The study, reported in BMC Infectious Diseases , evaluated a single assay that detects both HCV antibody and antigen against a comparator workflow using separate antibody and antigen tests. Researchers collected serum samples from people with confirmed HCV infection and people considered at high risk of infection at three Chinese hospitals. They also gathered clinical and demographic information, including comorbidities, sample-collection dates and HCV RNA results, from medical records.

The antibody and antigen modules of HCV Duo were assessed against both the two-assay algorithm and the individual comparator assays using clinical specimens and seroconversion panels. The design therefore measured laboratory agreement and detection timing rather than clinical outcomes associated with use of the assay. Performance was particularly strong among 215 Anti-HCV-reactive samples with available HCV RNA results.

HCV Duo showed 100% agreement with Anti-HCV II in the RNA-positive subgroup, with all 132 samples classified concordantly. In the RNA-negative subgroup, 82 of 83 samples agreed, corresponding to 98.8% agreement. These results demonstrate close correspondence between the antibody component of HCV Duo and the antibody comparator in the analyzed specimens.

The study also reported that HCV Duo maintained consistent detection performance in samples from people with other viral infections, immunocompromised states or interfering factors, although the supplied abstract did not specify the size or numerical performance estimate for every such subgroup. The antigen module showed similar sensitivity to ARCHITECT HCV Ag among samples that were antibody-positive and RNA-positive: HCV Duo detected antigen in 55.3%, compared with 56.8% for ARCHITECT HCV Ag. Its detection sensitivity increased as HCV RNA levels rose.

Concurrent antibody and antigen positivity identified active infection in 34% of antibody-positive cases in the study’s analysis, providing the basis for assessing the assay’s utility in triage. The investigators framed this capability as potentially useful for early HCV screening or triage, while explicitly preserving the requirement for RNA testing when active infection needs reliable confirmation. Timing results in the seroconversion panels provided a separate assessment of diagnostic windows.

Following the first detection of HCV RNA, the mean delay to a positive HCV Duo result was 1.58 days, compared with 28.67 days for antibody testing. ARCHITECT HCV Ag detected antigen slightly earlier than HCV Duo, with a mean delay of 0.42 days after RNA detection. Both antigen assays therefore shortened the interval to detection relative to antibody testing, while the measurements also showed that the two antigen assays did not become positive at precisely the same time.

Overall, the evaluation found good agreement between HCV Duo and the comparator workflow, high concordance with Anti-HCV II among antibody-reactive samples with known RNA status, and earlier antigen detection in seroconversion panels. These findings support the assay’s potential value in early screening or triage, but the study did not establish that HCV Duo could replace molecular testing or independently confirm active HCV infection.

Subject of Research: Clinical evaluation of the Elecsys HCV Duo antibody-and-antigen immunoassay for active HCV infection triage

Article Title: Multicenter evaluation of the Elecsys® HCV Duo assay performance, diagnostic agreement, and utility in active HCV infection triage

Article References: Deng, L., Liu, Y., Luo, X., Feng, X., Lou, J., Cheng, L., Wang, Y., & Liu, X. (2026). Multicenter evaluation of the Elecsys® HCV Duo assay performance, diagnostic agreement, and utility in active HCV infection triage. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14340-0

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14340-0

Keywords: hepatitis C, HCV, Elecsys HCV Duo, immunoassay, HCV antibody, HCV antigen, HCV RNA, diagnostic window, clinical diagnostics, multicenter study, Multicenter, evaluation