Objective: To explore the efficacy and safety of expanding cytomegalovirus specific cytotoxic T lymphocytes (CMV-CTL) in vitro on refractory cytomegalovirus (CMV) infection.
Methods: A total of twenty-eight patients with refractory CMV infection following stem cell transplant (SCT) were treated with CMV-specific T cells, of which 19 cases were from hematopoietic stem cell donors and 9 from third-party donors. In the first course, CTL was infused once or twice and the efficacy and adverse effects were evaluated. If CMV infection relapsed after complete remission (CR), the second course would be given.
Results: Twenty-one patients with refractory CMV viremia and seven with CMV diseases were eligible for adoptive T-cell transfer. After a median of 76 (39-321) days post-transplant, patients received a median dose of 1.0 (0.5-10.0) × 10(7) CTL infusion in the first course. All twenty-one patients with CMV viremia and four patients with CMV diseases achieved CR after using 9 (3-23) and 7 (4-18) days respecitvely. Six patients with CMV viremia and one with CMV disease received the second course after recurrence. Another four patients with viremia and one with CMV disease had reached CR again. Five patients exhibited graft-versus-host diseases (GVHD), all experiencing mild to moderate skin involvement. Six patients died of CMV infection and 2 of other transplantation-related complications.
Conclusion: Our preliminary results have shown that CMV-CTL infusion is effective against refractory cytomegalovirus infection following SCT, but therapeutic schedule still needs to be improved in further study.