Effects of Nocardia rubra cell wall skeleton on interleukin 2 production and lymphocyte proliferation in former poison gas factory workers.

Phytohemagglutinin (PHA)-induced interleukin 2 (IL-2) production and lymphocyte proliferation were measured in former workers of the Okunojima Poison Gas Factory (poison gas workers), who have a high incidence of lung cancer, and the efficacy of administration of Nocardia rubra cell wall skeleton (N-CWS) was studied. In comparison with normal controls and poison gas workers receiving N-CWS, lymphocyte proliferation in poison gas workers not receiving N-CWS showed a significant decrease, while IL-2 production showed a slight though not statistically significant decrease. When N-CWS was administered to poison gas workers, IL-2 production and lymphocyte proliferation were significantly elevated, with a peak two weeks after administration. N-CWS, by elevating IL-2 production of lymphocytes, is considered to have improved the depression of lymphocyte proliferation.