A Comparative Study of Different Stem Cell Transplantation for Spinal Cord Injury: A Systematic Review and Network Meta-Analysis

OBJECTIVE: In the present study, we evaluated the efficacy and safety of different stem cell types for spinal cord injury (SCI) therapy to determine the superior treatment of SCI. METHODS: A systematic literature search was performed using PubMed, Embase, the Cochrane Library, Web of Science, VIP, Chinese National Knowledge Infrastructure, and Wan Fang databases from initiation to January 30, 2021. A Bayesian network meta-analysis was performed using ADDIS (Aggregate Data Drug Information System) software. The PROSPERO registration number was CRD42020129635. RESULTS: We included 12 studies with 642 patients in the present study. A network meta-analysis revealed that bone mesenchymal stem cells (BMSCs) combined with rehabilitation training were significantly more effective than rehabilitation training alone in improving the American Spinal Injury Association (ASIA) impairment scale grade (odds ratio, 94.25; 95% confidence interval [CI], 6.71-9321.95), ASIA motor score (weighted mean difference [WMD], 6.67; 95% CI, 0.83-12.73), ASIA sensory functional score (WMD, 12.41; 95% CI, 3.42-21.72), and Barthel index (WMD, 7.24; 95% CI, 0.21-14.30). However, no statistically significant differences were observed between bone marrow mononuclear cells (MNCs) combined with rehabilitation training, umbilical cord-derived mesenchymal stem cells (UCMSCs) combined with rehabilitation training, or UCMSCs alone and rehabilitation alone for all indicators. In terms of safety, there were no serious and permanent adverse effects after transplantation of BMSCs, MNCs, or UCMSCs. CONCLUSIONS: BMSCs plus rehabilitation might be superior to other stem cell treatments of SCI in improving the ASIA impairment scale grade, ASIA motor score, ASIA sensory functional score, and Barthel index. The therapeutic effects of UCMSCs and MNCs remain to be confirmed.