Flow cytometry in detection of abnormalities of natural killer cell

The population of natural killer (NK) cells is very heterogeneous and plays a role in the immune system. Several NK cells subpopulations are recognized, differing in phenotype, cytokine release and cytotoxic ability. Different expression of biologically relevant molecules on the surface of NK cells may indicate their multiple functions. The activity of NK cells has mainly to do with their cytotoxic nature. A complete analysis of NK cells function requires application of many tests because a defect may be present at different stages of the cytotoxic process, from signal transduction through lysosome degranulation to target cells destruction. Flow cytometry is actually one of the best methods for the identification of NK cells and tracking their defects.