EBV VCA and EBNA IgG Combo Rapid Test Cassette

Sample

whole blood, serum or plasma

Intended Use

The EBV VCA and EBNA IgG Combo Rapid Test Cassette (Whole Blood/Serum/Plasma) is a rapid chromatographic immunoassay for the qualitative detection of IgG antibodies against VCA and EBNA of Epstein-Barr virus in human whole blood, serum, or plasma.

Storage

The kit can be stored at room temperature or refrigerated (2-30°C). The test cassette is stable through the expiration date printed on the sealed pouch. The test cassette must remain in the sealed pouch until use. DO NOT FREEZE. Do not use beyond the expiration date.

Performance Characteristics

Sensitivity and Specificity
The EBV VCA and EBNA IgG Combo Rapid Test Cassette (Whole Blood/Serum/Plasma) has been compared with a leading commercial EBV ELISA test using clinical specimens. The results show that the relative sensitivity of the EBV VCA IgG Rapid Test (Whole Blood/Serum/Plasma) is 95.6% and the relative specificity is 96.5%, the relative sensitivity of the EBNA IgG Rapid Test (Whole Blood/Serum/Plasma) is 96.2% and the relative specificity is 97.8%.

Relative sensitivity: 95.6% (95%CI*: 90.1%~98.6%)
Relative specificity: 96.5% (95%CI*: 92.1%~98.9%)
Accuracy: 96.1% (95%CI*: 93.0%~98.1%)

Relative sensitivity: 96.2% (95%CI*: 90.6%~99.0%)
Relative specificity: 97.8% (95%CI*: 93.7%~99.5%)
Accuracy: 97.1% (95%CI*: 94.1%~98.8%)

Precision

Intra-Assay
Within-run precision has been determined by using 5 replicates of seven specimens: negative, VCA IgG low positive, VCA IgG middle positive, VCA IgG high positive, EBNA IgG low positive, EBNA IgG middle positive and EBNA IgG high positive. The specimens were correctly identified >99% of the time.
Inter-Assay
Between-run precision has been determined by 5 independent assays on the same seven specimens: negative, VCA IgG low positive, VCA IgG middle positive, VCA IgG high positive, EBNA IgG low positive, EBNA IgG middle positive and EBNA IgG high positive. Three different lots of the EBV VCA and EBNA IgG Combo Rapid Test Cassette (Whole Blood/Serum/Plasma) have been tested using these specimens. The specimens were correctly identified >99% of the time.

General Description

Epstein-Barr Virus (EBV) is a ubiquitous human virus which causes infectious mononucleosis (IM), a self-limiting lymphoproliferative disease. By adulthood virtually everyone has been infected with and has developed immunity to the virus. In underdeveloped countries, seroconversion to the virus takes place in early childhood and is usually asymptomatic.
In more affluent countries, primary EBV infections are often delayed until adolescence or later, and manifest as IM in about 50% of this age group. Following seroconversion, whether symptomatic or not, EBV establishes a chronic, latent infection in B lymphocytes which probably lasts for life. EBV replicates in oropharyngeal epithelial cells and is present in the saliva of most patients with IM. In addition, 10-20% of healthy persons who are EBV antibody positive shed the virus in their oral secretions. Reactivation of the latent viral carrier state, as evidenced by increased rates of virus shedding, is enhanced by immunosuppression, pregnancy, malnutrition, or disease. Chronic EBV infections, whether latent or active, are rarely associated with disease. However, EBV has been implicated at least as a contributing factor in the etiology of nasopharyngeal carcinoma, Burkitt' s lymphoma, and lymphomas in immunodeficient patients.
The Paul-Bunnell-Davidsohn test for heterophile antibody is highly specific for IM. However, 10-15% of adults and higher percentages of children and infants with primary EBV infections do not develop heterophile antibodies. There is a need for EBV-specific serological tests to differentiate primary EBV infections that are heterophile negative, from mononucleosis-like illnesses caused by other agents such as cytomegalovirus, adenovirus, and Toxoplasma gondii. Antibody titers to specific EBV antigens correlate with different stages of IM. Both IgM and IgG antibodies to the viral capsid antigen (VCA) peak three to four weeks after primary EBV infection. IgM anti-VCA antibodies decline rapidly and are usually undetectable after 12 weeks. IgG anti-VCA antibody titers decline slowly after peaking but last indefinitely. Antibodies to EBV nuclear antigen (EBNA) develop from one month to six months after infection and, like anti-VCA antibodies, persist indefinitely. Antibodies to EBNA indicate that the infection was not recent.
EBV early antigens (EA) consist of two components; diffuse (D), and restricted (R). The terms D and R reflect the different patterns of immunofluorescent staining exhibited by the two components. Antibodies to EA appear transiently for up to three months during the acute phase of IM in 85% of patients. The antibody response to EA in IM patients is usually to the D component, whereas silent seroconversion to EBV in children produces antibodies to the R component. A definitive diagnosis of primary EBV infection can be made with 95% of acute phase sera based on the detection of antibodies to VCA, EBNA, and EA.
The EBV VCA and EBNA IgG Combo Rapid Test Cassette (Whole Blood/Serum/Plasma) is a rapid test that utilizes a combination of EBV VCA antigen or EBNA antigen coated colored particles for the detection of IgG antibodies to VCA or EBNA of Epstein-Barr virus in human whole blood, serum, or plasma.