Elecsys® Anti-HAV IgM

Immunoassay for the qualitative determination of IgM antibodies against 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 documented1-5

Hepatitis A occurs sporadically and in epidemics worldwide, with around 1.4 million new HAV infections reported each year3,4. 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 handlers1,4-6.

 

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 infection3,7-11

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)
Algorithm 1

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
Algorithm 2

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 infection3,7-10,12

Elecsys® Anti-HAV IgM

References

 

  1. Lemon, S.M., Ott, J.J., Van Damme, P.V., Shouval, D. (2017). Type A viral hepatitis: A summary and update on the molecular virology, epidemiology, pathogenesis and prevention. J Hepatol 68(1), 167-84
  2. Lemon, S.M. (1985). Type A viral hepatitis. New developments in an old disease. N Engl J Med 313, 1059-1067.
  3. European Centre for Disease Prevention and Control (ECDC). Hepatitis A virus in the EU/EEA, 1975–2014. ECDC technical report. Stockholm: ECDC. 2016. Available from: http://ecdc.europa.eu/en/publications/Publications/hepatitis-a-virus-EUEEA-1975-2014.pdf
  4. Fiore, A.E. (2004). Hepatitis A transmitted by food. Clin Infect Dis 38(5), 705-15.
  5. Lemon, S.M. and Binn, L.N. (1983). Serum neutralizing antibody response to hepatitis A virus. J Infect Dis 148(6),1033-39.
  6. Lemon, S.M., Brown, C.D., Brooks, D.S., Simms, T.E., Bancroft, W.H. (1980). Specific immunoglobulin M response to hepatitis A virus determined by solidphase radioimmunoassay. Infect Immun 28, 927-936.
  7. Cuthbert, J.A. (2001). Hepatitis A: Old and New. Clin. Microbiol. Rev. 14(1), 38-58.
  8. Stapleton, J.T. (1995). Host immune response to hepatitis A virus. J Infect Dis 171, 9-14.
  9. Sjogren, M.H., Hoke, C.H., Binn, L.N., Eckels, K.H., Dubois, D.R., Lyde, L. et al. (1991). Immunogenicity of an inactivated hepatitis A vaccine. Ann Intern Med 114, 470-1.

Elecsys® Anti-HAV IgM

  • Systems

    cobas e 411 analyzer, cobas e 601 / cobas e 602 modules, cobas e 801 module

  • 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 801 module: 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 801 module

  • Onboard stability

    8 weeks cobas e 411 analyzer, cobas e 601 / cobas e 602 modules
    16 weeks cobas e 801 module

  • 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 801 module: 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)