Efficacy and safety of autologous hematopoietic stem cell therapy for refractory Crohn's disease: A systematic review and meta-analysis

Background:Autologous hematopoietic stem cell transplantation (HSCT) has been proposed for patients with refractory Crohn's disease (CD), but it is associated with mortality and adverse events; the balance between risks and benefits becomes significantly important in the therapy. The aim of the study was to assess the efficacy and safety of autologous HSCT therapy for refractory CD.Methods:We conducted a comprehensive search of PubMed, Embase, the Cochrane library, and Web of Science from inception to February 2017. The pooled estimate rates for efficacy and safety of refractory CD was performed by meta-analysis and reported according to the standard Cochrane guidelines and the PRISMA statement.Results:Four prospective uncontrolled cohort studies, 4 prospective case series, and 1 randomized controlled trial (RCT) were included. Autologous HSCT had a high rate of clinical and endoscopic remission in refractory CD [79.4%, 95% confidence interval (95% CI): 0.550-0.924; 81.9%, 95% CI: 0.603-0.931, respectively]. In the case of safety, it had a relatively high incidence rate of transplant-related mortality (6.4%, 95% CI: 0.028-0.140). A significant association was observed between autologous HSCT and the incidence of febrile neutropenia (83.2%, 95% CI: 0.632-0.934). About 18.5% (95% CI: 0.061-0.442) of patients with refractory CD reached clinical remission at mobilization phase. Besides, 82.1% (95% CI: 0.692-0.903) and 54.1% (95% CI: 0.261-0.797) patients with refractory CD could achieve immunosuppressive-free and steroid-free remission for at least 12 months after the therapy.Conclusion:Autologous HSCT could be a complicated treatment with relatively high mortality and significantly high efficacy for refractory CD, which should be used with caution. However, more RCTs of larger samples using refined and standardized protocols and longer period of follow-up time are needed to further assess the outcomes of autologous HSCT therapy.