Clinical stage-depending decrease of NK cell activity in multiple myeloma patients.

Natural killer cells, as an important subpopulation of cells of the innate immune system have an essential role in defense of the rise and spread of malignancy. These cells have a CD3-CD16 + CD56+ phenotype and they are functionally defined by their ability to lyses tumor cells. We here show that decrease of NK cell activity was significantly associated with advanced clinical stage, increased lactate dehydrogenase (LDH), percentage infiltration of bone marrow with plasma cells, and beta-2 microglobulin. The patients with higher NK cell activity at presentation after receiving VAD protocol have better cumulative survival in comparison with those with low NK cell activity.