CD8~+CD28~-T-suppressor Cells Contributes To Maintaining Long-term Stable Graft Function After Liver Transplantation

Background:Liver transplantation(LT)is the only effective treatment for end-stage liver disease.The application of immunosuppressive agents after transplantation resulted in a significant reduction in the incidence of graft rejection compared with that before.Liver transplantation has achieved good near-term survival rate,but its long-term effect is still unsatisfactory,mainly due to the life-long application of immunosuppressants.Early identification of tolerable states in recipients by immune surveillance and even the initiation of tolerance by interventions are the focus of current researches.Aim:CD8+CD28-T cells(CD8Ts)exert immunosuppressive effects in various autoimmune diseases.The current study was designed to investigate the role of defects in CD8Ts in liver transplantation(LT).Material and methods:1.The tacrolimus concentration was detected with enzyme-linked immune sorbent assay.2.The proportion of CD8Ts in peripheral blood was determined by flow cytometry.3.The demographics and clinical information was collected from the data bank of LT.4.The data o.f experiments were presented as frequency or mean with SD,and further analyzed with SPSS 19.0.Results:1.The mean proportion of CD8Ts was 23.39%in recipients with stable graft function and 16.64%in those with graft dysfunction following LT compared with 19.86%in the healthy cohort.2.After receiving enhanced immunosuppressive therapy;patients in the rejection group who achieved recovery of graft function showed an increase in the proportion of CD8Ts(from 17.39%to 25.55%),but those in the group with refractory graft dysfunction showed no significant change(12.49%to 10.30%).3.Furthermore,in the first year after LT,recipients longer removed in time from the LT date exhibited a higher proportion of CD8Ts.4.Patients benefited most from tacrolimus concentrations of 5-10 ng/ml in the first year after LT and 0-5 ng/ml thereafter.5.The ?CD8Ts(CD8Ts proportion-CD8+CD28+T cells proportion)proportion was significantly higher in the recipients with stable graft function than those with graft dysfunction.Conclusion:1.High Frequency of CD8Ts prevents rejection and contributes to long-term maintenance of stable graft function after LT.2.High Frequency of CD8Ts is a potential method to reduce immunosuppressant dosage and even induce tolerance.