NK Cells Absolute Unit Converter

Natural killer (NK) cells are a type of white blood cell that belongs to the innate immune system. Unlike T cells and B cells, NK cells can recognize and destroy virus-infected cells and abnormal cells without needing prior exposure to them.

NK cells typically make up about 5–20% of circulating lymphocytes. The absolute count measures the total number of NK cells per unit volume of blood, rather than just their percentage among lymphocytes.

They are identified in the lab as CD3-negative, CD56-positive lymphocytes, sometimes also expressing CD16. The absolute count gives a more reliable picture of NK cell status than the percentage alone, since the percentage can shift when other lymphocyte populations change.

NK cells develop in the bone marrow from hematopoietic stem cells through common lymphoid progenitors. They mature in the bone marrow and secondary lymphoid tissues before entering the bloodstream.