[Role of Mesenchymal Stem Cells in Preventing GVHD: A Meta-Analysis]

To evaluate the efficacy of mesenchymal stem cells (MSC) in the prevention of graft versus host disease (GVHD) after hematopoietic stem cell transplantation (HSCT).

Randomized controlled trials (RCT) were identified from PubMed (1950.1-2014.3), EMbase (1970.1-2014.3), Cochrane Central Register of Controlled Trials (CENTRAL, issue 4, 2014) of the Cochrane Library, China Biological Medicine (CBM, 1978.1-2014.3). References of retrieved articles were also identified. The quality of each RCT was evaluated by the Cochrane collaboration's tool for assessing the risk of bias. Data analysis was performed with Review Manager 5.1 to evaluate the efficacy of MSC in the prevention of GVHD after HSCT.

A total of 3 English articles involving 117 patients were included. Meta-analysis indicated that MSC did not reduce the incidence of acute GVHD and chronic GVHD (RR:0.44, 95% CI: 0.08 to 2.51, P = 0.35; RR:0.85, 95% CI: 0.54 to 1.33, P = 0.47). However, MSC did not increase occurrence of relapse and cytomegalovirus infection (RR:1.52, 95% CI:0.63 to 3.68, P = 0.35;RR:1.05, 95% CI:0.72 to 1.53, P = 0.78). Finally, MSC did not improve overall survival rate of patients received HSCT (RR:1.06, 95% CI:0.79 to 1.43, P = 0.71).

MSC may have a preventive effect on GVHD in patients undergoing HSCT. However, the evidence is weak due to the small sample sizes. Thus, a reliable conclusion about the preventive effect of MSC on GVHD at the moment has not been made, further larger, high quality, randomized and controlled trials are warranted.