Near-care assay of plasma glial fibrillary acid protein and ubiquitin carboxyl- terminal hydrolase isozyme L1: impact of exercise-heat stress

Near-care assay of plasma glial fibrillary acid protein and ubiquitin carboxyl- terminal hydrolase isozyme L1: impact of exercise-heat stress | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Near-care assay of plasma glial fibrillary acid protein and ubiquitin carboxyl- terminal hydrolase isozyme L1: impact of exercise-heat stress Mike Stacey, Amanda Barden, Daniel Snape, Wainwright Barney, Iain Parsons, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7970895/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 10 Feb, 2026 Read the published version in Scientific Reports → Version 1 posted 11 You are reading this latest preprint version Abstract Objectives Neurobiomarkers measured in peripheral blood can supplement management strategies following Traumatic Brain Injury (TBI). Dual-assay of glial fibrillary acid protein (GFAP) and ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1) is FDA-approved for assessing, at near-care, a decision threshold for post-TBI neuroimaging. As physical activity and thermal strain often accompany TBI-prone activities, we investigated whether each molecule’s quantification - and, by extension, clinical decisions - could be influenced by exercise-heat stress. Methods In healthy volunteers monitored continuously for body core temperature (Tc), we used the i-STAT Alinity® to investigate plasma GFAP and UCHL1 responses to exercise in the laboratory (three female, seven male trained participants, cycling for 45 min in 32°C) and field (three female and 22 male recreational marathon runners, finishing time 231 ± 34 min, peak ambient temperature 11°C). Results Respective ΔTc overall were 1.42 ± 0.37°C and 1.87 [1.53, 2.31] °C. With laboratory exercise, GFAP and UCHL1 did not exceed the manufacturer’s decision threshold. Across the marathon, GFAP was also stable, whereas UCH-L1 more than doubled (200 [200, 200] vs 462 [310, 782] µg.L-1, P < 0.0001), breaching the decision threshold for neuroimaging in 18/25 runners. Discussion Confounding from more prolonged exercise-heat stress should be considered when managing TBI using near-care assay of UCHL1. Health sciences/Biomarkers Health sciences/Medical research Health sciences/Neurology Biological sciences/Neuroscience Figures Figure 1 Figure 2 Introduction In distinguishing significant brain lesions consequent upon Traumatic Brain Injury (TBI), quantification of biomarkers indicative of neurological processes (neurobiomarkers) in peripheral blood presents a less hazardous and potentially cheaper alternative to computed tomography (CT).[ 1 ] Glial fibrillary acid protein (GFAP) and ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1) have been approved for dual assay as a rapid near-care tool to exclude more severe TBI. The Alinity iSTAT provides an automated, cartridge-based system, generating semi-quantitative results within 15 minutes and showing close correlation with benchtop analytical platforms.[ 2 ] The wider study in which relationships between cartridge near-care and benchtop laboratory assays were derived categorised only 2.5% of patients as suffering from exercise-associated TBI,[ 3 ] yet recreational and occupational activities account up to 20% of all cases.[ 4 , 5 ] Given the prevalence of TBI in physically demanding and thermally stressful environments, and more recent findings that physical activity may differentially influence each neurobiomarker,[ 7 , 8 ] it is important to establish whether prolonged exercise and heat exposure can independently impact decision thresholds on the Alinity. Thus the aim of this study was to establish whether GFAP and UCHL1 responses would vary between shorter duration exercise performed in the laboratory, and upon more prolonged exercise-heat stress in a field environment. Results Baseline volunteer characteristics are displayed in Table 1 . Table 2 shows physiological responses to each exposure. Table 1 Baseline (pre-exercise/-acclimatisation) volunteer characteristics for laboratory and field studies. n Age (y) Female (%) Height Weight BSA (m 2 ) Laboratory 20 30 ± 7 25.0 177 ± 8 73.3 ± 12.4 1.90 ± 0.18 Field 25 31 ± 5 11.5 178 ± 8 75.4 ± 12.0 1.93 ± 0.18 Table 2 Physiological responses to 45 min Heat Stress Test (Study 1) and marathon participation (Study 2, 231 ± 34 min duration). Study 1 Study 2 P-value Resting Tc 37.08 [36.91, 37.21] 37.29 [36.98, 37.55] 0.0663 Post-exercise Tc 38.42 [38.33, 38.82] 38.66 [38.16, 39.15] 0.4128 Mean Tc 37.83 {37.71, 37.99] 38.18 [37.73, 38.72] 0.0311 Maximum Tc rise 1.31 [1.18, 1.76] 1.87 [1.53, 2.31] 0.0005 Body mass change (kg) -1.25 ± 0.27 -1.3 [-0.35, -2.35] 0.7507 Supplementary Fig. 1. Glial Fibrillary Acid Protein (GFAP) and Ubiquitin Carboxyl-terminal Hydrolase isozyme L1 measured by ELISA (BENCH) in 25 participants who successfully completed the marathon, sampled at rested baseline (B), upon event completion (T0, n = 25) and next-day (T24, n = 7). LLOQ, lower limit of quantification; TBI, Traumatic Brain Injury (decision threshold). In Study 1, CARTRIDGE for both GFAP and UCHL1 remained below LLOQ, with no values challenging respective TBI decision thresholds (30 µg.L − 1 and 360 µg.L − 1 ). BENCH GFAP was unchanged with HST (0.025 [0.025, 0.025] vs 0.025 [0.025, 0.058] pmol.L − 1, P = 0.5156], whereas BENCH UCHL1 (230.3 [19.6, 1062.0] vs 170.6 [19.60, 619.30] pmol.L − 1 , P = 0.0093] decreased modestly. In Study 2, the CARTRIDGE decision threshold for GFAP was breached on one occasion only, in T24 sampling, with all other values remaining < LLOQ and no significant variation overall. For UCHL1, 18/25 runners exceeded the corresponding CARTRIDGE decision threshold upon marathon completion (Fig. 1 ). In BENCH measures, both GFAP and UCHL1 were unchanged with marathon participation (Supplementary Fig. 1). Bland Altman plot of log UCHL1 post -marathon (T0) is shown at Fig. 2 (BENCH vs CARTRIDGE). Bias was 1.39 ± 1.46 (95% limits of agreement − 1.474 to 4.255), with no significant correlation between methods (P = 0.1834). Discussion Across two studies of shorter and longer duration exercise, we have demonstrated differential responses in neurobiomarkers quantified by near-care testing. While CARTRIDGE measures of GFAP and UCHL1 remained below LLOQ with a shorter cycle ergometry protocol in the heat, significant variation was observed for UCHL1 with longer duration running, sufficient to breach the TBI cut-off value in a majority of participants. In the first 24 h following TBI, elevated plasma UCHL1 associated with worse functional outcomes and poorer quality of life.[ 9 ] However even in the absence of TBI, delayed UCHL1 rise has been reported post-exercise, with UCHL1 increasing in proportion to the duration of the bout (aerobic/anaerobic conditioning over 40 to 196 minutes),[ 7 ] and progressively throughout recovery (immediately post-3 h submaximal cvcling, and again at 2 and 24 h).[ 8 ] Both protocols employed a benchtop ELISA rather than the iSTAT, nevertheless apparent failure of UCHL1 values to challenge decision threshold associated with the latter provided relative reassurance to clinical application in the context of prior exercise. However in the present work sampling close to marathon completion revealed greater elevation, with median CARTRIDGE UCHL1 of 462 mcg.L − 1 substantially exceeding the iSTAT decision threshold of 360 mcg.L − 1 . Factors that may have favoured relative increase in UCHL1 in Study 2 versus Study 1 and previous work may include the longer time window available for release of UCHL1 from neurons and extracranial sources, such as gonadal tissues;[ 10 ] greater CNS insult from torsional forces increased with running versus static laboratory cycling; relative increase in blood brain barrier (BBB) permeability to enhance UCHL1 entry into the peripheral circulation, with progressive BBB opening observed under exercise at higher core body temperature and with dehydration;[ 11 ] and impaired UCHL1 clearance by the liver and spleen, due to reduced blood flow with exercise and thermoregulation. Alternatively, it is conceivable that the increase in CARTRIDGE UCHL1 with marathon participation was artefactual and perhaps related to interfering substances appearing relative to settings of increased physical stress, or to freeze/thawing. However, we deem this less likely, because (1) many of the TBI cases recruited to the validation work for the UCHL1 CARTRIDGE assay suffered TBI in the setting of polytrauma, with multiple other body tissues affected and associated physiological strain from haemorrhage (2) in the FDA approval process, no elevation in UCHL1 was observed from assay cross-talk with any other tested substance, including caffeine, acetaminophen and non-steroidal anti-inflammatory agents (i.e. common ergogenic aids used by athletes)[ 12 ] and (3) analysis was achieved within the post-collection time window recommended by the manufacturer, and the stability of frozen plasma specimens relative to fresh was established as part of the FDA submission process.[ 13 ] Considering other potential limitations of our work, we acknowledge under-representation of female participants in the study, relative to the general population, though males are more commonly head-injured, with a sex ratio between 2.0:1 and 2.8:1 likely reflecting greater participation of men in high-risk activities that lead to TBIs, including those involving exercise and thermal stress. It does appear that UCHL1 in peripheral blood is slightly higher in males than females, both in TBI and in health,[ 14 ] therefore women may not show such a bias as men when the Alinity iSTAT is used soon after physical activity. The age of our study cohorts was also relatively young (study 1: 30 ± 7 years ; study 2, 31 ± 5 years, Table 1 ), though again approximately one-half of all patients with mild TBI are between the ages of 15 and 34 years,[ 4 ] and these are exactly the patients who would benefit most from avoiding ionising radiation (compared with older individuals suffering trips and mechanical falls, who have less concern for lifetime irradiation effects). The timespan within which diagnostics inform clinical pathways is becoming compressed by advancements in available technologies, including the recent market release of whole blood assay for GFAP/UCHL1 on the iSTAT Alinity. We conclude that caution should be exercised in the clinical interpretation of near- or point-of-care assays where prolonged prior exercise-heat stress may exist, and that further research is needed in this area. Methods Standard Protocol Approvals, Registrations, and Patient Consents Individual institutional approvals were granted separately to studies of laboratory exercise-heat stress (see Snape et al[15] and Stacey et al,[16] also featuring complete methods). Favourable opinions were issued from Leeds Beckett University Research Ethics Committee (Study 1, number 84895) and the United Kingdom (UK) Ministry of Defence REC (Study 2, number 1030/MODREC/19). Written informed consent was obtained from all participants in the study. The Declaration of Helsinki, 2024, was respected throughout. Study 1 outline Twenty participants (18 males, four females) underwent a Heat Stress Test (HST) of 45 min fixed-intensity exercise cycle ergometry (Wattbike, Atom X, Nottingham, UK) in an environmental chamber (32.0 ± 0.3 °C, 71 ± 4% relative humidity). Core body temperature (Tc) was monitored at 2.5-min intervals, by rectal thermistor probe. Resting (PRE) and immediate post-HST (POST) blood samples were co-ordinated with nude body mass measurement. Study 2 outline Twenty-five entrants to Brighton Marathon 2022 were matched as closely as possible to Study 1 participants. Exclusion criteria included traumatic loss of consciousness in the preceding four weeks. Anthropometry (including minimally clothed body mass) and blood tests were taken the day prior to the event (Baseline, B). Participants received two ingestible thermometric capsules for Tc sampling 30 s -1 . Body mass was re-measured and further blood tests were taken < 30 min after finishing (timepoint T0). In participants available next-day, blood sampling was repeated close to 24 h post-marathon (T24). Sample processing and analysis Blood collected into EDTA tubes was centrifuged within 10 minutes (minimum 10 min at 2683 g). Aliquoted plasma was stored at −80◦C and thawed/analysed < 6 weeks after collection. GFAP and UCHL1 were measured both by Alinity iSTAT (Abbott Laboratories, Illinois, US); results henceforth described as CARTRIDGE) and (GFAP: Oxford Biosystems, Abingdon, UK; UCH-L1: R & D Systems Europe, Abingdon, UK; henceforth referred to as BENCH). Statistical analysis Using GraphPad Prism (Version 8.1.0), all data were assessed for normality and expressed as mean ± SD or median [IQR]. Where assay results fell below the LLOQ, a value 50% of the LLOQ was assumed. Comparisons were by t-test (parametric data) or Wilcoxon test (non-parametric paired data) or Mann-Whitney test (non-paired non-parametric data). One-way ANOVA assessed variation in GFAP and UCHL-1 in Study 2 across B-T0-T24, with post hoc corrections for multiple comparisons. Bland Altman plots were constructed to examine variation between BENCH and CARTRIDGE. Significance was set to alpha=0.05. Declarations Author contributions MJS, DW and BW drafted the manuscript. All other authors approved the final version. All authors contributed to study design, sample acquisition, data analysis and interpretation of results. Acknowledgements Table of Coinvestigators Hodgson, Luke Brighton Marathon Research Group Brighton & Sussex Medical School, Brighton, UK Jenkins, Rhys Brighton Marathon Research Group Research & Clinical Innovation, United Kindgom Defence Medical Services Galloway, Rob Brighton Marathon Research Group Brighton & Sussex Medical School, Brighton, UK Weller, Carrie Brighton Marathon Research Group Brighton & Sussex Medical School, Brighton, UK Richardson, Alan J Brighton Marathon Research Group School of Sport and Health Sciences, University of Brighton, UK Greenhalgh, Rob Brighton Marathon Research Group University Hospitals Sussex NHS Foundation Trust Muniz-Pardos, Borja EXER-GENUD Research Group, Faculty of Health and Sport Sciences, University of Zaragoza, Zaragoza, Spain Racinais, Sebastien Environmental Stress Unit, CREPS Montpellier – Font Romeu, Montpellier, France Guppy, Fergus School of Energy, Geoscience, Infrastructure and Society, Institute of Life and Earth Sciences, Heriot-Watt University, Edinburgh, UK Pitsiladis, Asimina Human Telemetrics, London, UK Bundy, Ross Human Telemetrics, London, UK Miller, Mike World Olympians Association, Lausanne, Switzerland Data Availability Primary aims of each study were reported separately. 15,16 Only marathon enzyme linked immunosorbent assay (ELISA) measures overlap the present work. Anonymised data not published within the present article will be made available by request from any qualified investigator. Competing Interests Statement There are no competing interests. Funding Funding was received from the Surgeon General of the UK Defence Medical Services. References Reyes, J., Spitz G, Major, B.P., O'Brien, W.T., Giesler, L.P., Bain, J.W.P., et al. Utility of acute and subacute blood biomarkers to assist diagnosis in CT negative isolated mild traumatic brain injury. Neurology . 2023;101(20):e1992-e2004. Korley, F.K., Datwyler, S.A., Jain, S., Sun, X., Beligere, G., Chandran., et al. Comparison of GFAP and UCH-L1 Measurements from Two Prototype Assays: The Abbott i-STAT and ARCHITECT Assays. Neurotrauma Rep . 2021 Apr 7;2(1):193-199. Yue, J.K., Yuh, E.L., Korley, F.K., Winkler, E.A., Sun, X., Puffer, R.C., et al. (2019). Association between plasma GFAP concentrations and MRI abnormalities in patients with CT-negative traumatic brain injury in the TRACK-TBI cohort: a prospective multicentre study. Lancet Neurol . 18, 953–961. Feigin, V.L., Theadom, A., Barker-Collo, S., Starkey, N.J., McPherson, K., et al. Incidence of traumatic brain injury in New Zealand: a population-based study. Lancet Neurol . 2013 Jan;12(1):53-64. doi: 10.1016/S1474-4422(12)70262-4. Epub 2012 Nov 22. PMID: 23177532 Jennett, B., Frankovyski, R.F.. The epidemiology of head injury. In: Handbook of Clinical Neurology, Braakman R (Ed), Elsevier, New York 1990. Vol 13, p.1. O'Brien, W.T., Hickey, J.W., Mutimer, S., Evans, L.J., Colman, B.D., Xie, B., et al. Next-Day Serum Glial Fibrillary Acidic Protein Levels to Aid Diagnosis of Sport-Related Concussion. Neurology. 2025 Mar 11;104(5):e210308. doi: 10.1212/WNL.0000000000210308. Bazarian, J.J., Abar, B., Merchant-Borna, K., Pham, D.L., Rozen, E., Mannix, R., et al. Effects of Physical Exertion on Early Changes in Blood-Based Brain Biomarkers: Implications for the Acute Point of Care Diagnosis of Concussion. J Neurotrauma. 2023 Apr;40(7-8):693-705. doi: 10.1089/neu.2022.0267. Uddin, N., Scott, J., Nixon, J., Patterson, S.D., Kidgell, D., Pearce, A.J., et al. The effects of exercise, heat-induced hypo-hydration and rehydration on blood-brain-barrier permeability, corticospinal and peripheral excitability. Eur J Appl Physiol. 2025 Feb;125(2):535-550. doi: 10.1007/s00421-024-05616-x. Whitehouse, D.P., Wilson, L., Czeiter, E., Buki, A., Wang, K.K.W., von Steinbüchel, N., et al. Association of Blood-Based Biomarkers and 6-Month Patient-Reported Outcomes in Patients With Mild TBI: A CENTER-TBI Analysis. Neurology. 2025 Jan 14;104(1):e210040. doi: 10.1212/WNL.0000000000210040. Bishop P, Rocca D, Henley JM. Ubiquitin C-terminal hydrolase L1 (UCH-L1): structure, distribution and roles in brain function and dysfunction. Biochemical Journal . 2016;473(16):2453-62. Watson, P., Black, K.E., Clark, S.C., Maughan, R.J. Exercise in the heat: effect of fluid ingestion on blood-brain barrier permeability . Med Sci Sports Exerc. 2006 Dec;38(12):2118-24. doi: 10.1249/01.mss.0000235356.31932.0a. FDA (2024) 510 (k) substantial equivalence determination decision summary. Available from: https://www.accessdata.fda.gov/cdrh_docs/reviews/K201778.pdf [Accessed 07/10/25, 2025] Bazarian, J.J., Welch, R.D., Caudle, K., Jeffrey, C.A., Chen, J.Y., Chandran, R. Accuracy of a rapid glial fibrillary acidic protein/ubiquitin carboxyl-terminal hydrolase L1 test for the prediction of intracranial injuries on head computed tomography after mild traumatic brain injury. Acad Emerg Med. 2021 Nov;28(11):1308-1317. Papa, L., Brophy, G.M., Alvarez, W., Hirschl, R., Cress, M., Weber, K., et al. Sex differences in time course and diagnostic accuracy of GFAP and UCH-L1 in trauma patients with mild traumatic brain injury. Sci Rep. 2023;13:11833. doi: 10.1038/s41598-023-38804-4. Snape, D., Wainwright, B., Parsons, I.T., Stacey, M.J., Woods, D.R., O'Hara, J. Seven days of mixed-method heat acclimation improved markers of cardiovascular and fluid-regulatory strain during exercise-heat stress . Exp Physiol. 2025 Aug 27. doi: 10.1113/EP092681. Stacey, M.J., Leckie, T., Fitzpatrick, D., Hodgson, L., Barden, A., Jenkins, R., et al. Neurobiomarker and body temperature responses to recreational marathon running. J Sci Med Sport. 2023 Nov;26(11):566-573. doi: 10.1016/j.jsams.2023.09.011. Additional Declarations No competing interests reported. Supplementary Files SupplementaryFigure1.tiff Supplementary Figure 1. Glial Fibrillary Acid Protein (GFAP) and Ubiquitin Carboxyl-terminal Hydrolase isozyme L1 measured by ELISA (BENCH) in 25 participants who successfully completed the marathon, sampled at rested baseline (B), upon event completion (T0, n=25) and next-day (T24, n=7). LLOQ, lower limit of quantification; TBI, Traumatic Brain Injury (decision threshold). Cite Share Download PDF Status: Published Journal Publication published 10 Feb, 2026 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 27 Nov, 2025 Reviews received at journal 25 Nov, 2025 Reviews received at journal 20 Nov, 2025 Reviewers agreed at journal 12 Nov, 2025 Reviewers agreed at journal 11 Nov, 2025 Reviewers agreed at journal 06 Nov, 2025 Reviewers invited by journal 05 Nov, 2025 Editor assigned by journal 05 Nov, 2025 Editor invited by journal 03 Nov, 2025 Submission checks completed at journal 31 Oct, 2025 First submitted to journal 31 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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08:34:01","extension":"tiff","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":114168,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryFigure1.tiff","url":"https://assets-eu.researchsquare.com/files/rs-7970895/v1/728d806d606ea6abb4a0efca.tiff"},{"id":96157209,"identity":"1e3bb32d-9aac-409c-8fdd-a422684da68b","added_by":"auto","created_at":"2025-11-18 08:34:01","extension":"xml","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":64762,"visible":true,"origin":"","legend":"","description":"","filename":"c01492e1e8b940dc8f91d4c7424ee6721enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7970895/v1/9d83228491f04353b1523cb9.xml"},{"id":96251950,"identity":"72f6c4d8-2d34-42dd-9df6-625b832096a8","added_by":"auto","created_at":"2025-11-19 07:40:13","extension":"tiff","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":120500,"visible":true,"origin":"","legend":"","description":"","filename":"Figure1.tiff","url":"https://assets-eu.researchsquare.com/files/rs-7970895/v1/087690cbc83b8fe7afe267cb.tiff"},{"id":96157211,"identity":"a9c344d5-1a2d-4202-9c63-e8a3abfe6e68","added_by":"auto","created_at":"2025-11-18 08:34:01","extension":"tiff","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":55676,"visible":true,"origin":"","legend":"","description":"","filename":"Figure2.tiff","url":"https://assets-eu.researchsquare.com/files/rs-7970895/v1/774ab6f536e465b02b867ae6.tiff"},{"id":96157216,"identity":"a7688b59-352b-4b3c-8a9d-fc7930ca6143","added_by":"auto","created_at":"2025-11-18 08:34:01","extension":"png","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":29060,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineFigure1.png","url":"https://assets-eu.researchsquare.com/files/rs-7970895/v1/86e29b495232b998913faff0.png"},{"id":96157212,"identity":"6e31c3f0-3c69-4400-a1dc-e13c2b943dae","added_by":"auto","created_at":"2025-11-18 08:34:01","extension":"png","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":24398,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineFigure2.png","url":"https://assets-eu.researchsquare.com/files/rs-7970895/v1/6d875a6dd5307427fa71e229.png"},{"id":96157214,"identity":"804533c8-426b-47de-9832-49e16756af4e","added_by":"auto","created_at":"2025-11-18 08:34:01","extension":"xml","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":60370,"visible":true,"origin":"","legend":"","description":"","filename":"c01492e1e8b940dc8f91d4c7424ee6721structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7970895/v1/4cf666ecf4d3a25ab8f7ef1e.xml"},{"id":96157217,"identity":"b9bc708a-9b10-43d0-a642-bbdc28d384de","added_by":"auto","created_at":"2025-11-18 08:34:01","extension":"html","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":74317,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7970895/v1/f29112da3824796c44b5da70.html"},{"id":96157207,"identity":"c57f864a-b7f5-4d11-8459-f76e25638cf9","added_by":"auto","created_at":"2025-11-18 08:34:01","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":127606,"visible":true,"origin":"","legend":"\u003cp\u003eGlial Fibrillary Acid Protein (GFAP) and Ubiquitin Carboxyl-terminal Hydrolase isozyme L1 measured by iSTAT Alinity (CARTRIDGE) in 25 participants who successfully completed the marathon, sampled at rested baseline (B), upon event completion (T0, n=25) and next-day (T24, n=7). \u003csup\u003e§§§\u003c/sup\u003eP\u0026lt;0.0001, B vs T0. LLOQ, lower limit of quantification; TBI, Traumatic Brain Injury (decision threshold). Values below the LLOQ expressed as 50% LLOQ.\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-7970895/v1/46d7c05cc80e30a3db4ea1e4.png"},{"id":96250803,"identity":"6ee1c640-5948-4837-9d21-c4fae8e5a3c0","added_by":"auto","created_at":"2025-11-19 07:39:01","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":60891,"visible":true,"origin":"","legend":"\u003cp\u003eBland Altman plot of ubiquitin Carboxyl-terminal Hydrolase isozyme L1 measured by iSTAT Alinity (CARTRIDGE) and ELISA (BENCH) in 25 participants who successfully completed the marathon, sampled upon event completion (T0).\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-7970895/v1/f5f9bccc0806e5479ad42ca6.png"},{"id":102785756,"identity":"4ed36204-c257-4cf0-a3e9-060439f45477","added_by":"auto","created_at":"2026-02-16 16:09:43","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":639582,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7970895/v1/b8c82869-c410-467c-a446-6e11a3d8a343.pdf"},{"id":96157204,"identity":"61036a21-3911-42f2-970a-12634a2f6194","added_by":"auto","created_at":"2025-11-18 08:34:01","extension":"tiff","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":114168,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary Figure 1. Glial Fibrillary Acid Protein (GFAP) and Ubiquitin Carboxyl-terminal Hydrolase isozyme L1 measured by ELISA (BENCH) in 25 participants who successfully completed the marathon, sampled at rested baseline (B), upon event completion (T0, n=25) and next-day (T24, n=7). LLOQ, lower limit of quantification; TBI, Traumatic Brain Injury (decision threshold).\u003c/p\u003e","description":"","filename":"SupplementaryFigure1.tiff","url":"https://assets-eu.researchsquare.com/files/rs-7970895/v1/303a546da146371c3adedf0e.tiff"}],"financialInterests":"No competing interests reported.","formattedTitle":"Near-care assay of plasma glial fibrillary acid protein and ubiquitin carboxyl- terminal hydrolase isozyme L1: impact of exercise-heat stress","fulltext":[{"header":"Introduction","content":"\u003cp\u003eIn distinguishing significant brain lesions consequent upon Traumatic Brain Injury (TBI), quantification of biomarkers indicative of neurological processes (neurobiomarkers) in peripheral blood presents a less hazardous and potentially cheaper alternative to computed tomography (CT).[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e] Glial fibrillary acid protein (GFAP) and ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1) have been approved for dual assay as a rapid near-care tool to exclude more severe TBI. The Alinity iSTAT provides an automated, cartridge-based system, generating semi-quantitative results within 15 minutes and showing close correlation with benchtop analytical platforms.[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u003c/p\u003e\u003cp\u003eThe wider study in which relationships between cartridge near-care and benchtop laboratory assays were derived categorised only 2.5% of patients as suffering from exercise-associated TBI,[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] yet recreational and occupational activities account up to 20% of all cases.[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] Given the prevalence of TBI in physically demanding and thermally stressful environments, and more recent findings that physical activity may differentially influence each neurobiomarker,[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] it is important to establish whether prolonged exercise and heat exposure can independently impact decision thresholds on the Alinity. Thus the aim of this study was to establish whether GFAP and UCHL1 responses would vary between shorter duration exercise performed in the laboratory, and upon more prolonged exercise-heat stress in a field environment.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eBaseline volunteer characteristics are displayed in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows physiological responses to each exposure.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eBaseline (pre-exercise/-acclimatisation) volunteer characteristics for laboratory and field studies.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003en\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eAge\u003c/p\u003e\u003cp\u003e(y)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eFemale (%)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eHeight\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eWeight\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003eBSA (m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLaboratory\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e30\u0026thinsp;\u0026plusmn;\u0026thinsp;7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e25.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e\u003cp\u003e177\u0026thinsp;\u0026plusmn;\u0026thinsp;8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e\u003cp\u003e73.3\u0026thinsp;\u0026plusmn;\u0026thinsp;12.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e\u003cp\u003e1.90\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eField\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e25\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e31\u0026thinsp;\u0026plusmn;\u0026thinsp;5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e11.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e\u003cp\u003e178\u0026thinsp;\u0026plusmn;\u0026thinsp;8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e\u003cp\u003e75.4\u0026thinsp;\u0026plusmn;\u0026thinsp;12.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e\u003cp\u003e1.93\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePhysiological responses to 45 min Heat Stress Test (Study 1) and marathon participation (Study 2, 231\u0026thinsp;\u0026plusmn;\u0026thinsp;34 min duration).\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eStudy 1\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eStudy 2\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP-value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eResting Tc\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e37.08 [36.91, 37.21]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e37.29 [36.98, 37.55]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.0663\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePost-exercise Tc\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e38.42 [38.33, 38.82]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e38.66 [38.16, 39.15]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.4128\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean Tc\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e37.83 {37.71, 37.99]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e38.18 [37.73, 38.72]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.0311\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaximum Tc rise\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1.31 [1.18, 1.76]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e1.87 [1.53, 2.31]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.0005\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBody mass change (kg)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e-1.25\u0026thinsp;\u0026plusmn;\u0026thinsp;0.27\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e-1.3 [-0.35, -2.35]\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e0.7507\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"4\"\u003eSupplementary Fig.\u0026nbsp;1. Glial Fibrillary Acid Protein (GFAP) and Ubiquitin Carboxyl-terminal Hydrolase isozyme L1 measured by ELISA (BENCH) in 25 participants who successfully completed the marathon, sampled at rested baseline (B), upon event completion (T0, n\u0026thinsp;=\u0026thinsp;25) and next-day (T24, n\u0026thinsp;=\u0026thinsp;7). LLOQ, lower limit of quantification; TBI, Traumatic Brain Injury (decision threshold).\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eIn Study 1, CARTRIDGE for both GFAP and UCHL1 remained below LLOQ, with no values challenging respective TBI decision thresholds (30 \u0026micro;g.L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 360 \u0026micro;g.L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). BENCH GFAP was unchanged with HST (0.025 [0.025, 0.025] vs 0.025 [0.025, 0.058] pmol.L\u003csup\u003e\u0026minus;\u0026thinsp;1,\u003c/sup\u003e P\u0026thinsp;=\u0026thinsp;0.5156], whereas BENCH UCHL1 (230.3 [19.6, 1062.0] vs 170.6 [19.60, 619.30] pmol.L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, P\u0026thinsp;=\u0026thinsp;0.0093] decreased modestly.\u003c/p\u003e\u003cp\u003eIn Study 2, the CARTRIDGE decision threshold for GFAP was breached on one occasion only, in T24 sampling, with all other values remaining\u0026thinsp;\u0026lt;\u0026thinsp;LLOQ and no significant variation overall. For UCHL1, 18/25 runners exceeded the corresponding CARTRIDGE decision threshold upon marathon completion (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). In BENCH measures, both GFAP and UCHL1 were unchanged with marathon participation (Supplementary Fig.\u0026nbsp;1).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eBland Altman plot of log UCHL1 post -marathon (T0) is shown at Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e (BENCH vs CARTRIDGE). Bias was 1.39\u0026thinsp;\u0026plusmn;\u0026thinsp;1.46 (95% limits of agreement \u0026minus;\u0026thinsp;1.474 to 4.255), with no significant correlation between methods (P\u0026thinsp;=\u0026thinsp;0.1834).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eAcross two studies of shorter and longer duration exercise, we have demonstrated differential responses in neurobiomarkers quantified by near-care testing. While CARTRIDGE measures of GFAP and UCHL1 remained below LLOQ with a shorter cycle ergometry protocol in the heat, significant variation was observed for UCHL1 with longer duration running, sufficient to breach the TBI cut-off value in a majority of participants.\u003c/p\u003e\u003cp\u003eIn the first 24 h following TBI, elevated plasma UCHL1 associated with worse functional outcomes and poorer quality of life.[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] However even in the absence of TBI, delayed UCHL1 rise has been reported post-exercise, with UCHL1 increasing in proportion to the duration of the bout (aerobic/anaerobic conditioning over 40 to 196 minutes),[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] and progressively throughout recovery (immediately post-3 h submaximal cvcling, and again at 2 and 24 h).[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] Both protocols employed a benchtop ELISA rather than the iSTAT, nevertheless apparent failure of UCHL1 values to challenge decision threshold associated with the latter provided relative reassurance to clinical application in the context of prior exercise.\u003c/p\u003e\u003cp\u003eHowever in the present work sampling close to marathon completion revealed greater elevation, with median CARTRIDGE UCHL1 of 462 mcg.L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e substantially exceeding the iSTAT decision threshold of 360 mcg.L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Factors that may have favoured relative increase in UCHL1 in Study 2 versus Study 1 and previous work may include the longer time window available for release of UCHL1 from neurons and extracranial sources, such as gonadal tissues;[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] greater CNS insult from torsional forces increased with running versus static laboratory cycling; relative increase in blood brain barrier (BBB) permeability to enhance UCHL1 entry into the peripheral circulation, with progressive BBB opening observed under exercise at higher core body temperature and with dehydration;[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] and impaired UCHL1 clearance by the liver and spleen, due to reduced blood flow with exercise and thermoregulation.\u003c/p\u003e\u003cp\u003eAlternatively, it is conceivable that the increase in CARTRIDGE UCHL1 with marathon participation was artefactual and perhaps related to interfering substances appearing relative to settings of increased physical stress, or to freeze/thawing. However, we deem this less likely, because (1) many of the TBI cases recruited to the validation work for the UCHL1 CARTRIDGE assay suffered TBI in the setting of polytrauma, with multiple other body tissues affected and associated physiological strain from haemorrhage (2) in the FDA approval process, no elevation in UCHL1 was observed from assay cross-talk with any other tested substance, including caffeine, acetaminophen and non-steroidal anti-inflammatory agents (i.e. common ergogenic aids used by athletes)[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] and (3) analysis was achieved within the post-collection time window recommended by the manufacturer, and the stability of frozen plasma specimens relative to fresh was established as part of the FDA submission process.[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/p\u003e\u003cp\u003eConsidering other potential limitations of our work, we acknowledge under-representation of female participants in the study, relative to the general population, though males are more commonly head-injured, with a sex ratio between 2.0:1 and 2.8:1 likely reflecting greater participation of men in high-risk activities that lead to TBIs, including those involving exercise and thermal stress. It does appear that UCHL1 in peripheral blood is slightly higher in males than females, both in TBI and in health,[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] therefore women may not show such a bias as men when the Alinity iSTAT is used soon after physical activity. The age of our study cohorts was also relatively young (study 1: 30\u0026thinsp;\u0026plusmn;\u0026thinsp;7 years ; study 2, 31\u0026thinsp;\u0026plusmn;\u0026thinsp;5 years, Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), though again approximately one-half of all patients with mild TBI are between the ages of 15 and 34 years,[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] and these are exactly the patients who would benefit most from avoiding ionising radiation (compared with older individuals suffering trips and mechanical falls, who have less concern for lifetime irradiation effects).\u003c/p\u003e\u003cp\u003eThe timespan within which diagnostics inform clinical pathways is becoming compressed by advancements in available technologies, including the recent market release of whole blood assay for GFAP/UCHL1 on the iSTAT Alinity. We conclude that caution should be exercised in the clinical interpretation of near- or point-of-care assays where prolonged prior exercise-heat stress may exist, and that further research is needed in this area.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cem\u003eStandard Protocol Approvals, Registrations, and Patient Consents\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eIndividual institutional approvals were granted separately to studies of laboratory exercise-heat stress (see Snape et al[15] and Stacey et al,[16] also featuring complete methods). Favourable opinions were issued from Leeds Beckett University Research Ethics Committee (Study 1, number 84895) and the United Kingdom (UK) Ministry of Defence REC (Study 2, number 1030/MODREC/19). \u0026nbsp;Written informed consent was obtained from all participants in the study. The Declaration of Helsinki, 2024, was respected throughout.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eStudy 1 outline\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eTwenty participants (18 males, four females) underwent a Heat Stress Test (HST) of 45 min fixed-intensity exercise cycle ergometry (Wattbike, Atom X, Nottingham, UK) in an environmental chamber (32.0 \u0026plusmn; 0.3 \u0026deg;C, 71 \u0026plusmn; 4% relative humidity). Core body temperature (Tc) was monitored at 2.5-min intervals, by rectal thermistor probe. Resting (PRE) and immediate post-HST (POST) blood samples were co-ordinated with nude body mass measurement.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eStudy 2 outline\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eTwenty-five entrants to Brighton Marathon 2022 were matched as closely as possible to Study 1 participants. Exclusion criteria included traumatic loss of consciousness in the preceding four weeks. Anthropometry (including minimally clothed body mass) and blood tests were taken the day prior to the event (Baseline, B). Participants received two ingestible thermometric capsules for Tc sampling 30 s\u003csup\u003e-1\u003c/sup\u003e. Body mass was re-measured and further blood tests were taken \u003cu\u003e\u0026lt;\u003c/u\u003e30 min after finishing (timepoint T0). In participants available next-day, blood sampling was repeated close to 24 h post-marathon (T24).\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eSample processing and analysis\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eBlood collected into EDTA tubes was centrifuged within 10 minutes (minimum 10 min at 2683 g). Aliquoted plasma was stored at \u0026minus;80◦C and thawed/analysed \u003cu\u003e\u0026lt;\u003c/u\u003e6 weeks after collection. GFAP and UCHL1 were measured both by Alinity iSTAT (Abbott Laboratories, Illinois, US); results henceforth described as CARTRIDGE) and (GFAP: Oxford Biosystems, Abingdon, UK; UCH-L1: R \u0026amp; D Systems Europe, Abingdon, UK; henceforth referred to as BENCH).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eStatistical analysis\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eUsing GraphPad Prism (Version 8.1.0), all data were assessed for normality and expressed as mean \u0026plusmn; SD or median [IQR]. Where assay results fell below the LLOQ, a value 50% of the LLOQ was assumed. Comparisons were by t-test (parametric data) or Wilcoxon test (non-parametric paired data) or Mann-Whitney test (non-paired non-parametric data). One-way ANOVA assessed variation in GFAP and UCHL-1 in Study 2 across B-T0-T24, with post hoc corrections for multiple comparisons. Bland Altman plots were constructed to examine variation between BENCH and CARTRIDGE. Significance was set to alpha=0.05.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMJS, DW and BW drafted the manuscript. All other authors approved the final version. All authors contributed to study design, sample acquisition, data analysis and interpretation of results.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTable of Coinvestigators\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eHodgson, Luke\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 412px;\"\u003e\n \u003cp\u003eBrighton Marathon Research Group\u003c/p\u003e\n \u003cp\u003eBrighton \u0026amp; Sussex Medical School, Brighton, UK\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eJenkins, Rhys\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 412px;\"\u003e\n \u003cp\u003eBrighton Marathon Research Group\u003c/p\u003e\n \u003cp\u003eResearch \u0026amp; Clinical Innovation, United Kindgom Defence Medical Services\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eGalloway, Rob\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 412px;\"\u003e\n \u003cp\u003eBrighton Marathon Research Group\u003c/p\u003e\n \u003cp\u003eBrighton \u0026amp; Sussex Medical School, Brighton, UK\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eWeller, Carrie\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 412px;\"\u003e\n \u003cp\u003eBrighton Marathon Research Group\u003c/p\u003e\n \u003cp\u003eBrighton \u0026amp; Sussex Medical School, Brighton, UK\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eRichardson, Alan J\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 412px;\"\u003e\n \u003cp\u003eBrighton Marathon Research Group\u003c/p\u003e\n \u003cp\u003eSchool of Sport and Health Sciences, University of Brighton, UK\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eGreenhalgh, Rob\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 412px;\"\u003e\n \u003cp\u003eBrighton Marathon Research Group\u003c/p\u003e\n \u003cp\u003eUniversity Hospitals Sussex NHS Foundation Trust\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eMuniz-Pardos, Borja\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 412px;\"\u003e\n \u003cp\u003eEXER-GENUD Research Group, Faculty of Health and Sport Sciences, University of Zaragoza, Zaragoza, Spain\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eRacinais, Sebastien\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 412px;\"\u003e\n \u003cp\u003eEnvironmental Stress Unit, CREPS Montpellier \u0026ndash; Font Romeu, Montpellier, France\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eGuppy, Fergus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 412px;\"\u003e\n \u003cp\u003eSchool of Energy, Geoscience, Infrastructure and Society, Institute of Life and Earth Sciences, Heriot-Watt University, Edinburgh, UK\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003ePitsiladis, Asimina\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 412px;\"\u003e\n \u003cp\u003eHuman Telemetrics, London, UK\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eBundy, Ross\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 412px;\"\u003e\n \u003cp\u003eHuman Telemetrics, London, UK\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003eMiller, Mike\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 412px;\"\u003e\n \u003cp\u003eWorld Olympians Association, Lausanne, Switzerland\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePrimary aims of each study were reported separately.\u003csup\u003e15,16\u003c/sup\u003e Only marathon enzyme linked immunosorbent assay (ELISA) measures overlap the present work. Anonymised data not published within the present article will be made available by request from any qualified investigator.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests Statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere are no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFunding was received from the Surgeon General of the UK Defence Medical Services.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eReyes, J., Spitz G, Major, B.P., O\u0026apos;Brien, W.T., Giesler, L.P., Bain, J.W.P., et al. Utility of acute and subacute blood biomarkers to assist diagnosis in CT negative isolated mild traumatic brain injury.\u0026nbsp;\u003cem\u003eNeurology\u003c/em\u003e. 2023;101(20):e1992-e2004.\u003c/li\u003e\n \u003cli\u003eKorley, F.K., Datwyler, S.A., Jain, S., Sun, X., Beligere, G., Chandran., et al. 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In: Handbook of Clinical Neurology, Braakman R (Ed), Elsevier, New York 1990. Vol 13, p.1.\u003c/li\u003e\n \u003cli\u003eO\u0026apos;Brien, W.T., Hickey, J.W., Mutimer, S., Evans, L.J., Colman, B.D., Xie, B., et al. Next-Day Serum Glial Fibrillary Acidic Protein Levels to Aid Diagnosis of Sport-Related Concussion.\u0026nbsp;\u003cem\u003eNeurology.\u003c/em\u003e 2025 Mar 11;104(5):e210308. doi: 10.1212/WNL.0000000000210308.\u003c/li\u003e\n \u003cli\u003eBazarian, J.J., Abar, B., Merchant-Borna, K., Pham, D.L., Rozen, E., Mannix, R., et al. Effects of Physical Exertion on Early Changes in Blood-Based Brain Biomarkers: Implications for the Acute Point of Care Diagnosis of Concussion.\u0026nbsp;\u003cem\u003eJ Neurotrauma.\u003c/em\u003e 2023 Apr;40(7-8):693-705. doi: 10.1089/neu.2022.0267.\u003c/li\u003e\n \u003cli\u003eUddin, N., Scott, J., Nixon, J., Patterson, S.D., Kidgell, D., Pearce, A.J., et al. 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Exercise in the heat: effect of fluid ingestion on blood-brain barrier permeability\u003cem\u003e. Med Sci Sports Exerc.\u003c/em\u003e 2006 Dec;38(12):2118-24. doi: 10.1249/01.mss.0000235356.31932.0a.\u003c/li\u003e\n \u003cli\u003eFDA (2024) 510 (k) substantial equivalence determination decision summary. Available from: https://www.accessdata.fda.gov/cdrh_docs/reviews/K201778.pdf [Accessed 07/10/25, 2025]\u003c/li\u003e\n \u003cli\u003eBazarian, J.J., Welch, R.D., Caudle, K., Jeffrey, C.A., Chen, J.Y., Chandran, R. Accuracy of a rapid glial fibrillary acidic protein/ubiquitin carboxyl-terminal hydrolase L1 test for the prediction of intracranial injuries on head computed tomography after mild traumatic brain injury.\u0026nbsp;\u003cem\u003eAcad Emerg Med.\u003c/em\u003e 2021 Nov;28(11):1308-1317.\u003c/li\u003e\n \u003cli\u003e\u0026nbsp;Papa, L., Brophy, G.M., Alvarez, W., Hirschl, R., Cress, M., Weber, K., et al. Sex differences in time course and diagnostic accuracy of GFAP and UCH-L1 in trauma patients with mild traumatic brain injury.\u0026nbsp;\u003cem\u003eSci Rep.\u003c/em\u003e 2023;13:11833. doi: 10.1038/s41598-023-38804-4.\u003c/li\u003e\n \u003cli\u003eSnape, D., Wainwright, B., Parsons, I.T., Stacey, M.J., Woods, D.R., O\u0026apos;Hara, J. Seven days of mixed-method heat acclimation improved markers of cardiovascular and fluid-regulatory strain during exercise-heat stress\u003cem\u003e. Exp Physiol.\u003c/em\u003e 2025 Aug 27. doi: 10.1113/EP092681.\u003c/li\u003e\n \u003cli\u003eStacey, M.J., Leckie, T., Fitzpatrick, D., Hodgson, L., Barden, A., Jenkins, R., et al. Neurobiomarker and body temperature responses to recreational marathon running.\u0026nbsp;\u003cem\u003eJ Sci Med Sport.\u003c/em\u003e 2023 Nov;26(11):566-573. doi: 10.1016/j.jsams.2023.09.011.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-7970895/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7970895/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjectives\u003c/h2\u003e\u003cp\u003eNeurobiomarkers measured in peripheral blood can supplement management strategies following Traumatic Brain Injury (TBI). Dual-assay of glial fibrillary acid protein (GFAP) and ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1) is FDA-approved for assessing, at near-care, a decision threshold for post-TBI neuroimaging. As physical activity and thermal strain often accompany TBI-prone activities, we investigated whether each molecule\u0026rsquo;s quantification - and, by extension, clinical decisions - could be influenced by exercise-heat stress.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eIn healthy volunteers monitored continuously for body core temperature (Tc), we used the i-STAT Alinity\u0026reg; to investigate plasma GFAP and UCHL1 responses to exercise in the laboratory (three female, seven male trained participants, cycling for 45 min in 32\u0026deg;C) and field (three female and 22 male recreational marathon runners, finishing time 231\u0026thinsp;\u0026plusmn;\u0026thinsp;34 min, peak ambient temperature 11\u0026deg;C).\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eRespective ΔTc overall were 1.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37\u0026deg;C and 1.87 [1.53, 2.31] \u0026deg;C. With laboratory exercise, GFAP and UCHL1 did not exceed the manufacturer\u0026rsquo;s decision threshold. Across the marathon, GFAP was also stable, whereas UCH-L1 more than doubled (200 [200, 200] vs 462 [310, 782] \u0026micro;g.L-1, P\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), breaching the decision threshold for neuroimaging in 18/25 runners.\u003c/p\u003e\u003ch2\u003eDiscussion\u003c/h2\u003e\u003cp\u003eConfounding from more prolonged exercise-heat stress should be considered when managing TBI using near-care assay of UCHL1.\u003c/p\u003e","manuscriptTitle":"Near-care assay of plasma glial fibrillary acid protein and ubiquitin carboxyl- terminal hydrolase isozyme L1: impact of exercise-heat stress","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-18 08:33:56","doi":"10.21203/rs.3.rs-7970895/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-11-27T11:20:49+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-25T17:03:21+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-11-20T18:57:09+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"265312245606429476772312475912594612639","date":"2025-11-12T16:52:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"307260973793996138547035913602231966683","date":"2025-11-11T16:29:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"193313211626533737299391326866621347786","date":"2025-11-06T15:50:02+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-11-05T20:00:47+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-11-05T19:52:42+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-11-03T16:07:52+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-31T15:48:03+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-10-31T15:45:14+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"947adfbb-6267-4c9a-ae60-ba210cb8d263","owner":[],"postedDate":"November 18th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":58051210,"name":"Health sciences/Biomarkers"},{"id":58051211,"name":"Health sciences/Medical research"},{"id":58051212,"name":"Health sciences/Neurology"},{"id":58051213,"name":"Biological sciences/Neuroscience"}],"tags":[],"updatedAt":"2026-02-16T16:07:37+00:00","versionOfRecord":{"articleIdentity":"rs-7970895","link":"https://doi.org/10.1038/s41598-026-38768-1","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2026-02-10 15:57:19","publishedOnDateReadable":"February 10th, 2026"},"versionCreatedAt":"2025-11-18 08:33:56","video":"","vorDoi":"10.1038/s41598-026-38768-1","vorDoiUrl":"https://doi.org/10.1038/s41598-026-38768-1","workflowStages":[]},"version":"v1","identity":"rs-7970895","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7970895","identity":"rs-7970895","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}