Systemic inflammation and its associations in acute moderate-severe Traumatic Brain Injury: a cross-sectional study.

Traumatic Brain Injury (TBI) triggers an acute systemic inflammatory response, which may impact outcomes. This response may interact with pre-existing factors linked to inflammation, such as age, to influence outcomes. Previous studies have typically measured few cytokines, but high-dimensional proteomic approaches can sensitively detect a broad range of inflammatory markers, to better characterise post-TBI inflammation. We analysed plasma from BIO-AX-TBI study participants (n = 37 acute moderate-severe TBI (Mayo Criteria), n = 22 acute non-TBI trauma (NTT), n = 28 non-injured controls (CON)) using the Alamar NULISA™ panel (>200 inflammatory markers). The NTT group enabled differentiation of TBI-specific versus general injury-related responses. Inflammatory markers were correlated with plasma NFL, GFAP, total tau, UCH-L1 (Simoa®), S100B (Millipore), and subacute (10 days-6 weeks) 3T MRI measures of lesion volume and white matter injury. Differential expression analysis identified four markers elevated specifically in TBI (VSNL1, IL1RN/IL-1Ra, GFAP, IKBKG), while other derangements reflected non-specific injury responses. Higher VSNL1 correlated with greater lesion volume (r