[Malnutrition as a cause of decreased NK activity in cancer patients].

In this work we investigated the effects of malnutrition on the immune response in neoplastic patients. We studied the basal NK activity of 34 neoplastic malnourished patients and 10 neoplastic not malnourished patients and a control group of blood donors, by a standard 51 Cr release assay against K562 cells. We observed that the neoplastic malnourished patients have a defective NK activity in spite of a normal number of NK cells, as ascertained by HNK-1 monoclonal antibodies. The reduced NK activity of the neoplastic malnourished patients is only partially restored by rIFN alpha 2a but is normalized by rIL-2 stimulation. We also found that the endogenous IL-2 production from some of these patients is slightly reduced as compared to controls. On the contrary, there are no significative differences between the neoplastic not malnourished patients and blood donors, as concerns the NK activity. These results suggest that nutritional status plays a very important role in the maintenance of an efficient immune response in neoplastic patients.