR5. Hence, higher levels of CD16 indicate the presence of chronic viral disease and allow the physicians to start the treatment.

Why does the NK cell level affect a woman's reproductive health?

The abnormal levels of NK cells in the natural killer cell test indicate the presence of an autoimmune disease that causes recurrent miscarriages. The treatment usually involves medication such as prednisone or intravenous immunoglobulin.