Blood-based Biomarkers for the Prognosis of Sports Related Concussion
Condition: Traumatic Brain Injury; Sports Injury; Concussion, Mild
MeSH terms: Brain Injuries; Brain Injuries, Traumatic; Brain Concussion; Wounds and Injuries; Athletic Injuries
Study type: Observational

Summary: 
      The diagnosis of sports related concussion still relies heavily on a subjective assessment.
      In this study the investigators want to assess the prognostic value of blood-based biomarkers
      with recovery from concussive episodes over specific time points post-injury. Our research
      aims to (1) assess that the World Rugby's head injury assessment (HIA) can identify that a
      concussion has taken place by measuring specific biomarkers in the blood and (2) to track
      these biomarkers over time post-injury as a means to assess player health.
    

Detailed description: 
      The diagnosis and prognosis of sports related concussion (SRC) still rely on a subjective
      assessment based on the SCAT5 procedure. Our knowledge of how sports related concussion
      effects an athlete over time is limited as all patients may have different recovery times
      from concussion. Our research aims to quantitatively confirm that the head injury assessment
      has predicted a concussion against clinical assessment (SCAT5) and that a return to play
      protocol allows sufficient recovery time for an athlete.

      Numerous novel areas of diagnosis are currently under investigation including protein-based
      biomarkers. In the context of SRC, these protein biomarkers typically consist of neurological
      proteins normally confined to the central nervous system or associated with neurological cell
      damage. Recent studies have compared biomarker levels at different time points post-diagnosis
      or investigated the relationship between early biomarker levels and return to play (RTP)
      times. However, the use of these biomarkers for actively evaluating player recovery following
      SRC has yet to be fully investigated. In this study, the investigators will measure
      biomarkers levels across multiple time points post-SRC to assess the value of these
      biomarkers to monitor player recovery. This is of significant for minimising premature RTP
      and, ultimately, aiming to reduce the chronic long-term effects associated with SRC.

      To truly identify a biomarker specific to concussion this study will need to, first, analyse
      the bloods of concussion patients and compare to the clinical assessment of the head injury
      assessment (HIA), and, second, measure their levels over time to indicate recovery that may
      aid in a safe return to play.

      Briefly, blood samples are taken from consented participants at the start of pre-season to
      act as a baseline. Once one of these participants enters the HIA process their bloods are
      taken post-injury, 6 days after injury and 13 days after injury. Next, the biomarkers are
      measured in the blood samples at each time point to examine if there is any increase/decrease
      in their levels.

      Study Design:

      A prospective cohort study with an uninjured and exercise free control groups.

      Population:

      All participants are professional rugby players from one professional rugby club were
      initially invited to participate. Initial contact was made to the Irish Rugby Football Union
      (IRFU) chief medical officer for permission to run the study over a three-year period. Next
      permission to run this cohort study was sought from the head coach and medical staff of the
      professional rugby team.

      Baseline Questionnaire:

      Participants will complete a baseline questionnaire that includes questions regarding their
      concussion history including symptoms associated with, length of, and outcome of previous
      injuries. The questionnaire was developed in line with previous sports-based concussion
      studies used for ice hockey and Australian football

      Timeframes

      As part of this study, any participant that enters the standard HIA process will undergo a
      HIA, a neuropsychometric assessment, and blood sampling at the following time points:

        1. Within 72 hours of injury,

        2. 6 days post-injury (± 1 day); this aligns with the minimum graduated return to play
           (GRTP) protocol for a professional rugby player, no player will return to play before 6
           days,

        3. 13 days post-injury (± 1 day) to examine if biomarkers are still present despite the
           results the HIA and the neuropsychometric assessment.

      Serial HIA Participants that suffer a suspected SRC will complete the HIA protocol at the
      time points outlined above. This is a form of the SCAT5 which has been modified for
      professional rugby and GRTP. This assessment will be carried out by the medical officer of
      the professional rugby club.

      Neuropsychometric Assessment During preseason players complete a baseline computed based
      neuropsychometric assessment - ImPACT. This assessment measures different cognitive domains
      including visual memory, visual processing speed, reaction times and working memory as well
      as attention. Post injury players are re-assessed once symptom free to determine recovery fo
      these domains and to assess for any persistent patterns of deficit. This assessment forms a
      part of the overall concussion assessment and management plan.

      Blood Draw:

      The medical officer and/or clinical nurse will take the samples of blood at the timepoints
      outlined above. The medical officer or nurse usually takes the blood sample from the
      antecubital vein in the arm.

      Bloods are collected by a member of the study team from the medical officer or nurse after
      the participant has left to ensure confidentiality. Three types of sample vials are used to
      ensure different types of biochemical techniques can be used and certain markers can be
      examined; serum, plasma and whole blood. Whole blood samples are immediately aliquoted in 2
      mL cryo-vials of 1- 1.5 mL each. For serum samples the blood is allowed to clot within the
      tube for up to 30 minutes. For both serum and plasma vials, they are centrifuged at 2,000 xg
      for 10 minutes at 4 °C. The serum and plasma are carefully pipetted and aliquoted into
      respective 2 mL cryo-vials with no less than 400 µL in each cryo-vial. All aliquoted
      cryo-vials are placed into storage boxes within a -80 °C freezer for long-term storage. Each
      aliquot can be removed to probe for different biomarkers without multiple freeze-thaw cycles
      on the core sample.

      Blood Biomarkers The blood-based biomarkers that can be analysed using standard biochemical
      techniques for a targeted and hypothesis-based procedures using ELISA kits or Luminex
      multiplex assays. Serum and plasma samples allows for a multitude of targets to be analysed
      which may be found in either serum or plasma. For this type of analysis common targets can be
      used to compare across the timepoints. The biomarkers under investigation can be but not
      limited to s100β, ubiquitin carboxyl-terminal hydrolase isoenzyme L1, glial fibrillar acidic
      protein and total, Tau protein and Brain-derived neurotrophic factor.

      Outcomes Each participant that is believed to have a SRC will enter the HIA process. These
      participants will have clinical assessments conducted at pre-defined time points, in line
      with the World Rugby guidelines. Blood samples will also be acquired at these time points to
      quantify the levels of blood-based biomarkers. Biomarker levels will be correlated to the
      results of the HIA and neuropsychometric assessments. This will facilitate preliminary
      investigation of the correlation between clinical assessments and biomarker levels to
      determine if the biomarkers can be used to objectively assess SRC recovery

      Investigations:

      A collaborative relationship exists between this research group and the University of
      Limericks (UL) Clinical Research Support Unit (CRSU). The CRSU provided advice and supported
      the delivery of this research project to the highest standard of research and clinical
      governance in accordance with the requirements of ICH Good Clinical Practice (ICH-GCP)
      Guidelines and all applicable regulatory requirements. The participant contact element of
      this study was conducted by adhering to the CRSU's Quality Management System (QMS).
    

Intervention name(s): Biochemical Analysis of Blood Biomarkers
Intervention type(s): Diagnostic Test
Intervention description(s): Using established biochemical techniques, the bloods will be probed for specific biomarkers s100B, UCH-L1, GFAP, and BDNF. The techniques include individual ELISA kits for each biomarker mentioned and Luminex multiplate assay which will probe for all biomarkers in one plate. Ultimately, these techniques will be able to measure the level of these biomarkers in the blood relative to the participants baseline reading.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        All participants are professional rugby players from a professional rugby club were have
        been invited to participate. Initial contact was made to the Irish Rugby Football Union
        (IRFU) chief medical officer for permission to run the study over a three-year period. Next
        permission to run this cohort study was sought from the head coach and medical staff of the
        professional rugby team.
      
Biospecimen description: 
      Blood samples at each time point are taken. Approximately, 30 mL of blood are drawn across 3
      vials to allow for collection of whole blood, serum and plasma from the same participant at
      each time point.
    
Keywords: blood-based biomarker; prognosis; SCAT5; head injury assessment; return to play protocol; sports related concussion