Active and Passive Immunization with Myelin Basic Pro-tein as a Method for Early Treatment of Traumatic SpinalCord Injury; a Meta-Analysis

Traumatic spinal cord injury (SCI), as a dangerous central nervous system damage, continues tothreaten communities by imposing various disabilities and costs. Early adjustment of the immune system re-sponse using Myelin Basic Protein (MBP) immunization may prevent the SCI-related secondary damages. As aresult, the current study is designed to review and analyse the evidence on active and passive immunization withMBP for treatment of traumatic SCI.

Medline, Embase, Scopus, and Web of Science databases weresystematically searched until the end of 2020. Criteria for inclusion in the current study included pre-clinicalstudies, which performed passive (injection of MBP-activated T cells) or active (administration of MBP or MBP-modified peptides) immunization with MBP after traumatic SCI. Exclusion criteria was defined as lack of a non-treated SCI group, lack of evaluation of locomotion, review studies, and combination therapy. Finally, analyseswere conducted using STATA software, and a standardized mean difference (SMD) with a 95% confidence in-terval (CI) were reported.

Data from 17 papers were included in the present study. Finally, analysisof these data showed that passive immunization (SMD=0.87; 95%CI: 0.19-1.55; p=0.012) and active immuniza-tion (SMD=2.08, 95%CI: 1.42-2.73; p<0.001) for/with MBP both have good efficacy in improving locomotionfollowing traumatic SCI. However, significant heterogeneity was observed in both of them. The most impor-tant sources of heterogeneity in active immunization were differences in SCI models, route of administration,time interval between SCI and transplantation, and type of vaccine used. In passive immunization, however,these sources were the model of SCI and the time interval between SCI and transplantation. Although, there wassubstantial heterogeneity among studies, subgroup analysis showed that active immunization improved loco-motion after traumatic SCI in all tested conditions (with differences in injury model, severity of injury, method ofadministration, different time interval between SCI to vaccination, etc.).

The results of the presentstudy demonstrated that immunization with MBP, especially in its active form, could significantly improve mo-tor function following SCI in rats and mice. Therefore, it could be considered as a potential treatment in acutesettings such as emergency departments. However, the safety of this method is still under debate. Therefore,it is recommended for future research to focus on the investigation of safety of MBP immunization in animalstudies, before conducting human clinical trials.