{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T09:59:54Z","timestamp":1785405594099,"version":"3.56.0"},"posted":{"date-parts":[[2026,7,23]]},"group-title":"Immunology","reference-count":39,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,7,23]],"date-time":"2026-07-23T00:00:00Z","timestamp":1784764800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"award":["1R41MH138179"],"award-info":[{"award-number":["1R41MH138179"]}],"id":[{"id":"https:\/\/ror.org\/01cwqze88","id-type":"ROR","asserted-by":"publisher"}]},{"award":["P51OD011104"],"award-info":[{"award-number":["P51OD011104"]}],"id":[{"id":"https:\/\/ror.org\/01cwqze88","id-type":"ROR","asserted-by":"publisher"}]},{"award":["1S10OD026833"],"award-info":[{"award-number":["1S10OD026833"]}],"id":[{"id":"https:\/\/ror.org\/01cwqze88","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,7,23]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:p>Expanding access to cellular immune analysis is essential for decentralized clinical care, clinical trials, and population-based research. However, current flow cytometry workflows require rapid processing of fresh blood, proximity to a centralized laboratory, and cold chain logistics. Although dried blood spots (DBS) have transformed decentralized molecular diagnostics, no comparable approach has enabled robust flow cytometric analysis of immune cells.<\/jats:p>\n                <jats:p>Here, we present FlowSpot, a novel platform that enables recovery of leukocytes from DBS and preserves their immunophenotypic characteristics, allowing downstream flow cytometric analysis following ambient-temperature storage and shipment. FlowSpot recovers intact leukocytes while preserving immune cell subset frequencies with strong concordance to fresh whole blood. We demonstrate its clinical utility by enabling remote CD4\u207a T cell immunophenotyping in people living with HIV, showing high agreement with routine clinical measurements across a broad range of CD4\u207a T cell frequencies. Beyond cellular phenotyping, FlowSpot extends immune monitoring to functional profiling by enabling detection of intracellular cytokine responses, including IFN\u03b3, IL-2, and TNF\u03b1 production by CD4\u207a and CD8\u207a T cells following ex vivo PMA\/ionomycin stimulation.<\/jats:p>\n                <jats:p>By overcoming a longstanding barrier to leukocyte recovery from DBS, FlowSpot extends flow cytometry beyond specialized laboratories, expanding access to cellular immune analysis for clinical care, decentralized clinical trials, and population-scale immunology.<\/jats:p>","DOI":"10.64898\/2026.07.20.739622","type":"posted-content","created":{"date-parts":[[2026,7,24]],"date-time":"2026-07-24T10:40:20Z","timestamp":1784889620000},"source":"Crossref","is-referenced-by-count":0,"title":["FlowSpot Enables Decentralized Phenotypic and Functional Cellular Immune Profiling from Dried Blood Spots"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-9468-4374","authenticated-orcid":false,"given":"Rachel","family":"Caddell","sequence":"first","affiliation":[{"name":"Spotted Tech LLC, Bronx, New York"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Suzanne","family":"Adams","sequence":"additional","affiliation":[{"name":"Section of Infectious Diseases, Deming Department of Medicine, School of Medicine Tulane University, LA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2875-902X","authenticated-orcid":false,"given":"David","family":"Mushatt","sequence":"additional","affiliation":[{"name":"Section of Infectious Diseases, Deming Department of Medicine, School of Medicine Tulane University, LA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4514-2681","authenticated-orcid":false,"given":"Monica","family":"Vaccari","sequence":"additional","affiliation":[{"name":"Department of Immunology and Microbiology, School of Medicine Tulane University, New Orleans, LA"},{"name":"Division of Immunology, Tulane National Biomedical Research Center, LA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2597-7147","authenticated-orcid":false,"given":"Marissa","family":"Fahlberg","sequence":"additional","affiliation":[{"name":"Spotted Tech LLC, Bronx, New York"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2026072706204424000_2026.07.20.739622v1.1","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1016\/j.cimid.2018.09.008","article-title":"Immune response biomarkers in human and veterinary research","volume":"59","year":"2018","journal-title":"Comp Immunol Microbiol Infect Dis"},{"key":"2026072706204424000_2026.07.20.739622v1.2","doi-asserted-by":"publisher","DOI":"10.1158\/1078-0432.CCR-10-2234"},{"issue":"8120","key":"2026072706204424000_2026.07.20.739622v1.3","doi-asserted-by":"crossref","first-page":"1076","DOI":"10.1038\/s41586-026-10452-4","article-title":"Non-invasive profiling of the tumour microenvironment with spatial ecotypes","volume":"654","year":"2026","journal-title":"Nature"},{"key":"2026072706204424000_2026.07.20.739622v1.4","doi-asserted-by":"publisher","DOI":"10.1038\/nri3158"},{"issue":"10","key":"2026072706204424000_2026.07.20.739622v1.5","doi-asserted-by":"crossref","first-page":"446","DOI":"10.1007\/s12032-025-03002-x","article-title":"Immune profiling in oncology: bridging the gap between technology and treatment","volume":"42","year":"2025","journal-title":"Med Oncol"},{"key":"2026072706204424000_2026.07.20.739622v1.6","doi-asserted-by":"publisher","DOI":"10.1126\/science.1232910"},{"issue":"4","key":"2026072706204424000_2026.07.20.739622v1.7","doi-asserted-by":"crossref","first-page":"420","DOI":"10.3390\/vaccines13040420","article-title":"Monitoring immune responses to vaccination: A focus on single-cell analysis and associated challenges","volume":"13","year":"2025","journal-title":"Vaccines (Basel"},{"key":"2026072706204424000_2026.07.20.739622v1.8","doi-asserted-by":"crossref","unstructured":"Marshall JL. 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