The effect of induction therapy on established CMV specific T cell immunity in living donor kidney transplantation.

Cytomegalovirus (CMV) infection influences both short and long term outcomes in immunosuppressed organ transplant recipients. The aim of this study was to evaluate the effect of different induction immunosuppression regimens on CMV specific T cell response in patients with already established CMV immunity. In 24 seropositive living donor kidney recipients, the frequency of CMV specific T cells was determined by ELISPOT (Enzyme-Linked ImmunoSpot) assay prior and 6 months after transplantation. Recipients' peripheral blood mononuclear cells were stimulated with immediate-early (IE1) and phosphoprotein 65 (pp65) CMV-derived peptide pools and the number of cells producing interferon gamma (IFN-gamma) was assessed. Patients received quadruple immunosuppression based either on depletive rabbit antithymocyte globulin (rATG) or non-depletive basiliximab induction and tacrolimus/mycophenolate mofetil/steroids. Patients with rATG induction received valgancyclovir prophylaxis. No effects of different induction agents on CMV specific T cell immunity were found at sixth month after kidney transplantation. There were no associations among dialysis vintage, pretransplant CMV specific T cell immunity, and later CMV DNAemia. Similarly, no effect of CMV prophylaxis on CMV specific T cell immunity was revealed. This study shows no effect of posttransplant immunosuppression on CMV specific T cell immunity in living donor kidney transplant recipients with CMV immunity already established, regardless of lymphocyte depletion and CMV prophylaxis.