{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T15:55:48Z","timestamp":1791474948451,"version":"4.3.4"},"reference-count":31,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T00:00:00Z","timestamp":1791331200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T00:00:00Z","timestamp":1791331200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Roche Diagnostics Korea Co., Ltd."},{"id":[{"id":"https:\/\/ror.org\/030nky627","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diagnostics"],"abstract":"<jats:p>Background\/Objectives: The Elecsys HCV Duo immunoassay simultaneously detects HCV core antigen (HCV Ag) and anti-HCV antibodies in a single sample. We evaluated its clinical performance against a standard-of-care reference algorithm of anti-HCV antibody and HCV RNA testing. Methods: We retrospectively analyzed 1332 residual serum or plasma samples tested with reference HCV RNA assays and the Alinity i Anti-HCV assay. Samples were classified as reference-positive, indicating current or past HCV infection (n = 166; 88 RNA+\/Ab+ with active infection and 78 RNA\u2212\/Ab+ with resolved or treated infection), or reference-negative (n = 1166; RNA\u2212\/Ab\u2212), including 1000 randomly selected blood donor samples. All specimens were tested with the Elecsys HCV Duo (cobas\u00ae e 801, Roche Diagnostics). Positive and negative percent agreements (PPA and NPA) were calculated against the combined reference standard. Results were further analyzed by infection status and viral load. No HCV RNA+\/anti-HCV\u2212 (window-period) specimens were available. Results: Overall agreement was high (PPA 98.8% [164\/166; 95% CI, 95.7\u201399.9%]; NPA 99.9% [1165\/1166; 95% CI, 99.5\u2013100.0%]). Agreement of the anti-HCV component with the Alinity i Anti-HCV assay was identical (PPA 98.8%, NPA 99.9%). The HCV Duo Ag component showed a PPA of 60.2% (95% CI, 49.2\u201370.5%) and NPA of 99.0% (95% CI, 98.3\u201399.5%) against HCV RNA detection. The Ag module was also reactive in 12 of 78 (15.4%) RNA\u2212\/Ab+ specimens, all from previously treated patients; thus, 53 of 65 (81.5%) dual Ag\/Ab-reactive specimens had detectable HCV RNA. HCV Ag positivity was highest at HCV RNA \u2265106 IU\/mL (77.4%, 41\/53), compared with 32.1% (9\/28) at 104\u2013106 IU\/mL and 42.9% (3\/7) at &lt;104 IU\/mL. Receiver operating characteristic analysis of the Ag component yielded an area under the curve of 0.920 (95% CI, 0.904\u20130.934). Conclusions: The Elecsys HCV Duo demonstrated high overall agreement with the reference methods, supporting its potential as a single-step screening test for HCV infection. Most, but not all, dual Ag\/Ab-reactive specimens were viremic, so this result may help prioritize anti-HCV-positive individuals for linkage to care; however, the assay does not replace HCV RNA testing, which remains necessary to confirm active infection, particularly in Ag-negative or previously treated individuals. Because no window-period specimens were included, the potential of the assay for earlier detection of acute infection could not be evaluated.<\/jats:p>","DOI":"10.3390\/diagnostics16193239","type":"journal-article","created":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T11:26:53Z","timestamp":1791458813000},"page":"3239","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Clinical Performance of the Elecsys HCV Duo Immunoassay Compared with a Standard-of-Care Algorithm Using Alinity Anti-HCV Screening and HCV RNA Confirmation"],"prefix":"10.3390","volume":"16","author":[{"given":"Jaeeun","family":"Yoo","sequence":"first","affiliation":[{"name":"Department of Laboratory Medicine, Incheon St. Mary\u2019s Hospital, College of Medicine, The Catholic University of Korea, Incheon 21431, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"}]},{"given":"Hye-Sun","family":"Park","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Seoul St. Mary\u2019s Hospital, College of Medicine,  The Catholic University of Korea, Seoul 06591, Republic of Korea"},{"name":"Research and Development Institute for In Vitro Diagnostic Medical Devices, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"given":"JoungOk","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Seoul St. Mary\u2019s Hospital, College of Medicine,  The Catholic University of Korea, Seoul 06591, Republic of Korea"},{"name":"Research and Development Institute for In Vitro Diagnostic Medical Devices, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"given":"Sang-Ik","family":"Cho","sequence":"additional","affiliation":[{"name":"Research and Development Institute for In Vitro Diagnostic Medical Devices, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea"},{"name":"Department of Medical Sciences, Graduate School, The Catholic University of Korea, Seoul 06591, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"}]},{"given":"Seong Hwan","family":"Jo","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Seoul St. Mary\u2019s Hospital, College of Medicine,  The Catholic University of Korea, Seoul 06591, Republic of Korea"},{"name":"Research and Development Institute for In Vitro Diagnostic Medical Devices, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea"},{"name":"Department of Medical Sciences, Graduate School, The Catholic University of Korea, Seoul 06591, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-4687-6717","authenticated-orcid":false,"given":"Seo-A","family":"Park","sequence":"additional","affiliation":[{"name":"Research and Development Institute for In Vitro Diagnostic Medical Devices, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea"},{"name":"Department of Medical Sciences, Graduate School, The Catholic University of Korea, Seoul 06591, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"}]},{"given":"Min-Seok","family":"Kwon","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Seoul St. Mary\u2019s Hospital, College of Medicine,  The Catholic University of Korea, Seoul 06591, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"}]},{"given":"Ae-Ran","family":"Choi","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Seoul St. Mary\u2019s Hospital, College of Medicine,  The Catholic University of Korea, Seoul 06591, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"investigation","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5870-915X","authenticated-orcid":false,"given":"Eun-Jee","family":"Oh","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine, Seoul St. Mary\u2019s Hospital, College of Medicine,  The Catholic University of Korea, Seoul 06591, Republic of Korea"},{"name":"Research and Development Institute for In Vitro Diagnostic Medical Devices, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,10,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"332","DOI":"10.1016\/S2468-1253(22)00386-7","article-title":"Global reporting of progress towards elimination of hepatitis B and hepatitis C","volume":"8","author":"Cui","year":"2023","journal-title":"Lancet Gastroenterol. Hepatol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"17006","DOI":"10.1038\/nrdp.2017.6","article-title":"Hepatitis C virus infection","volume":"3","author":"Manns","year":"2017","journal-title":"Nat. Rev. Dis. Primers"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"j2861","DOI":"10.1136\/bmj.j2861","article-title":"Hepatitis C","volume":"358","author":"Ahmad","year":"2017","journal-title":"BMJ"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"396","DOI":"10.1016\/S2468-1253(21)00472-6","article-title":"Global change in hepatitis C virus prevalence and cascade of care between 2015 and 2020: A modelling study","volume":"7","author":"Blach","year":"2022","journal-title":"Lancet Gastroenterol. Hepatol."},{"key":"ref_5","unstructured":"World Health Organization (2024). Global Hepatitis Report 2024: Action for Access in Low- and Middle-Income Countries, World Health Organization."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"779","DOI":"10.3350\/cmh.2023.0110","article-title":"Core indicators related to the elimination of hepatitis B and C virus infection in South Korea: A nationwide study","volume":"29","author":"Lee","year":"2023","journal-title":"Clin. Mol. Hepatol."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Bhattacharya, D., Aronsohn, A., Price, J., Lo Re, V., and American Association for the Study of Liver Diseases\u2013Infectious Diseases Society of America HCV Guidance Panel (2023). Hepatitis C guidance 2023 update: American Association for the Study of Liver Diseases\u2013Infectious Diseases Society of America recommendations for testing, managing, and treating hepatitis C virus infection. Clin. Infect. Dis., ciad319.","DOI":"10.1093\/cid\/ciad319"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1","DOI":"10.3350\/cmh.2025.0777","article-title":"2025 KASL clinical practice guidelines for management of hepatitis C","volume":"32","author":"Jang","year":"2026","journal-title":"Clin. Mol. Hepatol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1","DOI":"10.15585\/mmwr.rr6902a1","article-title":"CDC recommendations for hepatitis C screening among adults\u2014United States, 2020","volume":"69","author":"Schillie","year":"2020","journal-title":"MMWR. Recomm. Rep."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"766","DOI":"10.15585\/mmwr.mm7228a2","article-title":"Updated operational guidance for implementing CDC\u2019s recommendations on testing for hepatitis C virus infection","volume":"72","author":"Cartwright","year":"2023","journal-title":"MMWR. Morb. Mortal. Wkly. Rep."},{"key":"ref_11","first-page":"e87145","article-title":"Acceleration of diagnosis and treatment initiation using the Elecsys\u00ae HCV Duo assay","volume":"17","author":"Namisaki","year":"2025","journal-title":"Cureus"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"e70286","DOI":"10.1002\/jcla.70286","article-title":"Improving linkage to the HCV care cascade in nonspecialist settings: Evaluation of the performance and triage utility of the Elecsys HCV Duo assay in Japan","volume":"40","author":"Setoyama","year":"2026","journal-title":"J. Clin. Lab. Anal."},{"key":"ref_13","unstructured":"World Health Organization (2022). Updated Recommendations on Simplified Service Delivery and Diagnostics for Hepatitis C Infection: Policy Brief, World Health Organization."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1053\/jhep.2002.34130","article-title":"Clinical utility of total HCV core antigen quantification: A new indirect marker of HCV replication","volume":"36","author":"Patel","year":"2002","journal-title":"Hepatology"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1046\/j.1423-0410.2000.7820080.x","article-title":"Detection of hepatitis C core antigen in the antibody negative \u2018window\u2019 phase of hepatitis C infection","volume":"78","author":"Peterson","year":"2000","journal-title":"Vox Sang."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"e0083224","DOI":"10.1128\/jcm.00832-24","article-title":"Comparison of a dual antibody and antigen HCV immunoassay to standard of care algorithmic testing","volume":"62","author":"Bui","year":"2024","journal-title":"J. Clin. Microbiol."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Kanokudom, S., Poovorawan, K., Nilyanimit, P., Suntronwong, N., Aeemjinda, R., Honsawek, S., and Poovorawan, Y. (2024). Comparison of anti-HCV combined with HCVcAg (Elecsys HCV Duo immunoassay) and anti-HCV rapid test followed by HCV RNA analysis using qRT-PCR to identify active infection for treatment. PLoS ONE, 19.","DOI":"10.1371\/journal.pone.0313771"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"100261","DOI":"10.1016\/j.jcvp.2026.100261","article-title":"Performance evaluation of the Elecsys\u00ae HCV Duo immunoassay for hepatitis C virus through simultaneous antibody and core antigen detection","volume":"6","author":"Sugiura","year":"2026","journal-title":"J. Clin. Virol. Plus"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"192","DOI":"10.7883\/yoken.JJID.2025.032","article-title":"Innovative hepatitis C screening: Clinical utility of the HCV antigen-antibody assay in Japan","volume":"78","author":"Inoue","year":"2025","journal-title":"Jpn. J. Infect. Dis."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"e70095","DOI":"10.1111\/jvh.70095","article-title":"Performance evaluation of the Elecsys HCV Duo immunoassay in the public healthcare setting in Cape Town, South Africa","volume":"32","author":"Hardie","year":"2025","journal-title":"J. Viral Hepat."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"118","DOI":"10.14744\/hf.2025.27743","article-title":"The usefulness of a simultaneous immunoassay for hepatitis C virus antigen-antibody using the ELECSYS HCV Duo assay","volume":"7","author":"Amano","year":"2026","journal-title":"Hepatol. Forum"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"e71050","DOI":"10.1002\/jmv.71050","article-title":"Comprehensive evaluation of the Elecsys HCV Duo immunoassay for active hepatitis C detection: Insights from the DEPCDUO study","volume":"98","author":"Gosset","year":"2026","journal-title":"J. Med. Virol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/j.jcv.2014.05.014","article-title":"Clinical utility of hepatitis C virus core antigen quantification in patients with chronic hepatitis C","volume":"61","author":"Chevaliez","year":"2014","journal-title":"J. Clin. Virol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/j.jviromet.2008.12.009","article-title":"A new sensitive and automated chemiluminescent microparticle immunoassay for quantitative determination of hepatitis C virus core antigen","volume":"157","author":"Morota","year":"2009","journal-title":"J. Virol. Methods"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"345","DOI":"10.7326\/M16-0065","article-title":"Hepatitis C core antigen testing for diagnosis of hepatitis C virus infection: A systematic review and meta-analysis","volume":"165","author":"Freiman","year":"2016","journal-title":"Ann. Intern. Med."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1016\/j.jcv.2009.08.014","article-title":"Performance and clinical utility of a novel fully automated quantitative HCV-core antigen assay","volume":"46","author":"Mederacke","year":"2009","journal-title":"J. Clin. Virol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"e189","DOI":"10.3350\/cmh.2025.1486","article-title":"Diagnostic accuracy of a clinically accessible iTACT-based HCV core antigen assay in a Japanese cohort","volume":"32","author":"Amano","year":"2026","journal-title":"Clin. Mol. Hepatol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1111\/hepr.70037","article-title":"Clinical evaluation of initial experiences with the qualitative dual detection of core antigen and antibodies immunoassay for hepatitis C virus screening test","volume":"56","author":"Om","year":"2026","journal-title":"Hepatol. Res."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"105293","DOI":"10.1016\/j.jcv.2022.105293","article-title":"Multicenter performance evaluation of the Elecsys HCV Duo immunoassay","volume":"156","author":"Majchrzak","year":"2022","journal-title":"J. Clin. Virol."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Ananchuensook, P., Wongpiyabovorn, J., Avihingsanon, A., and Tangkijvanich, P. (2024). Performance of Elecsys HCV Duo immunoassay for diagnosis and assessment of treatment response in HCV patients with or without HIV infection. Diagnostics, 14.","DOI":"10.3390\/diagnostics14192179"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"253","DOI":"10.3343\/alm.2023.0306","article-title":"Performance evaluation of the Roche Cobas 5800 HBV and HCV tests: Comparison of the 200 and 500 \u03bcL protocols","volume":"44","author":"Jeong","year":"2024","journal-title":"Ann. Lab. Med."}],"container-title":["Diagnostics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/19\/3239\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T15:24:11Z","timestamp":1791473051000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2075-4418\/16\/19\/3239"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,7]]},"references-count":31,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2026,10]]}},"alternative-id":["diagnostics16193239"],"URL":"https:\/\/doi.org\/10.3390\/diagnostics16193239","relation":{},"ISSN":["2075-4418"],"issn-type":[{"value":"2075-4418","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,7]]}}}