Dynamic change of peripheral immune cell subsets in living-related kidney transplant patients

Objective To observe the dynamic change of peripheral immune cell subsets in living-related kidney transplant (LRKT) recipients.Method Sixteen de novo LRKT recipients were enrolled in this study.The induction therapy was given (anti-CD25 monoclonal antibody),and the maintenance immunosuppressive regimen consisted of tacrolimus,mycophenloate mofetil and steroids.Subpopulations of T cells,B cells and NK cells as well as the expression of relative cell surface molecules were monitored by using flow cytometry at multiple time points before/after transplant.Examination data prior to transplant was defined as baseline level.Results The proportion of T cells was decreased within 3 days after transplantation,and then increased steadily to 1.2 times of the baseline at month 6.The CD25 expression in CD4+ and CD8 + T cells and the proportion of CD4+CD25highCD127low regulatory T cells were decreased significantly within three months post-transplant,and recovered to the baseline at month 6.CD19+ B cells were significantly increased by 1.8-2.1 times within one month post-transplant,and recovered to the baseline at month 3.CD5+ CD19+ B cells were decreased steadily after transplantation and dropped to 45％ at month 6.Memory B cells were increased gradually by 1.3 times after transplantation.The BAFF-R expression in B cells maintained at high level (91.7％-97.9％) within six months post-transplant.The germinal center (GC) founder cells (IgD+ CD38++) and GC B cell subpopulation (IgD-CD38++) were consistently decreased after transplantation.NK cells were decreased gradually to 44％ at month 6.NKG2A/NKG2D was increased significantly by 2.4-7.1 times within six months.Conclusion The CD25 expression in effector T cells and regulatory T cells began to recover after three months post-transplant.B cells proportion was significantly increased early after transplant without inhibition of activation.NK cells were decreased dramatically after transplantation and the killer function might be impaired.Dynamic monitoring of immune cell subsets may facilitate estimating immune risk of rejection and infection. Key words: Kidney transplantation;  Anti-CD25 monoclonal antibody;  Induction therapy; Immune monitoring