Natural Killercell Deficiency (NKD)

Natural Killer Cell Deficiency (NKD) alone is a rare disorder of innate immune system.Isolated NK cell is deficiency can be classical or functional. In classical Natural killer cell deficiency, NK cells are ≤1% of peripheral blood lymphocytes whereas functional NK cell deficiency is associated with decrease ability to perform its function. NKD makes patients more prone to viral infections (especially with Herpes, Varicella zoster, Cytomegalo & Ebsteinbarr viruses) and malignancies. This defect should be suspected in patients with repeated fever and chest infections, when all other causes of primary immunodeficiency are ruled out. A 2-years-female patient with repeated chest infections, on off fever since the age of 7 months with very poor to antibiotics and negative blood culture on several occasions. Lymphocyte subset analysis repeated at a gap of two months and a final diagnosis of Natural killer cell deficiency was established.