Changes in T cell subsets and T suppressor cell function and their relationship in human schistosomiasis japonica.

The function of spontaneous T suppressor cell (STs) of peripheral blood was examined in 56 patients with schistosomiasis japonica at various stages. The subsets of T cell were simultaneously phenotyped in 46 cases. The percentages of CD3+ (pan T cell), CD4+ (helper/inducer T cell) and CD8+ (suppressor/cytotoxic T cell) in patients with acute schistosomiasis japonica were significantly higher than those in the normal controls. In patients with chronic and advanced schistosomiasis japonica, the percentage of CD8+ T cell and the function of STs were greatly increased, but the percentage of CD3+ T cell and the ratio of CD4+/CD8+ were obviously reduced. All of these markers changed more significantly in patients with advanced schistosomiasis japonica. The percentage of CD8+ T cell in patients with acute schistosomiasis japonica was negatively correlated with the function of STs. In patients with chronic and advanced schistosomiasis japonica the percentage of CD8+ T cell was correlated positively and the ratio of CD4+/CD8+ negatively with the function of STs. The results indicated that the cellular immunity was significantly increased in cases of acute schistosomiasis japonica and decreased in those with chronic or advanced schistosomiasis japonica. The increased CD8+ T cell may be principally cytotoxic T cells in patients with acute schistosomiasis japonica, but suppressor T cells in patients with chronic and advanced schistosomiasis japonica. The subsets of T cells and the function of T suppressor cells may play an important role in the immunoregulation of schistosomiasis japonica.