Changes in peripheral blood Th1 and Th2 cells in rat liver transplantation under different immune statuses

In this study, early expressions of peripheral blood Th1 and Th2 cells were documented following rat liver transplantation and related to immune status. Rats were divided into 3 groups: group A (control): syngeneic transplantation (Brown Norway (BN) → BN); group B: allogeneic transplantation + cyclosporine A (CsA); group C: allogeneic transplantation (Lewis → BN). Flow cytometry was used to analyze peripheral blood CD4(+)CD45RC percentage on days 1, 3, 5, 7, and 14 following transplantation, and were compared to graft rejection pathological grades and receptor survival times. The average survival of groups A and B exceeded 100 days, which was significantly longer than that of group C (3.56 ± 34.3 days). With the exception of the first day, rejection grades were significantly higher in groups C and B compared to group A, and group C rejection grades were significantly higher than those of group B. Three days after transplantation, the CD4(+)CD45RC(+) to CD4(+)CD45RC(-) ratio of group C was significantly higher than that of groups A and B. In group B, the CD4(+)CD45RC(+) to CD4(+)CD45RC(-) ratio was negatively correlated to the rejection grade (r = -0.565, P < 0.01), whereas this relationship was positive in group C (r = 0.745, P < 0.01). In conclusion, peripheral blood Th1 was highly expressed during rejection in rat liver grafts. Peripheral blood Th2 tended to increase early under rejection inhibition with CsA, and its high expression level may correlate with long-term acceptance or tolerance of transplanted livers.