The efficacy of Schwann cell transplantation on motor function recovery after spinal cord injuries in animal models: A systematic review and meta-analysis

Abstract

Aim: This article aimed to assess the efficacy of Schwann cell transplantation on motor function recovery in animal model of spinal cord injuries via meta-analysis. Methods: An extended search was carried out in the electronic databases of Medline (via PubMed), EMBASE (via OvidSP), CENTRAL, SCOPUS, Web of Science (BIOSIS), and ProQuest. Finally, 41 eligible studies conducted on 1046 animals including 517 control animals and 529 transplanted animals were included in the meta-analysis. Pooled standardized mean difference (SMD) and odds ratio (OR) with 95% confidence interval (95% CI) were reported. Results: The findings showed that treatment with Schwann cells leads to a modest motor function recovery after spinal cord injury (SMD = 0.85; 95% CI: 0.63–1.07; p < 0.001). Transplantation of these cells in acute phase of the injury (immediately after the injury) (OR = 4.30; 95% CI: 1.53–12.05; p = 0.007), application of mesenchymal/skin-derived precursors (OR = 2.34; 95% CI: 1.28–4.29; p = 0.008), and cells with human sources are associated with an increase in efficacy of Schwann cells (OR = 10.96; 95% CI: 1.49–80.77; p = 0.02). Finally, it seems thatthe efficacy of Schwann cells in mice is significantly lower than rats (OR = 0.03; 95% CI: 0.003–0.41; p = 0.009). Conclusion: Transplantation of Schwann cells can moderately improve motor function recovery. It seems that inter-species differences might exist regarding the efficacy of this cells. Therefore, this should be taken into account when using Schwann cells in clinical trials regarding spinal cord injuries