{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,21]],"date-time":"2026-04-21T09:57:55Z","timestamp":1776765475114,"version":"3.51.2"},"reference-count":0,"publisher":"SMW Supporting Association","issue":"5152","license":[{"start":{"date-parts":[[2021,12,23]],"date-time":"2021-12-23T00:00:00Z","timestamp":1640217600000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Swiss Med Wkly"],"abstract":"<jats:p>BACKGROUND: For patients with difficult venous access after long-term intravenous drug use, rapid point-of-care hepatitis C virus (HCV) RNA quantification in capillary whole\u00a0blood with the Xpert\u00ae HCV Viral Load Fingerstick (VL FS) test (60\u00a0minutes) is a convenient and reliable method for diagnosing chronic HCV infection, monitoring treatment and detecting reinfection. However, an expensive GeneXpert\u00ae\u00a0system must be available on\u00a0site. In decentralised settings with a low case-load, dried blood spot (DBS)\u00a0testing might be an alternative.\nMETHODS: Between December 2019 and January 2021, patients with an indication for HCV RNA quantification and informed consent provided 100 \u00b5l capillary whole\u00a0blood each for on-site Xpert\u00ae HCV VL FS\u00a0testing (reference) and DBS\u00a0testing in the laboratory. For the latter, 100\u00a0\u00b5l blood, collected with an EDTA\u00a0Minivette\u00ae, were transferred to a Whatman\u00ae 903 filter card. After drying for at least 1 hour, the DBS\u00a0sample was packed into a sealable plastic bag with desiccant and sent to the central laboratory of our hospital, where it was stored at \u201320\u00b0C. For HCV RNA extraction, the whole DBS was cut out with an 18-mm\u00a0puncher and transferred into 1.3 ml guanidinium thiocyanate-containing buffer (provided by Cepheid\u00ae). After mixing and incubating at room temperature for 2\u20133 hours, 1 ml supernatant was analysed\u00a0with the Xpert\u00ae HCV VL\u00a0test (105 minutes) (filter paper absorbs 0.3 ml).\nRESULTS: Of 109 paired samples from 67 patients, 38 (34.9%) were positive with the Xpert\u00ae HCV VL FS\u00a0test. Sensitivity and specificity of DBS\u00a0testing were 89.5% (34\/38; 95% confidence interval [CI] 75.9\u201395.8%) and 97.2% (69\/71; 95% CI 90.3\u201399.2%), respectively. The six (5.5%) discordant results (four false\u00a0negative,\u00a0two false\u00a0positive) all were observed in samples with HCV RNA detectable below the limit of quantification after 2\u20138 weeks of pan-genotypic direct-acting antiviral treatment or 5 weeks after acute hepatitis C in a patient clearing HCV spontaneously. Quantifiable results (n = 30; 16 genotype\u00a01, 7 genotype\u00a03, 4 genotype\u00a04, 1 genotype\u00a01a and 3a, 2 unknown; HCV RNA range: 2.74\u20136.66 log IU\/ml) correlated well (R2 = 0.981). On average, uncorrected DBS\u00a0test results were 1.30\u00a0\u00b1\u00a00.14 log IU\/ml lower than Xpert\u00ae HCV VL FS\u00a0test results (~42 \u03bcl instead of the expected 1000\u00a0\u03bcl plasma used). Storage of DBS\u00a0samples at room temperature for 7 days before freezing reduced HCV RNA by 0.29 \u00b1\u00a00.12 log IU\/ml.\nCONCLUSION: HCV RNA can reliably be quantified with the Xpert\u00ae HCV VL\u00a0test in capillary dried blood spot\u00a0samples. Thus, access to capillary HCV RNA quantification for diagnosing chronic HCV infection, monitoring treatment and detecting reinfection can be extended to decentralised settings with a low case load.<\/jats:p>","DOI":"10.4414\/smw.2021.w30089","type":"journal-article","created":{"date-parts":[[2022,1,25]],"date-time":"2022-01-25T13:45:59Z","timestamp":1643118359000},"page":"w30089","source":"Crossref","is-referenced-by-count":5,"title":["HCV RNA quantification in capillary dried blood spots with the Xpert\u00ae HCV Viral Load test for diagnosing chronic HCV infection, monitoring treatment and detecting reinfection"],"prefix":"10.57187","volume":"151","author":[{"given":"Andrea","family":"Bregenzer","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cornelia","family":"Ottiger","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cornelia","family":"Krismer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Karin","family":"Sager","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christoph A.","family":"Fux","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"36756","published-online":{"date-parts":[[2021,12,23]]},"container-title":["Swiss Medical Weekly"],"original-title":[],"link":[{"URL":"https:\/\/smw.ch\/index.php\/smw\/article\/download\/3132\/5229","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/smw.ch\/index.php\/smw\/article\/download\/3132\/5230","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/smw.ch\/index.php\/smw\/article\/download\/3132\/5230","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,1,26]],"date-time":"2023-01-26T22:17:33Z","timestamp":1674771453000},"score":1,"resource":{"primary":{"URL":"https:\/\/smw.ch\/index.php\/smw\/article\/view\/3132"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,12,23]]},"references-count":0,"journal-issue":{"issue":"5152","published-online":{"date-parts":[[2021,12,20]]}},"URL":"https:\/\/doi.org\/10.4414\/smw.2021.w30089","relation":{},"ISSN":["1424-3997"],"issn-type":[{"value":"1424-3997","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,12,23]]}}}