Abstract: 【Abstract】 Objective To investigate the variation of lymphocytes and cytokines in patients with cystic echinococcosis （CE）. Methods 80 CE patients who were diagnosed for the first time （60 of Han and 20 of Uygur nationality）， and 37 patients who were to accept the second surgical operation（24 Han and 13 Uygur nationality） were included in the study. The peripheral lymphocytes of patients before operation were analyzed by flow cytometry （FCM） to detect T and B lymphocytes， NK cells bearing surface markers， as well as Th1 cytokine IFN-γ and Th2 cytokine IL-4 in the cytoplasm of lymphocytes. 179 healthy persons served as control. Results In the group of Han patients who were diagnosed for the first time， the percentage of total T cells（CD3⁺） was lower than the control （P<0.05）， while among patients accepting the second operation， the ratio of total T cells showed no difference to the control. For the helper T cells （CD3⁺/CD4⁺）， NK cells （CD3⁺/CD16，56⁺） and B cells （CD3-/CD19⁺）， their ratio were significantly lower in both groups than the control （P<0.01）， but their cytotoxic T cells （CD3⁺/CD8⁺） were higher than the control. In Uygur patients diagnosed for the first time， B cell ratio was lower than that in control （P<0.05）. The NK cell level in both groups of patients was lower than control （P<0.01 and P<0.05 respectively）. The level of Th0 and Th1 showed no statistical difference among the three groups（P＞0.05）. The Th2 level was significantly higher in the first diagnosed patients than control （P<0.01）， but no statistical difference between the group with the second operation and the other two groups. Conclusions The immune status of echinococcosis patients is inhibited and the level of Th1 and Th2 shows difference in the first and second operation groups.

Key words: Cystic echinococcosis, Lymphocyte immunophenotyping, Flow cytometry