Acute inflammation in traumatic brain injury and polytrauma patients using network analysis

INTRODUCTION: traumatic brain injury (TBI) is associated with secondary injury to the central nervous system (CNS) via inflammatory mechanisms. The combination of polytrauma and TBI (TBI) further exacerbates the inflammatory response to injury, however combined injury phenomena has not been thoroughly studied. In this study, we examined the inflammatory differences between patients with TBI versus patients with polytrauma but no TBI (polytrauma). We hypothesize that patients with TBI have a heightened early inflammatory response compared to polytrauma. METHODS: We conducted a single center retrospective study of a cohort of patients with polytrauma who were enrolled in the PROPPR study. These patients had blood samples prospectively collected at eight time points in the first 3 days of admission. Using radiological data to determine TBI, our polytrauma cohort was dichotomized into TBI (n=30) or polytrauma (n=54). Inflammatory biomarkers were measured using ELISA. Data across time were compared for TBI vs. polytrauma groups using Wilcoxon rank sum test. Network analysis techniques were used to systematically characterize the inflammatory responses at admission. RESULTS: Patients with TBI (51.6%) had a higher 30-day mortality compared to polytrauma (16.9%) (p-value