Efficacy and safety of mesenchymal stromal cells for the prophylaxis of chronic graft-versus-host disease after allogeneic hematopoietic stem cell transplantation: a meta-analysis of randomized controlled trials

A meta-analysis of randomized controlled trials (RCTs) was conducted to evaluate the efficacy and safety of mesenchymal stromal cells (MSCs) for the prophylaxis of chronic graft-versus-host disease (cGVHD) in patients with hematological malignancies undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). Six studies involving 365 patients were included. The pooled results showed that MSCs significantly reduced the incidence of cGVHD (risk ratio [RR] 0.63, 95% confidence interval [CI] 0.46 to 0.86, P = 0.004). Favorable prophylactic effects of MSCs on cGVHD were observed with umbilical cord-derived, high-dose, and late-infusion MSCs, while bone marrow-derived, low-dose, and coinfused MSCs did not confer beneficial prophylactic effects. In addition, MSC infusion did not increase the risk of primary disease relapse and infection (RR 1.02, 95% CI 0.70 to 1.50, P = 0.913; RR 0.89, 95% CI 0.44 to 1.81, P = 0.752; respectively). Moreover, there was an apparent trend toward increased overall survival (OS) in the MSC group compared with that in the control group (RR 1.13, 95% CI 0.98 to 1.29, P = 0.084). In conclusion, this meta-analysis demonstrated that MSC infusion is an effective and safe prophylactic strategy for cGVHD in patients with hematological malignancies undergoing allo-HSCT.