Aim: To explore the regulatory function of FK506 and CsA on CD4/CD8 T lymphocyte subgroups and co-stimulators on them.
Methods: The fluorescein-labelled monoclonal antibodies and flowcytometer were used to determine the T-lymphocyte subgroups and the expression of CD28, CD152 and ICOS on them in allo-liver recipients treated with FK506 or CsA at the end of 2 months after transplantation and treatment. Healthy volunteers and the patients who suffered from severe hepatic diseases and would receive liver transplantation were used as controls.
Results: In disease-control group, the balance of T cell subgroups was disturbed and the expression of co-stimulators was abnormal. In liver recipients receiving immunosuppressive therapy, the expression of T-cell subgroups returned to the normal level, the expressions of CD28 and ICOS on T cells decreased significantly (P<0.05), while the expression of CD152 on T cells increased significantly (P<0.05). Between two treatment group, the expression of CD4(+)T cells and the expression of CD28 and ICOS on CD8(+)T cells in CsA-treated group were much higher than those in FK506-treated group (P<0.05), and there was no significant difference between two treatment groups in other indexes.
Conclusion: At routine blood concentration, there is some difference in the regulatory effect of FK506 and CsA on T-cell subgroups and the expression of co-stimulators on T cells. The regulatory effect of FK506 on T-cell subgroups is stronger than that of CsA. FK506 can not only inhibit the expression of positive co-stimulatory molecules CD28 and ICOS but also promote the expression of negative co-stimulatory molecule CD152, while CsA can exert its immunosuppressive effect mainly through promoting the expression of CD152.