Nutrition and cellular immunity in hospital patients.

1. The interrelations between nutritional and cellular immune function measurements were studied in seventy patients suffering from various degrees of malnutrition. They included patients with liver disease, inflammatory bowel disease, neoplastic disease, neurological patients, post-operative surgical patients and patients with respiratory problems. 2. Nutritional measurements included: anthropometry, serum proteins, various vitamins and trace elements, and a prognostic nutritional index (PNI) was calculated. 3. Immunological measurements included: (1) natural killer (NK) cell activity, (2) antibody-dependent cellular cytotoxicity (ADCC), (3) lymphocyte proliferation in response to the mitogens concanavalin A (Con A), phytohaemagglutinin (PHA) and pokeweed mitogen (PWM) in both AB and autologous serum. 4. There was no association between anthropometric measurements and tests of immune function. 5. The lymphocyte proliferation in response to mitogenic stimulation in the malnourished patients was depressed in autologous serum compared with the response of the same lymphocytes in pooled AB serum. The lymphocyte proliferation in response to Con A correlated with transferrin in autologous serum (r 0.46, n 49, P less than 0.01) and to a lesser extent in AB serum (r 0.33, n 51, P less than 0.05). There was a difference in the Con A-stimulated tritiated-thymidine uptake between patients with low and normal serum zinc levels (P less than 0.05) for cultures performed in autologous serum, but not AB serum. 6. There was a significant correlation between NK cell activity and vitamin C (r 0.43, n 60, P less than 0.01). There was no relation between nutritional measurements and ADCC or the lymphocyte response to stimulation with PHA or PWM. 7. The results suggest that the severity of overall malnutrition does not influence several different aspects of the cellular immune response. However, the results do suggest that certain individual nutrients, particularly vitamin C and Zn, do influence the immunoreactivity of different lymphocyte subpopulations.