Cytomegalovirus-specific T cells immune reconstitution after human leukocyte antigen matched sibling donor allogeneic bone marrow plus peripheral blood hematopoietic stem cell transplantation

OBJECTIVE: To investigate the regular pattern of Cytomegalovirus (CMV)-specific T cells (CTL) immune reconstitution after human leukocyte antigen (HLA) matched sibling donor allogeneic bone marrow(BM) plus peripheral blood hematopoietic stem cell (PBSC) transplantation. METHODS: CTL from seventeen patients after transplantation was detected by flow cytometry, the IFN-γ secretion ability of CTL by enzyme-linked immunospot (ELISPOT) assay, and clonal analysis of TCR Vβ subfamily by gene scan assays. The relationship between CTL reconstitution and CMV infection was studied. RESULTS: Both number and function of recipients CTL reached to normal control level at 30 d post-transplantation. The recipients achieved a high frequency CTL with IFN-γ response and restoration of T-cell receptor β (TCR Vβ) repertoire at one year post-transplantation. CTL with the central memory CD45RO(+)CD62L(+) cell phenotype expanded in PB when CMV was reactivated. The incidence of CMV reactivation was 35.83% (17.91% - 63.10%) after transplantation, and none of them developed CMV disease. CONCLUSION: After HLA matched related donor transplantation using mixed grafts, immune recovery to CMV seems to be early and fast. The incidence of CMV infection and disease are low.