Elecsys® HBsAg II quant II

Immunoassay for the quantitative determination of hepatitis B surface antigen (HBsAg)

Hepatitis B is a potentially life threatening liver infection caused by the hepatitis B virus (HBV). It is transmitted through contact with the blood or other body fluids of an infected person.¹

The disease is not always self limiting: In adults approx. 5 % of acute infections will follow a chronic course of varying degrees of severity; infants will develop chronic hepatitis B in up to 90 % of the cases.¹

An estimated 257 million people are living with HBV infection. In 2015, hepatitis B resulted in 887,000 deaths, mostly from complications (including cirrhosis and hepatocellular carcinoma).¹ Sustained HBsAg loss with or without seroconversion to anti-HBs is associated with complete immune control of the virus, remission of the activity of chronic hepatitis B (CHB) and an improved long-term outcome.^2-4

Seroclearance of HBsAg is now considered the goal for functional cure of CHB.⁵ As a result, quantification of HBsAg levels is now routinely used to monitor natural disease progression and to predict the response to antiviral treatment in CHB patients receiving peginterferon alfa-2a and nucleos(t)ide analogues, as well as during clinical studies of new HBV therapeutics.^6-7

Elecsys^® HBsAg II quant II

Systems

cobas e 411 analyzer, cobas e 601 module, cobas e 801 module
Testing Time

18 minutes
Test principle

Sandwich assay.
Calibration

2-point
Interpretation

The analyzer automatically calculates the analyte concentration (IU/mL) based on the measurement of Cal1 and Cal2. In case of a manual pre-dilution, the dilution factor needs to be accounted for manual calculation of the final result.
Sample material

Serum collected using standard sampling tubes or tubes containing separating gel. Li‑heparin, Na‑heparin, K2‑EDTA, or Na‑citrate plasma.
Sample volume

50 μL cobas e 411 analyzer, cobas e 601 module
30 μL cobas e 801 module
Onboard stability

8 weeks cobas e 411 analyzer, cobas e 601 module
16 weeks cobas e 801 module
Intermediate precision in positive samples

cobas e 411 analyzer: CV 2.9 – 5.3 %
cobas e 601 module: CV 2.0 – 5.3 %
cobas e 801 module: CV 2.1 – 2.9 %
Measuring range for diluted samples*

cobas e 411 analyzer: 5 – 13,000 IU/mL
cobas e 601 module: 20 – 52,000 IU/mL
cobas e 801 module: 45 – 117,000 IU/mL for 900-fold diluted samples 1,350 – 3,510,000 IU/mL for 27,000-fold diluted samples
cobas e flow

cobas e 411 analyzer: N/A
cobas e 601 module: N/A
cobas e 801 module: Automatic rerun with or without dilution, for convenient use of extended measuring

* Measuring range for undiluted samples: 0.05 – 130 IU/mL for all platforms

References

WHO. Hepatitis B. Fact sheet N°204. Available at: http://www.who.int/mediacentre/factsheets/fs204/en, accessed November 2017.
Lampertico, P. et al. (2017). EASL 2017 Clinical Practice Guidelines on the management of hepatitis B virus infection. J. Hepatol. 67, 370-398.
Sarin, S.K. et al. (2016). Asian-Pacific clinical practice guidelines on the management of hepatitis B: a 2015 update. Hepatol. Int. 10, 1-98.
Terrault, N.A. et al. (2016). AASLD guidelines for treatment of chronic hepatitis B. Hepatology 63, 261-283.
Lok, A.S. et al. (2017). Hepatitis B cure: From discovery to regulatory approval. J. Hepatol. 67, 847-861.
Cornberg, M., et al. (2017). The role of quantitative hepatitis B surface antigen revisited. J. Hepatol. 66, 398-411.
National Institute for Health and Care Excellence. (2013). Hepatitis B (chronic): diagnosis and management of chronic hepatitis B in children, young people and adults. Available from: http://www.nice.org.uk/nicemedia/live/14191/64234/64234.pdf, Accessed November 2017.