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.