Treatment of a patient with severe cytomegalovirus (CMV) infection after haploidentical stem cell transplantation with donor-derived CMV-specific T cells

Objectives: Cytomegalovirus (CMV) infection is one of the most common complications in allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients. The classic antiviral treatments have shown clinical efficacy but are often associated with drug resistance. Reconstitution of CMV-specific cellular immunity is essential in controlling CMV infection; therefore, adoptive transfer of CMV-specific T cells is a promising treatment option. We treated a patient with a multidrug resistant CMV infection after haploidentical HSCT with CMV-specific T cells. Methods: The T cells were derived from the HSCT donor who was CMV seropositive. We generated the T cells by a short-term Good Manufacturing Practice (GMP) grade protocol in which a leukapheresis product of the HSCT donor was stimulated with the immunodominant antigen pp65 and interferon-γ secreting cells were isolated. A total of 5 × 105 T cells were administered to the patient within 30 hours after leukapheresis. Results: The patient was closely monitored for reconstitution of antiviral T cell immunity and viral replication after adoptive T cell transfer. We observed an in vivo expansion of both CD4+ and CD8+ CMV-specific T cells associated with a significant decrease in viral burden and clinical improvement. Conclusion: This case report further supports the feasibility and effectiveness of adoptive donor T cell transfer for the treatment of drug resistant CMV infections after allo-HSCT