Elecsys® HBsAg II quant II RxDx
Empowering chronic hepatitis B management with accurate, automated HBsAg quantification and companion diagnostic precision
Chronic hepatitis B virus (HBV) infection remains a global and national health challenge, affecting an estimated 240 million people worldwide.1-3 Major diagnostic and therapeutic gaps persist across the cascade of care as only 27% of patients are aware of their infection status and less than 5% are on treatment.2 Globally in 2024, approximately 1.1 million people died from HBV-related liver cirrhosis and liver cancer.2 This represents a 17% increase in HBV-related mortality since 2015, translating to approximately 3,500 deaths per day globally.2,3
Standard lifelong nucleos(t)ide analogue (NA) therapies effectively suppress viral replication (HBV DNA), but they rarely eliminate the virus or achieve a "functional cure"—defined as sustained loss of hepatitis B surface antigen (HBsAg) and undetectable HBV DNA for at least 24 weeks after discontinuing all HBV treatment (achieved by only 1% to 4% of patients annually on standard therapy).4,5
Today, chronic hepatitis B management is undergoing a paradigm shift toward finite, targeted therapeutics designed to restore host immune control and achieve a functional cure.4,6 In this context, quantitative determination of HBsAg has emerged as the critical biomarker required to identify eligible patients for treatment, characterize disease phase, stratify clinical risk, define prognosis, guide treatment, and define treatment endpoints.4,6,7
The approval of the Elecsys® HBsAg II quant II RxDx immunoassay in the U.S. marks a historic diagnostic milestone as the first automated quantitative HBsAg assay authorized by the U.S. FDA.8 The FDA granted the assay a De Novo classification as a companion diagnostic (CDx) for use with FDA-approved antiviral therapies. This advancement brings personalized healthcare into chronic viral hepatitis management, providing laboratories with a high-precision method as an aid in the selection and management of patients undergoing antiviral therapy.9
Elecsys® HBsAg II quant II RxDx immunoassay consolidates high-precision electrochemiluminescence (ECLIA) technology onto Roche's industry-leading cobas® e platform family, delivering standardized, actionable results in just 18 minutes with automated onboard dilution. It bridges a long-standing diagnostic void in American liver disease care—equipping clinicians and laboratories with the precision required to guide patients toward functional cure.8
The RxDx test is available at the following testing locations until further notice
Quest Diagnostics
General testing information can be found via this link.
Current customers: Order directly via the Quanum Lab Services Manager portal or search test code (TC) 22772 in your integrated EMR.
Non-customers: Contact the National Customer Service Team at 1-866-MYQUEST (1-866-697-8378) to order or open an account.
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Overview
Product specification |
Value |
Systems |
cobas® e 801 analytical unit/cobas® pro integrated solutions |
Testing time |
18 minutes |
Test principle |
Double-antibody sandwich assay, quantitative |
Calibration |
2-point calibration |
Traceability |
Traceable to the WHO 2nd International Standard for HBsAg (NIBSC code: 00/588; subtype adw2, genotype A) |
Quality control |
Liquid, ready-to-use |
Specimen types |
Human serum (standard tubes and gel separator tubes); lithium heparin, sodium heparin, K₂-EDTA, and sodium citrate plasma |
Sample volume |
30 μL |
Measuring range |
0.14 IU/mL - 3,510,000 IU/mL |
Reagent onboard stability |
≥16 weeks |
Intermediate precision |
2.1% - 4.2% |
Technical documents
References:
World Health Organization. Hepatitis B [Internet; cited 2026, Oct]. Available from: https://www.who.int/news-room/fact-sheets/detail/hepatitis-b.
World Health Organization. Hepatitis [Internet; cited 2026 Oct]. Available from: https://www.who.int/data/gho/data/themes/chronic-viral-hepatitis.
Global hepatitis report 2026. Geneva: World Health Organization; 2026. Licence: CC BY-NC-SA 3.0 IGO. ISBN 978-92-4-012238-3 (electronic version). ISBN 978-92-4-012239-0 (print version).
Ghany MG, Buti M, Lampertico P, Lee HM; 2022 AASLD-EASL HBV-HDV Treatment Endpoints Conference Faculty. Guidance on treatment endpoints and study design for clinical trials aiming to achieve cure in chronic hepatitis B and D: Report from the 2022 AASLD-EASL HBV-HDV Treatment Endpoints Conference. J Hepatol. 2023 Nov;79(5):1254-1269.
Terrault NA, Lok ASF, McMahon BJ, et al. Update on prevention, diagnosis, and treatment of chronic hepatitis B: AASLD 2018 hepatitis B guidance. Hepatology. 2018 Apr;67(4):1560-1599.
European Association for the Study of the Liver (EASL). EASL Clinical Practice Guidelines on the management of hepatitis B virus infection. J Hepatol. 2025;83(2):502–583. DOI: 10.1016/j.jhep.2025.04.015.
Conners EE, Panagiotakopoulos L, Hofmeister MG, et al. Screening and Testing for Hepatitis B Virus Infection: CDC Recommendations - United States, 2023. MMWR Recomm Rep. 2023 Mar 10;72(1):1-25.
Food and Drug Administration (FDA). FDA News Release. FDA Approves First-of-Its-Kind Chronic Hepatitis B Treatment [Internet; cited 2026 Oct]. Available from: https://www.fda.gov/news-events/press-announcements/fda-approves-first-its-kind-chronic-hepatitis-b-treatment.
F. Hoffmann-La Roche Ltd. Elecsys® HBsAg II quant II RxDx Method Sheet. (v1.0). 2026.
Hou J, Lim SG, Buti M, et al. Phase 3 Results of Bepirovirsen Treatment for Chronic Hepatitis B Virus Infection. N Engl J Med. 2026 Jun 25;394(24):2395-2406.