title: Reliability of the Siemens Enzygnost and Novagnost Epstein-Barr virus assays for routine laboratory diagnosis: agreement with clinical diagnosis and comparison with the Merifluor Epstein-Barr virus immunofluorescence assay.
abstract: BACKGROUND
  Diagnosis of Epstein-Barr virus (EBV) infection is routinely conducted by clinical laboratories, especially to diagnose infectious mononucleosis. At an estimated general population incidence of 1:200, this represents a potentially significant testing burden. We evaluated the reliability of the Siemens Novagnost® and Enzygnost® EBV microtiter assays measuring VCA IgM and IgG, and EBNA-1 IgG for clinical diagnosis of EBV-related infectious mononucleosis.
  
  
  METHODS
  Remnant sera from 537 patients tested for EBV infection were used to compare the Siemens assays to each other and to the Merifluor assay. The Siemens assays are qualitative/semiquantitative, automatable enzyme immunoassays. The Merifluor assays are manual, qualitative indirect immunofluorescent assays. Testing was conducted on the Siemens and Merifluor assays in parallel. All assays were conducted and interpreted according to each manufacturer's specifications. Agreement of serostatus between each of the three assays was assessed. Discrepant results were resolved using a third method (Mikrogen recomLine).
  
  
  RESULTS
  Final EBV serostatus indicated 2.9% of the population had an acute infection, 89.6% had a past infection, and 7.5% were EBV naive. All three assays demonstrated 100% agreement with acute infection. Agreement with past-infection serostatus was 99.1% for Enzygnost, between 86% and 98.8% for Novagnost, and 98.1% for Merifluor. Seronegative agreement was 100% for Enzygnost, 89.7% for Novagnost, and 92.3% for Merifluor.
  
  
  CONCLUSIONS
  The Siemens Enzygnost and Novagnost EBV microtiter assays are suitable for clinical rule-in of acute EBV infection and for identifying EBV-naive individuals. Both assays also adequately identify remote EBV infections. Because these assays can be automated, they can improve speed and efficiency of EBV testing, especially in high-volume laboratories.
authors.affiliation: University of Graz, Institute for Hygiene, Universitätsplatz 4, Graz 8010, Austria.
authors.forename: Christina
authors.initials: C
authors.lastname: Kreuzer
authors.forename: Klaus Udo
authors.initials: KU
authors.lastname: Nabeck
authors.forename: H Roma
authors.initials: HR
authors.lastname: Levy
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Daghofer
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D020031:Epstein-Barr Virus Infections / Q000175:diagnosis* / Q000276:immunology; D005455:Fluorescent Antibody Technique / Q000295:instrumentation / Q000379:methods* / Q000592:standards*; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000295:instrumentation / Q000379:methods* / Q000592:standards*; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D015203:Reproducibility of Results; D012698:Serologic Tests
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M