Description

The Diagnostic Automation Epstein Barr Virus Nuclear Antigen-1 (EBNA-1) IgG ELISA kit, is intended for the detection of IgG antibody to Epstein Barr Virus Nuclear Antigen-1 in human sera and plasma.

Purified EBNA-1 antigen is coated on the surface of microwells. Diluted patient serum is added to wells, the anti-EBNA specific antibody, if present, will bind to the antigen. All unbound materials are washed away. After adding enzyme conjugate, it binds to the antibody-antigen complex. Excess enzyme conjugate is washed off, and TMB Chromogenic substrate is added. The enzyme conjugate catalytic reaction is stopped at a specific time. The intensity of the color generated is proportional to the amount of specific antibody in the sample. The results are read by a microwell reader compared in a parallel manner with calibrator and controls.

Detection of the Epstein-Barr virus was first described in 1964 by Epstein, Achong, and Barr using electron microscopic studies of cultured lymphoblasts derived from patients with Burkitt’s lymphoma. EBV is classified as a member of the herpes-virus family based upon its characteristic morphology.

EBV infection may demonstrate a wide spectrum of clinical symptoms. The majority of primary EBV infections is transmitted via saliva, occurs during childhood, and is subclinical4. In the U.S., 50% of the population demonstrate EBV antibodies before the age of 5 years; 80% by adulthood. Transfusion-associated EBV infections have also been reported3. In young adults, EBV infection may be clinically manifested as Infectious Mononucleosis (IM) with typical symptoms of sore throat, fever, and lymphadenopathy. College students and military personnel are often cited as a high morbidity incidence population for IM.

Infection of the target cells leads to two forms of viral cycles: 1) latent, nonproductive and 2) productive, replicative infections. In both cycles, one of the earliest antigens expressed is lymphocyte-detected membrane antigen, a cell surface antigen recognized by T-cells. It has been well established that most individuals exposed to EBV develop a heterophile antibody response. Expression of EBNA-1 either follows or parallels membrane antigen at 12 to 24 hours post infection. EBNA-1 is found as nonstructural, intranuclear antigen(s), present in all EBV-transformed cell lines as in tumors from Burkitt’s and nasopharyngeal carcinoma patients. In the fully productive, replicative cycle, the synthesis of antigen follows EBNA-1. The viral capsid antigen complex (VCA) appears late in the replicative cycle.

It has recently become apparent that EBNA-1 is probably not a single antigenic moiety, but a multicomponent antigen complex, on the basis of reactivities of sera from different classes of patients. The major component EBNA-1 has been purified and sequenced in its entirety. Antibody levels of EBNA-1 IgG, are diagnostic in determining acute and convalescent stages in IM IgG antibodies to EBNA-1 are rarely present in acute IM and rise during convalescence. They will rise to a plateau level in three months to a year and will normally persist for life.