Serum and Cerebrospinal Fluid Levels of S-100β Is A Biomarker for Spinal Cord Injury; a Systematic Review and Meta-Analysis.

introductionThere is controversy regarding the value of serum or cerebrospinal fluid (CSF) levels of S100 calcium-binding protein B (S-100B) in spinal cord injury (SCI). For reaching a general conclusion, the present meta-analysis was designed aiming to evaluate the value of serum and CSF levels of S-100B protein in detecting the presence of SCI in animal studies.

methodsAn extensive search was performed in Medline, Embase, Scopus and Web of science databases. Screening articles, summarizing them and entering data to checklist and quality assessment of the mentioned articles were done by 2 independent reviewers. Data were analyzed and a pooled standardized mean difference (SMD) and 95% confidence interval (95% CI) were presented.

resultsFinally, the data of 7 articles were included in the meta-analysis. Serum level of S-100B had increased as a result of SCI. During the first 6 hours after injury, the level of this protein was very high (SMD=3.8; 95% CI: 2.6 to 5.1; p<0.0001), but as time passed the serum level of the protein had decreased (SMD=0.4; 95% CI: -1.2 to 2.0; p=0.65). In addition, CSF level of the mentioned protein was very high during the initial 6 hours after injury (SMD: 5.8; 95% CI: 3.6 to 8.0), and this elevated level was still observed until 12 hours after injury (SMD: 6.5; 95% CI: 3.7 to 9.3; p<0.0001).

conclusionThe results of the present systematic review and meta-analysis show that measuring the level of S-100Β protein in serum and CSF has a potential value in diagnosis of SCI in animal models. This biomarker increases during the initial 6 hours following injury and remains high until 24 hours after that. However, more than 24 hours after the injury, serum level of this protein returns to the level of animals without SCI.