This test detects the diffuse components of early antigen only. Fields Virology. Lippincott Williams and Wilkins; Lennette ET: Epstein-Barr virus.
Manual of Clinical Microbiology. ASM Press; An aliquot of the patient serum, sample diluent, and bead reagent are combined in a reaction vessel. After washing, antihuman-IgG antibody conjugated to phycoerythrin PE is added to the beads and incubated. Another wash step removes excess conjugate, and beads are subsequently resuspended in wash buffer. The bead mixture passes through a detector where the identity of each bead is determined by the bead's dye fluorescence.
In addition, the amount of antibody captured by the antigen is measured by the fluorescence of the bound PE. Bio-Rad Laboratories; Monday through Saturday. This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Excel Pdf.
Normal Reports Abnormal Reports. Test Catalog Test Catalog. Contact Search. Search Cancel. Home Test Catalog Overview. However, the profile of a minority of cases may give rise to doubts or require confirmation. Nevertheless, it is recommended to assess the specificity of the result because it may be made aspecific by interfering rheumatoid factor and autoantibodies, or cross-reacting factors such as HCMV or parvovirus B19[ 67 ]. A search for these factors and immunoblotting for IgM may be as helpful as the determination of other parameters of acute infection such as heterophilic antibodies or HBV DNA[ 98 ].
In some cases, VCA IgM may not be produced or appear wk after VCA IgG, or present for a very short time or at low concentrations and it may not be detected by conventional tests[ 2 , 32 , , ]. Furthermore, even when they are produced, they may be lost over time particularly, but not exclusively, in immunocompromised patients[ 23 , , ]. However, this last option inevitably delays the diagnosis until the second sample is collected, and physicians tend to avoid it if the symptoms improve over time, especially in the case of children, they may find it traumatic, which means the second sampling usually involves only a small number of patients[ ].
As anti-p18 IgG can be considered equivalent in meaning to EBNA-1 IgG because they are both produced late during EBV infection , their presence indicates past infection, and their absence indicates an acute infection. A VCA IgG avidity test can also be used to distinguish acute and past infection[ 64 , 67 ], which are respectively characterized by low and high levels of avidity; studies of patients with isolated VCA IgG have found low levels in about half of the cases, and high levels in the remaining half[ 75 , 86 ].
The detection of EBV DNA is particularly useful in the case of serologically indeterminate EBV infection[ 75 , 86 , 98 ] because its presence in serum or plasma indicates primary infection or reactivation[ 13 ]. A search for heterophile antibodies may be useful in patients with isolated VCA IgG if the result is positive, although there have been reports of their presence for mo[ 28 , 35 , 48 ].
However, nothing can be said in the absence of heterophile antibodies, especially in children aged less than 5 years, and other tests must be used. Reactivation is still relatively rare and often short in immunocompetent subjects, and is generally considered of no clinical relevance[ , ]; however, it can cause serious complications in immunocompromised patients.
Moreover, as false positive reactions may also result from the presence of autoantibodies or rheumatoid factor, it can be useful to look for these interfering factors. However, it needs to be pointed out that cold agglutinins, rheumatoid factor and autoantibodies can be found for a short period during the course of EBV mononucleosis because of the polyclonal activation of B-cells[ ], therefore, the presence of rheumatoid factor does not automatically mean a falsely positive VCA IgM result.
Finally, EBNA-1 IgG positivity in patients with primary infection may also result from aspecific reactivity, which can be detected by immunoblotting for IgG antibodies[ ]. Furthermore, the recently developed EIA for antibodies to EBNA-1 IgG based on recombinant or synthetic peptides may be more sensitive than its predecessors, and allow their identification early in the course of primary EBV infection[ ].
In addition to repeating the test after a reasonable period of time in order to detect any changes in the antibody profile, VCA IgG avidity has proved to be particularly useful because low levels of avidity have been found in the course of recent infection, and high levels in the course of past infection or reactivation[ 62 - 64 ].
In order to fully understand the IgG avidity test and evaluate the results in relation to antibody maturation time, it is important to know how long after the onset of symptoms the blood sample was taken. The use of molecular biology seems to be a rather delicate question.
Consequently, as EBV DNA is present in cases of reactivation or primary infection, it is unlikely that testing one sample will be able to distinguish the two situations[ 75 , 95 ]. Other antibodies have been found in cases of reactivation.
These antibodies reach a peak level wk after primary infection and decline slowly, but may last indefinitely. High levels were also found in patients with immunodeficiencies, recurrent parotitis, multiple sclerosis or nasopharyngeal cancer, as well as in pregnant women and elderly subjects[ 26 , - ]. Consequently, a search for VCA IgA is considered useful only in the diagnosis and management of patients with nasopharyngeal carcinoma[ - ].
At clinical level, the problem is to discover whether the patient has experienced a past infection or is still susceptible. As the doubt is to distinguish past infection and non-specificity, it is useless to search for heterophile antibodies or EBV DNA. One immunoblotting study found that such patients were not only all anti-p72 EBNA-1 positive, but also anti-p23 VCA positive, which was not detected by the screening tests using p18 antigen alone to detect VCA IgG[ ].
A number of tests have recently been developed that may help clarify doubtful results in the serological diagnosis of EBV infection, and it is now possible to reach a conclusion without having to wait for a second sample taken after a certain lapse of time.
What tests should be used after screening depends on various factors in addition to their scientific and technical suitability; these include organizational and economic questions such as differences in costs and the reimbursements foreseen by the National Health Service or insurance companies , as well as the availability of space and adequately trained personnel.
Furthermore, the number of routine tests the number of samples with inconclusive results affects the decision to undertake further more or less expensive laboratory tests or to send the sample or the patient to a reference laboratory.
Finally, the type of patient may also be decisive. In conclusion, considerable progress has been made in the serological diagnosis of EBV infection and, using appropriate algorithms and methodologies, it is possible to solve all of the problems that may arise during the course of routine laboratory practice. Independentei , Sect. National Center for Biotechnology Information , U. Journal List World J Virol v. World J Virol.
Published online Feb Massimo De Paschale and Pierangelo Clerici. Author information Article notes Copyright and License information Disclaimer. All rights reserved.
This article has been cited by other articles in PMC. Abstract Serological tests for antibodies specific for Epstein-Barr virus EBV antigens are frequently used to define infection status and for the differential diagnosis of other pathogens responsible for mononucleosis syndrome.
Table 1 Types of latency in Epstein-Barr virus-associated diseases. Open in a separate window. Table 2 Interpretation of Epstein-Barr virus serological profiles in immunocompetent patients. Table 3 Serological profiles in Epstein-Barr virus reactivation and some Epstein-Barr virus-associated diseases. Heterophile antibodies Heterophile antibodies are antibodies that agglutinate cells of other animal species that are mainly associated with mononucleosis due to EBV but may be, albeit rarely, also detected in other diseases[ 47 ].
Immunoblotting In order to confirm the screening assays, various immunoblotting tests have been developed using viral lysates of EBV-transformed cells and recombinant antigens line blots [ 57 ]. Table 4 Interpretation of IgG avidity test with immunoblotting. Molecular biology A number of different methods, techniques and protocols have been used to determine the presence of EBV DNA and measure viral load[ 69 - 72 ].
Table 5 Additional tests in the case of an isolated viral capsid antigen IgG pattern. EBV: Epstein-Barr virus. References 1. Rickinson AB, Kieff E. Epstein-Barr virus. Fields virology. Philadelphia: Lippincott Williams and Wilkins; Lennette ET. Diagnostic procedures for viral, rickettsial, and chlamydial infections. Washington: American Public Health Association; Steven NM. Infectious mononucleosis.
EBV Reports. Identification of Epstein-Barr virus-infected cells in tonsils of acute infectious mononucleosis by in situ hybridization. Hum Pathol. Epstein-Barr virus latency in blood mononuclear cells: analysis of viral gene transcription during primary infection and in the carrier state. J Virol. Cellular responses to viral infection in humans: lessons from Epstein-Barr virus. Annu Rev Immunol.
J Exp Med. A re-examination of the Epstein-Barr virus carrier state in healthy seropositive individuals. Int J Cancer.
Persistence of the Epstein-Barr virus and the origins of associated lymphomas. N Engl J Med. Leight ER, Sugden B. Rev Med Virol. Kieff E, Liebowitz D. Epstein-Barr virus and its replication.
New York: Raven Press; Thorley-Lawson DA. Epstein-Barr virus: exploiting the immune system. Published ahead of print 12 March National Center for Biotechnology Information , U.
Journal List Clin Vaccine Immunol v. Clin Vaccine Immunol. Author information Article notes Copyright and License information Disclaimer. Corresponding author. Address correspondence to David Navarro, se. Received Feb 25; Accepted Mar 3. All Rights Reserved. This article has been cited by other articles in PMC. Architect Epstein-Barr virus chemiluminescent microparticle immunoassays.
Immunofluorescence assays. Detection of heterophilic antibodies. Interpretation of Epstein-Barr virus serostatus. Statistical analysis. Open in a separate window. Sera displaying values within the gray zone of the respective assay were excluded from the analyses. Performance of the Architect assays for diagnosing clinically relevant Epstein-Barr virus infection statuses. Performance of the Architect assays with indeterminate Epstein-Barr virus serological profiles.
Footnotes Published ahead of print 12 March Hess RD. Routine Epstein-Barr virus diagnostics from the laboratory perspective: still challenging after 35 years. Evaluation of an immunofiltration assay that detects immunoglobulin M antibodies against the ZEBRA protein for the diagnosis of Epstein-Barr virus infectious mononucleosis in immunocompetent patients. Vaccine Immunol. Evaluation of four commercial systems for the diagnosis of Epstein-Barr virus primary infections.
Evaluation of four commercially available Epstein-Barr virus enzyme immunoassays with an immunofluorescence assay as the reference method. Healthcare providers can test for antibodies to the following EBV-associated antigens: This photomicrograph depicts leukemia cells that contain Epstein-Barr virus using an FA staining technique.
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