# Association of acute blood biomarkers with diffusion tensor imaging and outcome in patients with traumatic brain injury presenting with GCS of 13–15

## TL;DR

This study found that certain blood biomarkers in mild traumatic brain injury patients correlate with later brain imaging changes and recovery outcomes.

## Contribution

The study links acute blood biomarkers with long-term white matter integrity and recovery outcomes in mild TBI patients.

## Key findings

- Reduced white matter integrity correlates with biomarkers in patients with incomplete recovery.
- Fractional anisotropy is associated with interleukin 10 and tau in incomplete recovery cases.
- Mean and radial diffusivity relate to IL-10, tau, and glial fibrillary acidic protein.

## Abstract

•92 mild TBI patients with biomarkers at admission and DTI ≥ 90 days post-injury.•Reduced white matter integrity associates with biomarkers in incomplete recovery.•Fractional anisotropy associates with interleukin 10 (IL-10) and tau.•Mean and radial diffusivity relate to IL-10, tau and glial fibrillary acidic protein.•Similar but non-significant trends were observed in the full and CT-positive cohorts.

92 mild TBI patients with biomarkers at admission and DTI ≥ 90 days post-injury.

Reduced white matter integrity associates with biomarkers in incomplete recovery.

Fractional anisotropy associates with interleukin 10 (IL-10) and tau.

Mean and radial diffusivity relate to IL-10, tau and glial fibrillary acidic protein.

Similar but non-significant trends were observed in the full and CT-positive cohorts.

The aim of the study was to assess the association between blood-based biomarkers of different cellular origins and later white matter integrity, measured using post-acute diffusion tensor metrics, and their relation to outcome in patients presenting with Glasgow Coma Scale of 13–15 after traumatic brain injury (TBI).

Admission plasma samples for glial fibrillary acidic protein (GFAP), interleukin 10 (IL-10), heart fatty-acid binding protein (H-FABP), S100 calcium-binding protein B (S100B), total tau (T-tau), and amyloid beta 40 and 42 (Aβ40 and Aβ42) were taken for 92 patients. Diffusion-weighted magnetic resonance imaging (DW-MRI) and outcome evaluation was done ≥ 90 days post-injury. Outcome was assessed using Glasgow Outcome Scale-Extended (GOSE) and dichotomized as complete (GOSE 8) and incomplete (GOSE < 8) recovery. Mean fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were calculated from the skeletonized white matter tracts of the whole brain.

IL-10 and T-tau showed significant weak-moderate negative correlations with FA, and significant positive correlations with MD and RD in incompletely recovered patients. GFAP showed significant weak positive correlations with MD and RD, while its correlation with FA was slightly below significance threshold after correction for multiple comparison in incompletely recovered patients. Similar trends were observed in the whole cohort and in the CT-positive cohort, although these did not reach statistical significance.

Higher acute levels of GFAP, IL-10 and T-tau may be associated with the development of axonal injury. If validated in future studies, these biomarkers may help identify patients who require closer follow-up and DW-MRI.