{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T17:09:04Z","timestamp":1785431344803,"version":"3.56.0"},"reference-count":33,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T00:00:00Z","timestamp":1779321600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002322","name":"Coordination for the Improvement of Higher Education Personnel","doi-asserted-by":"crossref","award":["88887.960010\/2024 00"],"award-info":[{"award-number":["88887.960010\/2024 00"]}],"id":[{"id":"10.13039\/501100002322","id-type":"DOI","asserted-by":"crossref"}]},{"award":["88887.960010\/2024 00"],"award-info":[{"award-number":["88887.960010\/2024 00"]}],"id":[{"id":"https:\/\/ror.org\/00x0ma614","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Funda\u00e7\u00e3o Bahiana de Infectologia","award":["FBAI- 03\/25"],"award-info":[{"award-number":["FBAI- 03\/25"]}]},{"award":["FBAI- 03\/25"],"award-info":[{"award-number":["FBAI- 03\/25"]}],"id":[{"id":"https:\/\/ror.org\/01rsw3c42","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.mdpi.com"],"crossmark-restriction":true},"short-container-title":["Viruses"],"abstract":"<jats:p>The proviral load of human T-cell lymphotropic virus type 1 (HTLV-1) is an important biomarker associated with the monitoring and risk stratification of adult T-cell leukemia\/lymphoma (ATL) and HTLV-1-associated myelopathy\/tropical spastic paraparesis (HAM\/TSP). However, the lack of standardized quantification methods limits its broader application. This study evaluated a novel absolute quantification approach based on whole blood volume and compared its performance with established protocols. A total of 66 HTLV-1-infected individuals were analyzed using six qPCR-based methodologies, including volumetric quantification (copies\/\u00b5L) by absolute quantification and the Tameg\u00e3o-Lopes method, as well as normalization per 1000 cells (whole blood, buffy coat, PBMCs, and CD4+ T cells). Association and agreement were assessed using Pearson\u2019s correlation, Bland\u2013Altman analysis, concordance correlation coefficients (CCCs), and Deming regression. Absolute quantification showed strong correlation with both the Tameg\u00e3o-Lopes method and CD4+-based quantification (r = 0.93 and 0.84, respectively; p &lt; 0.001) and high agreement (CCC = 0.866 and 0.811, respectively), with modest systematic bias (\u22120.273 log10 copies\/\u00b5L and 0.115 log10 copies\/103 cells, respectively). Leukocyte-normalized methods showed greater discrepancies, likely due to dilution by uninfected cells. These findings show that quantification based on total blood volume is a simplified, operationally feasible alternative for assessing HTLV-1 proviral load.<\/jats:p>","DOI":"10.3390\/v18050580","type":"journal-article","created":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T15:02:27Z","timestamp":1779375747000},"page":"580","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Whole Blood Volume-Based Absolute Quantification of HTLV-1 Proviral Load: A Comparative Method Evaluation Study"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-0685-5607","authenticated-orcid":false,"given":"Gabriel O.","family":"Franco","sequence":"first","affiliation":[{"name":"Laborat\u00f3rio de Pesquisa em Infectologia (LAPI), Complexo Hospitalar Universit\u00e1rio Professor Edgard Santos, Salvador 40110-060, Brazil"},{"name":"Programa de P\u00f3s-Gradua\u00e7\u00e3o em Medicina e Sa\u00fade (PPgMS), Universidade Federal da Bahia (UFBA), Salvador 40110-060, Brazil"},{"name":"Centro de Forma\u00e7\u00e3o em Biologia Molecular Charles Merieux (CFBMCM), Professor Edgard Santos University Hospital Complex, Salvador 40110-060, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andreas","family":"Stocker","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Pesquisa em Infectologia (LAPI), Complexo Hospitalar Universit\u00e1rio Professor Edgard Santos, Salvador 40110-060, Brazil"},{"name":"Programa de P\u00f3s-Gradua\u00e7\u00e3o em Medicina e Sa\u00fade (PPgMS), Universidade Federal da Bahia (UFBA), Salvador 40110-060, Brazil"},{"name":"Centro de Forma\u00e7\u00e3o em Biologia Molecular Charles Merieux (CFBMCM), Professor Edgard Santos University Hospital Complex, Salvador 40110-060, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1691-6761","authenticated-orcid":false,"given":"Eduardo M.","family":"Netto","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Pesquisa em Infectologia (LAPI), Complexo Hospitalar Universit\u00e1rio Professor Edgard Santos, Salvador 40110-060, Brazil"},{"name":"Programa de P\u00f3s-Gradua\u00e7\u00e3o em Medicina e Sa\u00fade (PPgMS), Universidade Federal da Bahia (UFBA), Salvador 40110-060, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6639-7571","authenticated-orcid":false,"given":"Heliene","family":"Pereira","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Pesquisa em Infectologia (LAPI), Complexo Hospitalar Universit\u00e1rio Professor Edgard Santos, Salvador 40110-060, Brazil"},{"name":"Programa de P\u00f3s-Gradua\u00e7\u00e3o em Medicina e Sa\u00fade (PPgMS), Universidade Federal da Bahia (UFBA), Salvador 40110-060, Brazil"},{"name":"Centro de Forma\u00e7\u00e3o em Biologia Molecular Charles Merieux (CFBMCM), Professor Edgard Santos University Hospital Complex, Salvador 40110-060, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4673-6991","authenticated-orcid":false,"given":"Carlos","family":"Brites","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio de Pesquisa em Infectologia (LAPI), Complexo Hospitalar Universit\u00e1rio Professor Edgard Santos, Salvador 40110-060, Brazil"},{"name":"Programa de P\u00f3s-Gradua\u00e7\u00e3o em Medicina e Sa\u00fade (PPgMS), Universidade Federal da Bahia (UFBA), Salvador 40110-060, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"7415","DOI":"10.1073\/pnas.77.12.7415","article-title":"Detection and isolation of type C retrovirus particles from fresh and cultured lymphocytes of a patient with cutaneous T-cell lymphoma","volume":"77","author":"Poiesz","year":"1980","journal-title":"Proc. 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