The function of spontaneous T suppressor cell (STs) of peripheral blood was detected in 17 patients with acute schistosomiasis japonica, 14 cases with chronic schistosomiasis and 25 patients with advanced schistosomiasis. The subset of T cell were simultaneously phenotyped in all cases except 10 patients with advanced schistosomiasis. Among the patients with acute schistosomiasis the rates of OKT3 + (pan T cell), OKT4+ (helper T cell) and OKT8 + (suppressor/cytotoxic T cell) were all significantly increased, and the function of STs was normal. In chronic and advanced schistosomiasis, the rate of OKT8 + T cell was raised, the rate of OKT3+ T cell and ratio of OKT4+/OKT8+ were statistically reduced, and the function of STs was significantly increased. The rate of OKT8+ T cell was negatively correlated with the function of STs in acute schistosomiasis, whereas in chronic and advanced rchistosomiasis, the rate of OKT8 + T cell had significant positive correlation with STs function while OKT4 +/OKT8 + had significant negative correlation with this function. The results indicate that the cellular immune response is increased in patients with acute schistosomiasis and down regulated in patients with chronic and advanced schistosomiasis. The function of T suppressor cell and the subset of T cell may play an important role in the immunoregulation of patients with schistosomiasis japonica.

Activity of IL-1 produced by peripheral blood monocytes stimulated with lipopolysaccharide in vitro was detected from 17 acute cases, 14 chronic cases and 19 advanced cases of schistosomiasis japonica. It was found that the level of IL-1 was significantly increased and positively related to the body tempereture in the group with acute schistosomiasis. The activity of IL-1 was statistically reduced in the chronic and advanced groups, especially in the latter. After inhibiting the synthesis of prostaglandin with indomethacin, the level of IL-1 was significantly increased in three groups of patients, but no apparent change in the normal contro group. The results indicate that IL-1 may play an important role in inducing the inflammatory reaction in patients with acute schistosomiasis japonica and in the immunoregulation in the chronic stage. The changes of IL-1 activity in patients with schistosomiasis japonica may be closely related to prostaglandin.