EBV VCA IgM ELISA Kit

Sample

Serum or plasma.

Intended Use

The Epstein-Barr Virus VCA IgM is a qualitative and quantitativeimmunoassay for the detection of viral capsid antigen-specific human IgM antibodies in serum or plasma. The test supports the diagnosis of an acute or recent infectious event. The test system can be processed manually or automatically. The tests are designed for professional use.

Contents of Kit

1. Break apart microtiter test strips each with eight antigen coated single wells (altogether 96) MTP 1 frame
The coating material is inactivated.
2. Standard serum (ready-to-use) STD 2 x 2 ml
Human serum in protein containing phosphate buffer; negative for anti-HIV Ab,
HBs-Ag (Hepatitis B-Virus surface antigen) and anti-HCV Ab;
preservative: < 0.1 % sodium azide; colouring: Amaranth O
3. Negative control serum (ready-to-use) NEG 2 ml
Human serum in protein containing phosphate buffer; negative for anti-HIV Ab,
HBs-Ag (Hepatitis B-Virus surface antigen) and anti-HCV Ab;
preservative: < 0.1 % sodium azide; colouring: Lissamin Green V
4. Anti-human IgM conjugate (ready-to-use) APC 13 ml
depending on the immunoglobulin class of the test kit, the appropriate conjugate is provided;
Anti-human IgM polyclonal antibody, conjugated to alkaline phosphatase, stabilised with protein stabilisation solution;
preservative: < 0.1 % methylisothiazolone, < 0.1 % bromnitrodioxane
5. Washing solution concentrate (sufficient for 1000 ml) WASH 33.3 ml
Sodium chloride solution with Tween 20 and 30 mM Tris/HCl, pH 7.4;
preservative: < 0.1 % sodium azide
6. Dilution buffer (ready-to-use) DILB 2 x 50 ml
Protein containing phosphate buffer with Tween 20 ( DILB );
preservative: < 0.1 % sodium azide; colouring: 0.01 g/l Bromphenol blue
7. Stopping solution (ready-to-use) STOP 15 ml
< 0.1 N sodium hydroxide, 40 mM EDTA
8. Substrate (ready-to-use) pNPP 13 ml
Para-nitrophenylphosphate in solvent free buffer;
preservative: < 0.1 % sodium azide

Storage

Unopened at 2 – 8 °C, after opening at 2 – 8 °C.

Detection Range

Measurement Range: 4 – 200 U/ml
Limit of Quantification: 4 U/ml
Borderline Region: 9 – 13 U/ml
The borderline ranges of the Epstein-Barr Virus VCA IgM tests are specified on the quality control certificates and indicate the range of borderline test results. Values below this range indicate a negative test result; values above the borderline range are interpreted positive.

Detection Limit

The limits of quantification are specified on the quality control certificate of the Epstein-Barr Virus VCA IgM. The linearity of dilution within this range has been demonstrated in comprehensive evaluation studies. In case a patient sample shows a test result above the upper limit of quantification, the sample may be tested at a higher dilution. The resulting antibody activity must then be multiplied by the additional dilution factor.

Sensitivity

> 99 %

General Description

The Epstein-Barr virus (EBV) is a human pathogenic virus belonging to the Herpesvirus family. It occurs worldwide and, in common with all Herpesviruses, the prevalence in the general population is high, reaching 90 to 95 % in the adult population. In the so called developing countries, primary infection is generally in the first year of life and is often asymptomatic. In contrast, in countries with high standards of hygiene primary infection occurs mainly in teenagers and young adults. The peak age for infection is between 15 and 20 years and around 50 % of those infected will develop an infectious mononucleosis.
Transmission is primarily through exchange of saliva although other routes are possible such as from blood products or bone marrow transplantation.

During a primary infection the salivary glands are initially involved and virus reaches the nose and throat via the saliva. At this stage, the symptoms of infection are flu-like. The virus is disseminated throughout the body by infected B lymphocytes, which are usually regulated by the immune system but are stimulated to proliferate by the virus. These infected B lymphocytes in the peripheral blood are characteristically atypical with a variable shape, distinct basophile cytoplasm and an obvious nucleus. As the disease progresses it may manifest as high fever, splenomegaly, lymphadenitis, thrombocytopenia, and hepatitis. Due to the virus's dissemination and transmission strategy, primarily via saliva, infectious mononucleosis (IM) or glandular fever has also been called the "kissing disease". In rare cases an acute IM infection can lead to a chronic active disease state. In such cases the symptoms of IM may continue for a considerable time period. The pathogenesis of this complication is unclear although genetic predisposition and/or infection with a particularly lytic strain of virus are suspected.

In certain geographical regions EBV is closely associated with the incidence of nasopharyngeal carcinoma. This carcinoma of the pharynx, nose and throat consists of undifferentiated epithelial cells and has a propensity for metastasis. This disease occurs globally but is particularly common in certain regions of south China. Genetic predisposition as well as environmental aspects such as diet are under discussion as cofactors. Burkitt´s lymphoma (BL) is also a tumor associated with EBV, primarily in the geographical regions of Africa and Papua New Guinea. This monoclonal B-cell tumor is also linked to areas with high incidence of malaria and over 90 % of such tumors show evidence of EBV.
The influence of plasmodium infection on the immune response brings the role of malaria as a cofactor for BL into discussion. Sporadic cases of BL in other regions do occur, however in such cases EBV is much less commonly detected and other cofactors such as genetic changes through chromosome translocation are thought to be responsible for the tumor.
Very early in infection IgM is produced against the early antigen (EA). Maximum concentrations of antibodies tend to coincide with the onset of symptoms, and approximately two weeks after initial infection EA IgG, VCA (Virus Capsid Antigen) IgM and VCA IgG production begins. The highest anti-VCA IgM concentrations are found around three weeks following the onset of symptoms. EA IgG antibodies are often detectable for a considerable time following infection. Subsequently the concentrations of VCA IgM and later EA IgG antibodies fall. Anti-VCA IgG antibodies reach a peak some six weeks after symptoms appear and remain at a high level lifelong. Around three weeks after appearance of symptoms EBNA1 IgG antibodies, which are an indicator of a past infection, begin to be produced and reach a peak at around seven months and remain at a high level for life following a normal EBV infection. Reactivation of the virus (such as immunosuppression)
usually leads to a significant increase in EA IgG antibodies while VCA IgM titres rarely increase. Only in rare cases a loss of EBNA1 IgG antibodies can occur after immunosuppression.