Abstract: Objective To investigate whether the tendency of Th1/Th2 cell in peripheral blood associatied with different immune states in early stage of allogeneic orthotopic rat liver transplantation . Methods Allografted rats were divided to three groups(each group n=36): syngeneic control(group A), the group of allograft treated with CsA 2mg kg-1.d-1(group B) and allograft (group C). At post-transplantation day of 1,3,5,7,14, six rats of each group were respectively sacrificed to harvest allografted liver for pathological , percentage of CD4+CD45RC± T cell subsets in peripheral blood of recipient by flow cytometry , and additional subgroups (n=6) for observation of survival time. Results (1)The survival time of both group A and group B were significantly longer than that of group C (>100day vs 34.3 3.6days, p<0.01).(2)Apart from 1 day, the rejection grades were higher in the group C and B than that in group A and there were significant differences between the two groups（p<0.05 or<0.01）. (3)From third day to fourteenth day post-transplantation, the ratio of CD4+CD45RC+ percentage with CD4+CD45RC- percentage was significant higher in group C than that in group B and group A（p<0.05 or 0.01）.（4）There was negative correlation between ratio of CD4+CD45RC+%/CD4+CD45RC-% and rejection grades（r=-0.565，p<0.01）, but positive correlation existed between ratio of CD4+CD45RC+%/CD4+CD45RC-% and rejection grades（r=0.745,p<0.01）。Conclusions The ratio of Th1/Th2 cell in peripheral blood has different changes according to different immune states in early stage of allogeneic orthotopic rat liver transplantation .

Key words: ] allograft liver transplantation, Th1/Th2, ciclosporin A