Infusion of autologous Epstein-Barr virus (EBV)–specific cytotoxic T cells for prevention of EBV-related lymphoproliferative disorder in solid organ transplant recipients with evidence of active virus replication

Epstein-Barr virus (EBV)-associated posttransplantation lymphoproliferative disorders (PTLDs) are a well-recognized complication of immunosuppression in solid organ transplant recipients. The reported therapeutic approaches are frequently complicated by rejection, toxicity, and other infectious pathologies, and overall mortality in patients with unresponsive PTLD remains high. Thus, low-toxicity treatment options or, preferably, some form of prophylactic/preemptive intervention are warranted to improve PTLD outcome in this setting. We assessed whether transfer of EBV-specific cytotoxic T lymphocytes (CTLs) generated in vitro from the peripheral blood of allograft recipients receiving immunosuppression could increase EBV-specific killing in vivo without augmenting the probability of graft rejection. Autologous EBV-specific CTLs were generated for 23 patients who were identified as being at risk of developing PTLD through the finding of elevated EBV DNA load. Of the 23 patients, 7 received 1 to 5 infusions of EBV-specific CTLs. CTL transfer was well tolerated, and none of the patients showed any evidence of rejection. An increase of the EBV-specific cytotoxicity was observed after infusion, notwithstanding continuation of immunosuppressive therapy. EBV DNA levels had a 1.5- to 3-log decrease in 5 patients, whereas in the other 2 graft recipients CTL transfer had no apparent stable effect on EBV load. Our data suggest that the infusion of autologous EBV-specific CTLs obtained from peripheral blood mononuclear cells recovered at the time of viral reactivation is able to augment virus-specific immune response and to reduce viral load in organ transplant recipients. This approach may, therefore, be safely used as prophylaxis of EBV-related lymphoproliferative disorders in these patients, following a strategy of preemptive therapy guided by EBV DNA levels.