TBI Outcome-associated Biomarkers in Patients of African Ancestry or African American Race: A Review of the Literature

Introduction: Traumatic brain injury (TBI) is a major global cause of death and disability. In the USA, TBI patients who racially identify as black or African-American have been shown to have higher mortality and worse functional outcomes than patients who identify as white. Advancing health equity in TBI requires prioritizing translational research in underserved populations such as racial and ethnic minorities that have been historically excluded from major biomedical research agendas. Assessing inclusion of these populations in research on TBI biomarkers can help characterize the gap in TBI research equity. We therefore performed a review of the current literature on TBI biomarkers in individuals who racially identify as black, and/or are of African ancestry.

Methods: We conducted a PubMed literature search of studies analyzing genomic, transcriptomic, or proteomic biomarkers associated with TBI outcome. Inclusion criteria were human studies assessing TBI biomarker levels by race, ethnicity, or ancestry demographics. Studies that did not include participants of African ancestry, or participants racially identifying as black or African American, were excluded.

Results: Initial search returned 1,408 citations, which were further screened for eligibility and the inclusion/exclusion criteria. Black and African-American participants were largely underrepresented in the eligible citations. Select studies specifically focused on TBI biomarkers in black-identifying individuals. Variation in levels of established biomarkers, including S100B, UCH-L1, Aß-42, and tau, varied in Black participants, compared to white participants at physiological baseline as well as after TBI accident.

Conclusion : Further work is still required to investigate biomarkers associated with TBI outcome in individuals who identify as black or those of African ancestry. Current literature suggests variation in biomarker levels may exist, positing the importance of additional investigation of TBI outcome biomarkers in individuals who are historically excluded from neuroscience research, such as people of African ancestry.