Relationship between YKL-40, neuron-specific enolase, tumor necrosis factor-α, interleukin-6, and clinical assessment scores in traumatic brain injury

Background and Objectives: The aim of the present study is to determine plasma and cerebrospinal levels of YKL-40, in combination with neuron-specific enolase (NSE), interleukin (IL)-6, tumor necrosis factor (TNF)-alpha, and the clinical scales such as Glasgow Coma Scale, Acute Physiology and Chronic Health Evaluation a III, and MARSHALL classification in traumatic brain injury (TBI). Materials and Methods: This was a prospective study conducted on patient cohort of 27 patients with isolated severe TBI. Cerebrospinal fluid (CSF) and plasma were collected on the 24th and 96th h after trauma. CSF samples were obtained also from forensic autopsies of 29 adult healthy cadavers. Results: The CSF level of YKL-40 in TBI patients was higher compared to controls, while no significant change between CSF NSE levels in patients and controls was found. We determined a strong correlation between YKL-40 and NSE levels and TBI clinical assessment scores. The analysis of the influence of independent prognostic factors on the outcome of TBI patients showed that plasma NSE concentrations are the major independent variable which is associated with the survival of TBI patients. Still, changes in IL-6 and TNF-alpha levels could not be considered as reliable predictors of mortality. Conclusion: We present data for correlation of YKL-40 and NSE levels with clinical scores for assessment of trauma severity and the outcome of TBI patients. Even though further large-scale investigations are required to clarify and evaluate the clinical significance of both biomarkers, our findings suggest that YKL-40 and NSE might be implicated in the pathogenesis of TBI and could indicate the degree of neuroinflammation and brain damage.