Correlation of serum cystatin C with inflammatory cytokines in patients with traumatic brain injury.

Traumatic brain injury (TBI) is a world-wide leading health problem with high morbidity and mortality rates. Emerging studies have demonstrated that TBI is the consequence of a series of inflammatory responses in the body. The alteration of Cystatin C (Cys C) was reported in a variety of chronic inflammatory diseases and was also recommended as a biomarker for predicting renal diseases. In this study, we aimed to investigate the relationship between serum Cys C and TBI, and to evaluate the prognostic role of Cys C in TBI prediction. One hundred and seventy-six patients with TBI were recruited and 102 patients were finally analyzed, with 30 healthy control subjects. The concentrations of Cys C were significantly reduced in the healthy control group compared to the TBI group, and correlated with high GCS scores. The levels of hsCRP, counts of white blood cells, and levels of IL-6 and TNF-α were remarkably elevated in the TBI patients compared with the control group in a severity-dependent manner. Moreover, the concentration of Cys C was negatively correlated with TBI severity and positively correlated with inflammatory factors. In conclusion, serum Cys is an inflammatory cytokine-related factor and might indicate the severity of TBI thus serving as a prognostic biomarker.