A prospective study on serum secreted protein acidic and rich in cysteine-like 1 as a prognostic marker for severe traumatic brain injury.

Background: Secreted protein acidic and rich in cysteine-like 1 (SPARCL1) regulates synaptic stability with upregulation throughout axonal regeneration. Our study aims to determine the correlation of serum SPARCL1 concentrations with the severity and in-hospital mortality of severe traumatic brain injury (sTBI).

Methods: A total of 102 consecutively recruited patients admitted for sTBI and 102 randomly selected healthy controls were included in this observational prospective study. Serum SPARCL1 concentrations were measured and correlated with Glasgow coma scale (GCS) scores and in-hospital mortality using multivariate analysis.

Results: Compared with controls (median, 0.22 ng/ml; interquartile range, 0.19-0.41 ng/ml), patients had significantly higher SPARCL1 concentrations (median, 3.29 ng/ml; interquartile range, 1.88-4.37; P < 0.001). There was an independently correlation between SPARCL1 concentrations and GCS scores (t = -7.011, P < 0.001). We found a high area under receiver operating curve (AUC) of serum SPARCL1 concentrations to predict in-hospital mortality (AUC, 0.822; 95% confidence interval, 0.734-0.891). In the multiple logistic regression analysis, serum SPARCL1 concentrations >3.29 ng/ml was independently associated with in-hospital mortality (odds ratio = 10.052, 95% confidence interval = 1.918-52.686, P = 0.006).

Conclusions: The novel findings of our study are that sTBI patients had an increase of serum SPARCL1 concentrations, and that there is an association between high serum SPARCL1 concentrations and sTBI mortality or trauma severity.