[A multi-center trial of MY-1, a new biological response modifier, on the immunological parameters of postoperative gastric cancer patients].

A multi-center study was performed to clarify the immunological effects of MY-1, a new biological response modifier, on postoperative gastric cancer patients. A total of 90 patients were randomly allocated either to an MY-1 treated or an untreated group. MY-1 was given 3 times a week from the 4th postoperative day for a period of 3 weeks. Immunological parameters of the patients, such as lymphocyte subsets measured with flow cytometry using various monoclonal antibodies, blast transformation responses against PHA, ConA, and PPD, natural killer activity of peripheral lymphocytes, and skin test for MY-1 and PPD, were evaluated preoperatively, before and after MY-1 treatment. The results of the two color staining method with flow cytometry showed that the population of lymphocytes positive for both OKT8 and Leu15 antigens (suppressor cells) was statistically less, and that the population of lymphocytes positive for OKT8 and negative for Leu15 antigens (killer cells) was statistically increased in patients treated with MY-1 compared with the control group.