Identifying a Biological Signature of Trauma-Related Neurodegeneration Following Repeated Traumatic Brain Injuries Compared with Healthy Controls

Topic/Product:
CNS Disease Panel 120, Neurology
Disease Area:
Traumatic Brain Injury (TBI)
Sample Type:
Plasma

Abstract

The objective of this study was to compare participants at-risk for trauma-related neurodegeneration to a healthy control group on outcomes associated with Alzheimer’s disease (AD), such as subjective symptoms, neurocognitive performance, plasma biomarkers, volumetrics, amyloid-beta (Aβ) positron emission tomography (PET), and tau PET. Participants completed a comprehensive assessment protocol for neurodegenerative disease, including magnetic resonance imaging (MRI), PET scans for tau and Aβ, blood draw, subjective symptom reports related to neurodegenerative disease, and objective neurocognitive assessment. Surveys included the Neurobehavioral Symptom Inventory (NSI), Insomnia Severity Index (ISI), Epworth Sleepiness Severity (ESS), PTSD Checklist for DSM-5 (PCL-5), Brief Symptom Inventory-18 (BSI-18), Satisfaction with Life Scale (SWLS), Barratt Impulsivity Scale (BIS), and Buss Perry Aggression Questionnaire (BPAQ). PET scans were read by a neuroradiologist and rated positive or negative based upon established cutoffs. General linear models compared participants with TBI history with controls on outcomes. Age, years of education, military status, biological sex, race/ethnicity, and total self-reported TBIs were included as covariates in all models with Bonferroni corrections. Forward stepwise linear regression models were built to associate neuroimaging outcomes with symptom domains; inclusion in the linear regression required a p value <0.1. The average age for both groups was ∼40 years. The TBI group reported an average of five TBIs; the control group reported an average of one TBI. Across seven regions of interest, only one TBI participant met established PET cutoffs for neuropathology in one cortical region. After controlling for age, sex, race/ethnicity, years of education, military status, and TBI history, there were no statistically significant differences between groups in any neurocognitive outcome (p = 0.06–0.95), Aβ or tau PET (p = 0.05–0.70), MRI volumetrics (p = 0.06–0.98), or plasma biomarkers (p = 0.06–0.85). The TBI group had higher NSI, PCL-5, BSI-18, BPAQ, ESS, and ISI scores compared with the controls (p < 0.001–0.042). Within the TBI group, amygdala normative percentile and/or amygdala asymmetry index were included in the final models for NSI, SWLS, PCL5, BIS, BPAQ, and ISI. Only two models included a statistically significant PET outcome in the final model. In this sample with a mean age of 40 and a history of 5+ TBIs, core diagnostic biomarkers for AD were not different from controls despite significantly higher symptom burden. Volumetrics in critical brain regions were associated with several symptom domains in the TBI group, indicating that cortical volumetrics (especially in the amygdala) may be a more viable early biomarker of chronic symptom burden in this population than PET scans.

Authors & Affiliations

Shawn R. Eagle¹*, Ava Puccio¹, Sarah Svirsky¹, James Mountz², Charles Laymon², Allison Borasso¹, Luke Henry¹, and David O. Okonkwo¹

¹ Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA
² Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA

Steve Williams, MD, PhD

CSO

Dr. Willams serves as the company’s Chief Scientific Officer. He was previously Chief Medical Officer at Standard Biotools and at SomaLogic where he pioneered the discipline for discovery and validation of predictive, diagnostic and prognostic models using machine-learning applied to large-plex proteomics. 20 such tests were used for drug characterization, safety and efficacy when incorporated in clinical drug trials at Pharma/Biotech and 17 different multivariate tests were validated and translated into regulated healthcare uses. Prior to SomaLogic, Dr. Williams was at Pfizer in the UK and the USA as a clinical triallist in Translational Medicine, and subsequently as VP, Global Clinical Technology. He sat on the National Advisory Council for the National Institute of Biomedical Imaging and Bioengineering, the Executive Committee for the FNIH Biomarkers Consortium, and worked with FDA and PhRMA on developing evidentiary standards for biomarker qualification. Dr. William’s medical training was in London, at Charing Cross and Westminster Medical School, followed by a PhD in medicine/physiology at the same institution and training in Radiology at the University of Newcastle Upon Tyne. Steve is co-inventor on 26 proteomics patents and author/coauthor on multiple foundational proteomics manuscripts.

Justin McAnear

CFO

Mr. McAnear serves as the company’s Chief Financial Officer. He brings over 25 years of operational and financial leadership experience across various sectors and was instrumental in taking 10x Genomics public in 2019, serving as its CFO for over five years. Mr. McAnear served for over 3 years as Tesla’s VP of Worldwide Finance and Operations, supporting landmark initiatives such as the Model X and Model 3 launches and Solar City acquisition.  He also held various roles at Apple and J&J earlier in his career and served as a naval officer and aviator for over 9 years.