Quantification of fibrinaloid clots in plasma from pediatric Long COVID patients using a microfluidic assay

Quantification of fibrinaloid clots in plasma from pediatric Long COVID patients using a microfluidic assay | 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 Quantification of fibrinaloid clots in plasma from pediatric Long COVID patients using a microfluidic assay Daniel Irimia, Kirandeep Gill, Bryan Alvarez-Carcamo, Carly Steifman, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7483367/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Long COVID (LC) impacts one in five children after an acute SARS-CoV-2 infection. Typical LC symptoms include fatigue, brain fog, pain, and shortness of breath, which can significantly impact individuals and society. Moreover, LC may impair school performance and have long-term health and development consequences. However, the diagnosis of LC is often imprecise and cumbersome, delaying appropriate care. To address the LC diagnosis challenges, we focused on fibrinaloid clots (microclots), recently proposed as contributing to LC’s underlying mechanisms. We overcame the limitations of current microclot assessment methods, which are qualitative, by developing a microfluidic device to quantify the number of microclots in patient blood samples. We found significantly higher microclot levels in samples from pediatric LC patients than from healthy children. We evaluated the diagnostic power of the device in a cohort of 45 LC patients and 14 healthy pediatric donors. We estimated a 94% accuracy for the microclot count using the devices, significantly higher than the traditional counting of microclots on slides (66% accuracy). Intriguingly, we found the highest microclot counts in samples from patients with persistent SARS-CoV-2 spike protein in the blood. Further studies will evaluate the utility of the assay as a screening test for Long COVID in larger populations and for assessing treatment responses. Biological sciences/Biotechnology Health sciences/Biomarkers/Diagnostic markers Full Text Additional Declarations There is NO Competing Interest. Supplementary Files SupplementaryVideoV1.mp4 Passive pumping to drive flow in the microfluidic device Cite Share Download PDF Status: Under Review Version 1 posted 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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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7483367","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":513079929,"identity":"c7943eb3-9037-4780-815d-09c250799f6a","order_by":0,"name":"Daniel 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