Association of immunosuppressive maintenance regimens with posttransplant lymphoproliferative disorder in kidney transplant recipients.

Background. The association of immunosuppressive regimens (ISRs) with posttransplant lymphoproliferative disorder (PTLD) may be related with the Epstein-Barr virus (EBV) recipient serostatus. Methods. We selected primary kidney transplant recipients from Organ Procurement Transplant Network/United Network for Organ Sharing database (2000-2009) who were discharged with a functioning graft and were receiving an ISR including an antiproliferative drug and a calcineurin inhibitor as follows: mycophenolate mofetil (MMF)/mycophenolate sodium+tacrolimus (TAC), MMF+cyclosporine A (CsA); mammalian target of rapamycin inhibitor (mTORi)+TAC; and mTORi+CsA. Adjusted risks of PTLD, rejection, death, and graft failure were examined in all recipients and compared between EBV+ nd EBV-recipients. Results. Of 114,025 recipients, 754 developed PTLD (5-year incidence of 0.84%). Adjusted hazard ratio for PTLD was 4.39 (95% CI: 3.60 -5.37) for EBV-versus EBV+recipients; and 1.40 (95% CI: 1.03-1.90) for mTORi+TAC, 0.80 (95% CI: 0.65-0.99) for MMF+CsA, and 0.90 (95% CI: 0.57-1.42) for mTORi+CsA, versus MMF+TAC users. In EBV-recipients, hazard ratio for PTLD was 1.98 (95% CI: 1.28 - 3.07) for mTORi+TAC, 0.45 (95% CI: 0.28-0.72) for MMF+CsA, and 0.84 (95% CI: 0.39-1.80) for mTORi+CsA users versus MMF+TAC. No difference was seen in EBV+recipient groups. Rejection rates were higher among MMF+CsA recipients in both EBV groups. Death and graft failure risk were increased in all EBV+ISR groups, while in EBV-these risks were only increased in mTORi+TAC group versus MMF+TAC. Conclusions. In EBV-recipients, immunosuppression with mTORi+TAC was associated with increased risk of PTLD, death, and graft failure, while MMF+CsA use was associated with a trend to increased risk of rejection, lower PTLD risk, and similar risk for graft failure when compared with MMF+TAC.