Effects of Nocardia rubra cell wall skeleton on lymphocyte subsets in former poison gas factory workers

Peripheral blood lymphocyte subsets were determined in former workers of the Okunojima Poison Gas Factory (poison gas workers) having a high incidence of lung cancer, and the effect of administration of Nocardia rubra cell wall skeleton (N-CWS) was studied. In poison gas workers not receiving N-CWS, both the percentage and absolute number of Leu-2a+ cells were significantly increased as compared with normal controls, while both the percentage and absolute number of Leu-7+ cells as well as the Leu-3a/Leu-2a ratio were significantly decreased. In poison gas workers receiving N-CWS, the percentage of Leu-2a+ cells was significantly decreased when compared with poison gas workers not receiving N-CWS, while the percentage of Leu-1+ cells and both the percentage and absolute number of Leu-7+ cells as well as the Leu-3a/Leu-2a ratio were significantly increased. When N-CWS was administered to poison gas workers, the percentage of Leu-2a+ cells significantly decreased, with a minimum two weeks after administration, while the percentage of Leu-3a+ and the Leu-3a/Leu-2a ratio significantly increased and the percentages of Leu-1+ and Leu-7+ cells also increased. Furthermore, the absolute number of Leu-3a+ cells increased markedly with a peak two weeks after administration. The absolute numbers of both Leu-1+ cells and Leu-7+ cells as well as total lymphocytes also significantly increased, but that of Leu-2a+ cells showed hardly any change. It is considered that a single administration of N-CWS transiently corrects the abnormality of lymphocyte subsets, and that repeated administration of N-CWS once every three months may maintain the lymphocyte subsets of poison gas workers at normal levels.