Efficacy of Oligodendrocyte Progenitor Cell Transplantation in Rat Models with Traumatic Thoracic Spinal Cord Injury: A Systematic Review and Meta-Analysis

Spinal cord injury (SCI) is a devastating disease that results in severe motor, sensory, and autonomic dysfunction, for which there are currently no available treatments. Subsequent to the primary mechanical damage, progressive secondary damage further exacerbates the functional deficit. Demyelination may play an important role in the pathogenesis of SCI. Oligodendrocyte progenitor cells (OPCs) are considered a candidate cellular treatment approach for SCI attributable to their unique potential. Here, we conducted a systematic review and meta-analysis to assess the efficacy of OPC transplantation in rat models with traumatic thoracic SCI, and 17 studies (20 experiments, 402 rats) were identified. The Basso, Beattie, Bresnahan (BBB) locomotor rating score, latency and amplitude of motor evoked potential (MEP), percentage of myelinated axons, and cavity size were used as outcome measurements. The pooled results of the meta-analysis in different subgroups (based on cell dose or sex) both suggested that the BBB score of the OPC group was significantly improved compared to that of the control group 2, 4, and 8 weeks after transplantation. Whereas the amplitude of MEP was not significantly different, the latency of MEP was significantly shorter compared to that of the control group 4 weeks after transplantation. The percentage of myelinated axons increased significantly in the OPC group compared to that of the control group after OPC transplantation. Area measurements across groups revealed a significant reduction in cavity size in the OPC-treated groups compared to the control group. In conclusion, OPC transplantation provided considerable beneficial effects after traumatic SCI.