¹Department of Hematopoietic Stem Cell Transplantation, Affiliated Hospital to Academy of Military Medical Sciences, Beijing, People's Republic of China

Correspondence: Dr H Chen, Department of Hematopoietic Stem Cell Transplantation, Affiliated Hospital to Academy of Military Medical Sciences, No. 8, East Street, Fengtai District, Beijing 100071, People's Republic of China. E-mail: chenhu217@yahoo.com.cn

Received 29 October 2007; Revised 30 November 2007; Accepted 4 December 2007; Published online 10 January 2008.

Abstract

In this open-label randomized clinical trial, HLA-identical sibling-matched hematopoietic stem cells (HSC) were transplanted (non-MSCs group, n=15) or cotransplanted with mesenchymal stem cells (MSCs) (MSCs group, n=10) in hematologic malignancy patients. The median number of MSCs infused was 3.4 10⁵ kg^-1 (range, 0.3–15.3 10⁵ kg^-1). MSCs infusions were well tolerated. The median time to neutrophil engraftment (absolute neutrophil count >0.5 10⁹ l^-1) was 16 days for MSCs group and 15 days for non-MSCs group. The median time to platelet engraftment (platelet count >50 10⁹ l^-1) was 30 and 27 days, respectively. Grades II–IV acute graft-versus-host disease (GVHD) was observed respectively, in one (11.1%) and eight (53.3%) evaluable patients. Chronic GVHD was found in one (14.3%) and four (28.6%) evaluable patients. The number of patients who relapsed were six (60.0%) and three (20.0%), and the 3-year disease-free survivals were 30.0 and 66.7%, respectively. Thus cotransplantation of MSCs and HSCs may prevent GVHD, but the relapse rate is obviously higher than the control group. We conclude that use of MSCs must be handled with extreme caution before a large-scale clinical trial is performed.