Millenium Health Tips

Recently ELISA methods are applied to the diagnosis of EBV infection. The methods using cellular extracts from cells transformed by the virus do not apply to this virus since they are highly nonspecific.

Alternatively we have used both purified proteins, synthetic peptides and recombinant proteins. GP125 has been used purified from P3HR1 line with which it has obtained 95% sensitivity and specificity of 100%.

In regard to the use of synthetic peptides, was applied to p62, whose sequence corresponds to a region of EBNA1, to develop a test to differentiate IgM and IgG responses.
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The IFAC method for anti-EBNA is applied to heat-inactivated samples (56 º C, 30 min). A critical aspect in the determination of antibodies to EBNA is that the wells should not be dry between incubations, as you can get false negative results.

With these techniques in the course of primary infection occurring anti-VCA responses, both IgM and IgG isotype, in a virtually simultaneous. In most cases reach the peak in the time symptoms appear, or a few days later, so in most cases it is possible to detect IgG seroconversion. Between 2 and 3 months after onset of illness, the IgM response falls to undetectable levels, while IgG remains at good levels throughout the life of the individual. (more…)

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Specific serological response

EBV has a complex antigen. Are three classes of antigenic systems: the latent phase antigens, antigens early replicative and late antigens. Not all are important for diagnosis. Among the former, there are the EBV nuclear antigens (EBNA1 and 2). Despite being the first to receive the antibody response to EBNA-1, which occurs in all infected individuals, is a late marker of infection. Among the early antigens (EA) and depending on your location there are two types: diffuse (EA-D in the nucleus and cytoplasm) and restricted (EA-R, only in cytoplasm).

The response of anti-EA is not universal and indicates that the cell has entered a lytic cycle and producer. Finally, among the late ones, the antigen of the virus capsid (VCA) is expressed equally abundantly in the lytic and productive infection, and induces a response of the IgM isotype in the primary disease that lasts 2-3 months, and IgG isotype , which remains detectable for life.  (more…)

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In general, the best procedure for laboratory diagnosis of viral infections is isolation of the virus or any of its components or products. While acknowledging cell types naturally susceptible to infection by EBV in vitro is reduced to B cells, which are processed in a technologically complex and slow process, so that isolation is an imp procedure for most laboratories diagnostics.

The identification of either virus antigens has proved an adequate approximation. Finally, the detection of HBV DNA by the chain reaction of polymerase has shown a good performance comparative serological studies for the diagnosis of mononucleosis in the acute phase. (more…)

Infectious mononucleosis is the most typical clinical form of primary infection by EBV. As with the other HV infection in children is much milder than that occurring in adolescents or adults.

The incubation period of about a month. After a prodromal period, characterized by chills, sweating, fever and malaise, the disease occurs, which in its most typical form includes the triad of sore throat, fever and lymphadenopathy.

They also appear frequently hepatosplenomegaly and rash. Most cases remits spontaneously within 3 to 4 weeks, although fatigue can last a little longer.

There are some important neurological complications (meningoencephalitis and Guillain Barre syndrome), laryngeal obstruction or rupture of the spleen. In most cases the recovery is complete by symptomatic treatment. (more…)

Immunocompetent individuals remain EBV in B lymphocytes as a latent chronic infection which helps them survive and spread to new host cells. This long coexistence is possible because the virus develops different mechanisms to evade the immune system. During the acute phase the virus expresses gene products of about 90 while in the latent phase antigens are expressed only EBNA and LPM2 (EBNA 1,2,3 A, 3B, 3C and the LPM associated with cell transformation 2b Ay 1.2 ).

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EBNA1 is required for that automantenga DNA in lymphocytes that are activated and allows the virus to remain LPM2 limiting latent gene expression in the membrane. This minimal expression of the repertoire of viral proteins allows the virus to minimize the number of targets for the immune system. (more…)

Antigenic Structure

When infection occurs cell begins production of viral proteins. These proteins include early antigen (EA), the capsid (VCA) and membrane glycoproteins (MA).

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Viral Pathogenesis and Persistence

The virus is transmitted by infected saliva and reaches the oropharynx epithelial cells where it replicates in production of virions and cell lysis. B cells are infected as they pass through the oropharynx or the epithelium of the postnasal space. The virus uses the cell to contact one of its envelope protein, gp350, which binds to the cellular receptor CD21 (the same that has for the C3d of complement). (more…)

Introduction

The Epstein-Barr virus (EBV) is a human herpes virus type 4, lymphotropic, providing for cells whose latent infection. It has been shown that this virus is mainly responsible for Infect mononucleosis (IM), a disease of adolescence and childhood.

It can also produce certain forms of cancer, including undifferentiated nasopharyngeal carcinoma (CNI), Endemic Burkitt’s Lymphoma (LBE) or B cell lymphomas in patients with acquired or congenital immunodeficiencies and there is great controversy over the role of this virus as a cause of chronic illness, in particular in regard to the Chronic Fatigue Syndrome (CFS).

Structure

Like every family is a large virus, encapsulated with a double-stranded DNA. It is about 150 nm.Its capsid is icosahedral with 162 capsomers and all the virus is enveloped by a cover with glycoproteins. (more…)