OBJECTIVETo explore the safety and efficiency of unrelated donor peripheral blood stem cells (URD-PBSC) transplantation combined with umbilical cord mesenchymal stem cells (UC-MSC).

METHODSThe clinical data of 49 patients received unrelated donor peripheral blood stem cells transplantation (URD-PBSCT) for treating hematologic malignancies were retrospectively evaluated, including 12 ANLL, 17 ALL, 18 CML and 2 MDS. Out of them, 22 patients received the URD-PBSCT combined with UC-MSC and 27 patients received only URD-PBSCT. The average number of infusing UC-MSC was 1.0 × 10⁶/kg in the UC-MSC+URD-PBSCT group.

RESULTSAs compared with URD-PBSCT group, in UC-MSC+URD-PBSCT group the median recovery time of neutrophilc granulocytes was shorter (12 d vs 15 d) (P = 0.041), the incidence and severity of chronic graft versus host disease (cGVHD) were lower (20.0% vs 51.9%) (P = 0.026) (5.0% vs 33.3%) (P = 0.040), the incidence of CMV infection after transplantation was higher (81.8% vs 51.9%) (P = 0.028). In addition to these, the differences were not statistically significant in term of implantation level, PLT reconstitution, aGVHD, lung infection, hemorrhagic cystitis, 1-year relapse and survival between the 2 groups (P > 0.05).

CONCLUSIONThe transplantation of URD-PBSC combined with UC-MSC is effective and safe. The speed of neutrophils reconstitution is faster. The incidence and severity of cGVHD are lower, but the attention should be paid to prevent the CMV infection.