Epstein-Barr Virus (EBV) IgM EIA

For the qualification detection of human IgM antibodies to Epstein-Barr (EBV) viral capsid antigen (VCA) in human serum by enzyme immunoassay, as an aid in differentiating active or recent Epstein-Barr virus infection from past infection. These reagents have not received FDA clearance for use in testing blood or plasma donors.

About Epstein-Barr Virus

This summary does not intend to imply additional performance claims other than those already indicated in the Clinical Utility section.

Epstein-Barr virus (EBV) is the etiological agent of infectious mononucleosis (IM), and has also been implicated in Burkitt's lymphoma and nasopharyngeal carcinoma.¹ The designation of infectious mononucleosis classically refers to an Epstein-Barr virus-induced illness in young adults characterized by reactive blood smears, exudative pharyngitis, prominent cervical lymphadenopathy, and serologically detectable heterophile antibodies. These clinical manifestations can also be caused by a number of other pathogenic agents including cytomegalovirus, Toxoplasma gondii, rubella virus, hepatitis virus, human immunodeficiency virus (HIV), and uncommonly by drugs such as Halothane, Hydantoin, Dapasone, and Azulfidine.^2-4

Diagnosis of acute EBV IM is generally confirmed by a positive heterophile antibody test. The severity of the disease, however, is not indicated by the relative titer of heterophile antibodies.⁵ In addition, difficulties in diagnosis arise when the heterophile antibody test is negative, or when the clinical manifestations are atypical or unusually severe.

IgG antibodies to VCA may be present early during EBV infection, but they persist indefinitely after the occurrence of clinical disease and may merely indicate EBV infection at some time in the past. IgM antibodies to VCA, on the other hand, are present in the circulation 1 to 6 weeks after the onset of EBV illness and usually disappear in 3 to 6 months. Thus the presence of VCA IgM usually suffices for the diagnosis of acute IM. Further verification may be obtained by testing for the presence of antibodies directed against the other EBV-specific antigens, early antigen and EBNA. Heterophile antibody negative sera demonstrating VCA IgM and transient levels of antibody to early antigen and considered diagnostic for acute IM. In contrast, antibodies to EBNA appear late during IM infections, and IgG antibodies to EBNA may persist for years, even for life, and are indicative of the convalescent phase of IM infection.

The EB VCA IgM EIA test is an ELISA test which utilizes a microwell format. Test results are obtained after one and one-half hours incubation time. They are objective and normalized as Index values, permitting uniformity of reporting.

Diluted samples are incubated in VCA antigen-coated wells. Absorbents have been included in the Diluent to neutralize the effects of rheumatoid factor and IgG antibody. VCA IgM antibodies (if present) are immobilized in the walls. Residual sample is eliminated by washing and draining, and conjugate (enzyme labeled antibodies to human IgM) is added and incubated. If IgM antibodies to VCA are present, the conjugate will be immobilized in the wells. Residual conjugate is eliminated by washing and draining, and the substrate is added and incubated. In the presence of the enzyme, the substrate is converted to a yellow and product which is read photometrically.

Test performed by Eurofins DPT, 6933 S. Revere Parkway, Centennial, CO 80112. This test has not been cleared or approved for diagnostic use by the U.S. Food and Drug Administration. See package insert for more information.