Gene Expression Alterations in Peripheral Blood Following Sport-Related Concussion in a Prospective Cohort of Collegiate Athletes: A Concussion Assessment, Research and Education (CARE) Consortium Study.

BACKGROUND: Molecular-based approaches to understanding concussion pathophysiology provide complex biological information that can advance concussion research and identify potential diagnostic and/or prognostic biomarkers of injury. OBJECTIVE: The aim of this study was to identify gene expression changes in peripheral blood that are initiated following concussion and are relevant to concussion response and recovery. METHODS: We analyzed whole blood transcriptomes in a large cohort of concussed and control collegiate athletes who were participating in the multicenter prospective cohort Concussion Assessment, Research, and Education (CARE) Consortium study. Blood samples were collected from collegiate athletes at preseason (baseline), within 6 h of concussion injury, and at four additional prescribed time points spanning 24 h to 6 months post-injury. RNA sequencing was performed on samples from 230 concussed, 130 contact control, and 102 non-contact control athletes. Differential gene expression and deconvolution analysis were performed at each time point relative to baseline. RESULTS: Cytokine and immune response signaling pathways were activated immediately after concussion, but at later time points these pathways appeared to be suppressed relative to the contact control group. We also found that the proportion of neutrophils increased and natural killer cells decreased in the blood following concussion. CONCLUSIONS: Transcriptome signatures in the blood reflect the known pathophysiology of concussion and may be useful for defining the immediate biological response and the time course for recovery. In addition, the identified immune response pathways and changes in immune cell type proportions following a concussion may inform future treatment strategies.

Similar Concussion Rates in Spring Football and Preseason: Findings From the Concussion Assessment, Research and Education Consortium.

CONTEXT: Increasing attention has been directed toward identifying aspects of football participation for targeted policy change that reduces the concussion risk. Prior researchers evaluated concussion risks during the preseason and regular seasons, leaving the spring season largely unexplored. DESIGN: In this nationally representative observational investigation of 19 National Collegiate Athletic Association Division I collegiate football programs, we assessed concussion rates and head impact exposures during the preseason, regular season, and spring practices from 2014 to 2019. All participating programs recorded the incidence of concussions, and a subset (n = 6) also measured head impact exposures. RESULTS: Analyses by time of year and session type indicated that concussion rates and head impact exposures during all practice sessions and contact practices were higher in the spring and preseason than those in the regular season (P < .05). Concussion rates during the spring season and preseason were statistically similar. CONCLUSIONS: We identified comparable concussion risks in the spring season and preseason, highlighting the need for targeted policy interventions to protect athlete health and safety.