Neuroinflammatory Biomarkers and Their Associations With Cognitive, Affective, and Functional Outcomes 3 to 12 Months After a Traumatic Brain Injury: A Pilot Study.

Background: Neuroinflammation is an important feature of traumatic brain injury (TBI) that remains poorly understood in the 3- to 12-month period post-TBI.

Objective: The purpose of our pilot study was to examine the relationships between biomarkers of neuroinflammation and functional outcomes in TBI patients 3 to 12 months postinjury.

Methods: TBI patients (n = 36) 3 to 12 months post-TBI were recruited from a South Florida TBI clinic from May 2022 to June 2023. The Disability Rating Scale, Satisfaction with Life Scale, NIH Toolbox Sorting Working Memory, Neuro-Quality of Life Cognitive Function, Anxiety, Depression, and Sleep assessments were performed. Multiple plasma biomarkers were assayed. Analysis of variance was used to compare between-group results. Linear regression was performed to analyze relationships between biomarkers and outcomes.

Results: Brain-derived neurotrophic factor concentrations were higher as postinjury time interval increased and were associated with cognitive battery outcomes. S-100β and glial fibrillary acidic protein were associated with anxiety score and hospital length of stay; S-100β was also associated with depression. Interleukin 6 was associated with cognitive function score and time since injury.

Conclusions: We found S-100β, glial fibrillary acidic protein, Interleukin 6, and brain-derived neurotrophic factor to play a larger role in the TBI recovery period than other biomarkers examined. Clinicians should continue to monitor for symptoms post-TBI, as the neuroinflammatory process continues to persist even into the later rehabilitation stage.