OBJECTIVETo investigate the clinical difference of cytomegalovirus (CMV) infection between HLA-matched allogeneic hematopoietic stem cell transplantation (allo-HSCT) and haploidentical hematopoietic stem cell transplantation (hi-HSCT).

METHODSThe clinical data of 83 patients who had undergone allo-HSCT were retrospectively analyzed. Out of them 50 patients underwent hi-HSCT and 33 patients received grafts from HLA-matched donors. The sera of all recipients and donors were CMV-negative before transplantation. All patients accepted myeloablative regimen without total body irradiation. PCR was performed to detect CMV in the peripheral blood twice a week after neutrophil recovery. CMV-DNA>500 copies/ml was defined as CMV viremia.

RESULTS68 patients (81.9%) were diagnosed as CMV viremia before 100 days after transplantation. The incidence of CMV infection in hi-HSCT group was 90% and significantly higher than that in HLA-matched HSCT group (69.7%) (P < 0.05). All the patients responded well to anti-CMV therapy; however, 63 cases experienced CMV reactivation. The occurrence rate of CMV reactivation in hi-HSCT group (95.6%) was comparable to that in HLA-matched HSCT group (87.0%) (P > 0.05). Univariate analysis showed that the transplantation pattern, the recovery time of peripheral neutrophils and the occurrence of acute graft-versus-host disease (aGVHD) significantly related to the episode of CMV viremia, while the sex and age of the recipients, and the recovery time of platelets did not associate with the incidence. Further analysis found that the recovery time of neutropils and platelets in HLA-matched HSCT group were greatly shorter than those in hi-HSCT group (P < 0.05). The incidence of aGVHD was comparable between two groups however, incidence of severe aGVHD was significantly higher in hi-HSCT (P < 0.05).

CONCLUSIONThe hi-HSCT is more susceptible to CMV infection, which may be related to the higher incidence of severe aGVHD and the relative delay of hematopoietic reconstruction as compared with HLA-matched HSCT.