C.M. Sublette1, B. Stocker1, B. Ramser1, H. Baig1, C. Erickson1, I. LaCroix1, L. Gallagher1, O. Thielin1, W. Hallas1, S. Sen1, F. Iheagwam1, J. Cardenas1, C. Silliman1, A. D’Alessandro1, K. Hansen1, M. Cohen1 1University Of Colorado Denver, Surgery, Aurora, CO, USA
Introduction: Given the systemic injury of blunt trauma versus localized injury of penetrating trauma, there are assumed inherent differences between the physiologic response to trauma between these two populations, but there is a paucity of research into pathophysiological differences at a molecular level. We hypothesized that there are differences in the proteomic and metabolomic signatures between these groups that are present on admission that may contribute to physiologic trajectories and outcomes.
Methods: Patients meeting the highest level of trauma activation criteria at a Level 1 Trauma Center were prospectively enrolled in this observational study. Plasma samples were collected either in the field or upon arrival to the emergency department prior to the transfusion of blood products. Severe trauma was defined as admission base deficit ≤5 mmol/L and ISS ≥ 15. Proteomic and metabolomic analyses were performed using liquid chromatography-mass spectrometry. MetaboAnalyst was used for statistical analyses of omics data using univariate non-parametric comparisons. Analysis of clinical data was done with non-parametric Fisher Exact Test and Wilcoxon Rank Sum Test as appropriate. P-value ≤ 0.05 defined significance.
Results: Two hundred ninety-two patients with omics data were included in this study. One hundred fifty-nine (54%) had blunt trauma. Ninety patients (31%) had severe trauma, of which 65 (72%) were blunt. All patients with blunt trauma had higher ISS compared to penetrating (17 vs 9, p<.001), but in subgroup analysis of severely injured patients, there was no difference between groups (27 vs, 25, P=0.36). Patients with blunt trauma had higher levels of mannose binding lectin 2 (MBL2) as well as thrombospondin 1 (TSP-1). In the subgroup analysis of patients with severe trauma, fatty acid binding protein 4 and 5 (FABP4 and FABP5) were also higher in blunt trauma patients, and ICAM-2 was lower.
Conclusion: In all trauma patients, those with blunt mechanisms had higher MBL2 and TSP1 levels, both of which are proteins involved in the acute inflammatory response. In patients with severe trauma, blunt trauma patients had lower levels of ICAM2, a protein involved in neutrophil extravasation, as well as FABP4 and 5. FABP 4 and 5 are involved in regulation of fatty acid metabolism as well as having signaling functions associated with development of cardiovascular disease. They are also biomarkers of lipolysis. These findings demonstrate differences between blunt and penetrating trauma patients in multiple pro and anti-inflammatory pathways, as well as metabolic pathways that can affect short and long term outcomes.