Elecsys^® Anti-HAV IgM

Immunoassay for the qualitative determination of IgM antibodies against hepatitis A virus (HAV)

Elecsys® Anti-HAV IgM

Immunoassay for the qualitative detection of IgM antibodies against HAV

Elecsys^® Anti-HAV IgM is an immunoassay for the in vitro qualitative determination of IgM antibodies to HAV in human serum and plasma. The assay is used as an aid to detect an acute or recently acquired HAV infection¹².

Hepatitis A

Hepatitis A is an acute, inflammatory liver disease caused by infection with the hepatitis A virus (HAV). HAV is a non-enveloped RNA virus in the family of picornaviruses. Of the 7 known genotypes, 4 can infect humans. Only one serotype of HAV has been documented^1-5.

Hepatitis A occurs sporadically and in epidemics worldwide, with around 1.4 million new HAV infections reported each year^3,4. HAV is transmitted fecal-orally either by person-to-person contact or ingestion of contaminated food or water in regions of low hygienic standards. Cooked foods can transmit HAV if the temperature during food preparation is inadequate to inactivate the virus or if food is contaminated through infected food handlers^1,4-6.

HAV has only been linked with acute hepatitis, and most patients fully recover within two months after infection. Only 10 – 15 % of people infected will have prolonged or relapsed illness for up to 6 months. Anti-HAV IgM becomes detectable 5 – 10 days before onset of symptoms, peaks during the symptomatic period and becomes undetectable in 75 % of patients 3 – 6 months after infection, although anti-HAV IgM can also be detected in some patients for a longer period of time. Anti-HAV IgM antibodies develop only very rarely after vaccination. Assays to detect anti-HAV IgM antibodies are used in the differential diagnosis of acute hepatitis to determine a hepatitis A infection^3,7-11.

Proposed algorithms for diagnosis of HAV infection

Unkown HAV immune status

The patient may have an acute or past HAV infection, or may not be immune
Initial test – anti-HAV (total assay)

With this algorithm, all three possible outcomes can be identified by testing first with the anti-HAV (total) assay followed by the anti-HAV IgM assay if necessary. By contrast, an HAV IgG assay alone cannot identify or exclude acute infection; an HAV IgM test is also required.^10,13

Suspected acute HAV infection

The patient is exhibiting clinical symptoms
Initial test – anti-HAV IgM assay

With this algorithm, all three possible outcomes can be clearly identified by testing first with the anti-HAV IgM assay followed by the anti-HAV (total) assay if necessary.^10,13,14

Marker profile

Hepatitis A infection marker profile after natural infection^3,7-10,12

* ALT = alanine aminotransferase

Hepatitis A infection: marker profile after natural infection3,7-10,12

* ALT = alanine aminotransferase

Elecsys^® Anti-HAV IgM

Systems

cobas e 411 analyzer, cobas e 601 / cobas e 602 modules, cobas e 402 / cobas e 801 analytical units
Testing Time

18 minutes
Test principle

μ-capture assay
Calibration

2-point
Interpretation

COI <1.0 = non-reactive
COI ≥1.0 = reactive
Traceability

Roche reference standard
Sample material

cobas e 411 analyzer, cobas e 601 / cobas e 602 modules: Serum collected using standard sampling tubes or tubes containing separating gel. Li-heparin, Na-heparin, K3-EDTA and Na-citrate plasma.

cobas e 402 / cobas e 801 analytical units: Serum collected using standard sampling tubes or tubes containing separating gel. Li-heparin, Na-heparin, K2-EDTA, K3-EDTA and Na-citrate plasma.
Sample volume

10 μL cobas e 411 analyzer, cobas e 601 / cobas e 602 modules
6 μL cobas e 402 / cobas e 801 analytical units
Onboard stability

8 weeks cobas e 411 analyzer, cobas e 601 / cobas e 602 modules
16 weeks cobas e 402 / cobas e 801 analytical units
Intermediate precision in positive samples

cobas e 411 analyzer: CV 2.7 – 5.4 %
cobas e 601 / cobas e 602 modules: CV 5.0 – 7.9 %
cobas e 402 / cobas e 801 analytical units: CV 2.2 – 5.3 %
Clinical sensitivity

100 % (n = 211)
Clinical specificity

100 % (n = 1,312)
Relative sensitivity

Clinically characterized patients with acute HAV infection (N=211): 100 % (98.27 – 100 %*)
Relative specificity

Blood donors (N=1,032): 100 % (99.64 – 100 %)

Hospitalized patients, pregnant women, dialysis patients and drug addicts (N=280): 100 % (98.69 – 100 %)

* 95 % confidence interval (2-sided)

References

Cuthbert, J.A. (2001). Hepatitis A: old and new. Clin Microbiol Rev 14(1), 38-58.
Lemon, S.M. et al. (2018). Type A viral hepatitis: A summary and update on the molecular virology, epidemiology, pathogenesis and prevention. J Hepatol 68, 167-184.
Pischke, S., Wedemeyer, H. (2018). Hepatitis A In: Mauss, S. et al. Hepatology. A Clinical Textbook. Ninth Edition. Available from: https://www.hepatologytextbook.com/. [Accessed: May 11, 2020].
World Health Organization (WHO) (2019). Hepatitis A Factsheet. Available from: https://www.who.int/news-room/fact-sheets/detail/hepatitis-a.
Yong, H.T., Son, R. (2009). Hepatitis A virus - a general overview. Int Food Res J 16, 455-467.
Centers for Disease Control and Prevention (CDC) (2016). Hepatitis A – Questions and Answers for Health Professionals. Available from: https://www.cdc.gov/hepatitis/hav/havfaq.htm [Accessed: May 06, 2020].
Hollinger, F.B., Emerson, S.U. (2007). Hepatitis A virus. In: Fields Virology, Knipe OM, Howley PM (eds), 5th edition, Lippincott Williams and Wilkins, Philadelphia, USA Chapter 27, pp. 911-947.
Stapleton, J.T. (1995). Host Immune Response to Hepatitis A Virus. J Inf Dis 171(suppl 1), 89-14.
Roque-Afonso, A.M. et al. (2010). Hepatitis A virus: serology and molecular diagnostics. Future Virol 5(2), 233-242.
Salete de Paula,V. (2012). Laboratory diagnosis of hepatitis A. Future Virol 7(5), 461-472.
Sjogren, M.H. et al. (1991). Immunogenicity of an inactivated hepatitis A vaccine. Ann Intern Med 114, 470-1.
Elecsys® Anti-HAV IgM method sheet, V17.0 2022-06.
Centers for Disease Control and Prevention. Viral Hepatitis Serology Training, Hepatitis A (2015). Available at: https://www.cdc.gov/hepatitis/resources/professionals/training/serology/training.htm. [Accessed: May 06, 2020].
Gilson, R. and Brook, M.G. (2006). Hepatitis A, B, and C. Sex Transm Infect. 82(Suppl 4), iv35-iv39.
UK Standards for Microbiology Investigations. (2019). Hepatitis A Virus Acute Infection Serology. Issued by the Standards Unit, Microbiology Services, PHE Virology 27(4). Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/772178/V_27i4.pdf [Accessed: June 02, 2020].