- Complete panel for the diagnosis of the CMV infection, including CMV IgG, IgM and IgG Avidity
- The Avidity assay can be run in the early stage of acute infection due to the high sensitivity of the IgG tests
- The IgM titer decrease is correlated to the increasing value of the IgG avidity index
The CMV IgG Avidity test is a chemiluminescent immunoassay (CLIA), for use on IDS automated analyzers, for the quantitative determination of Avidity Index of specific IgG class antibodies directed against Cytomegalovirus (CMV) in samples of human serum or plasma (K3-EDTA, Sodium Citrate). The possibility of differentiating antibodies at high avidity from low avidity allows to supply interesting clinical information.
This assay is used as a diagnostic aid when assessing immunity status of patients related to CMV (Cytomegalovirus) infection.
Human Cytomegalovirus belongs to the herpes virus family. It is typically abbreviated as HCMV and is alternatively known as human herpesvirus-5 ( HCMV-5). Although it may be found throughout the body, HCMV infections are frequently associated with the salivary glands1.
HCMV infection is typically unnoticed in healthy people, but can be life-threatening for the immunocompromised, such as HIV-infected persons, organ transplant recipients, or newborn infants2.
After primary infection, HCMV is not eradicated but establishes life-long infection in its host. Worldwide seroprevalence in adults, in the general population, varies from 40 to 90 %4.
In pregnant women, distinguishing the primary from non-primary HCMV infection is important, since the former is much more deleterious to the fetus than the latter9. This is also true for immunocompromised patients, in whom primary infections are often accompanied by symptoms, whereas non-primary infection is usually asymptomatic10.
The serological diagnosis of recently acquired HCMV infection is based on the detection of specific IgM antibodies, seroconversion or a significant increase in specific IgG antibody concentrations.
In addition to IgM and IgG determinations immunoglobulin G avidity testing has been shown to be useful for differentiating recent from past cytomegalovirus infection15 and investigating suspected CMV in pregnant women16 .
- Koichi Y,Arvin AM, G. Campadelli-Fiume, Mocarski E, Moore P, Roizman B, Whitley R (2007). Human herpesviruses : biology,therapy and immunoprophylaxis. Cambridge,UK : Cambridge University Press. ISBN 0-521-82714-0
- Ryan KJ, Ray CG ( editors ) ( 2004 ). Sherris Medical Microbiology ( 4th ). McGraw Hill. Pp. 556;566-9. ISBN 0-8385-8529-9.
- Hummel M, Abecassis MM. A model for reactivation of CMV from latency. J. Clin. Virol. 2002; 25 Suppl 2 : S123-36.
- Dowd JB, Aiello AE, Alley DE ( 2009 ). Socioeconomic disparities in the seroprevalence of cytomegalovirus infection in the US population: NHANES III. Epidemiol. Infect. , 137: 58-65.
- Sweet C. The pathogenicity of Cytomegalovirus. FEMS Microbiol. Rev.,23 : 457-482
- Azam AZ, Vial Y, Fawer CL,Zufferey J, Hohlfeld P. Prenatal diagnosis of congenital cytomegalovirus infection. Obstet. And Gynec., 97:443-448,2001.
- Stagno S, Pass RF, Cloud G et al. Primary Cytomegalovirus infection in pregnancy. Incidence, transmission to fetus and clinical outcome. J. Amer. Med. Ass., 256: 1904-1908,1986.
- Lazzarotto T,Gabrielli L, Lanari M, Guerra B, Bellucci T, Sassi M, Landini MP. Congenital cytomegalovirus infection: recent advances in the diagnosis of maternal infection. Hum. Immunol. 2004 May; 65(5) : 410-415.
- Van De Meer JTM, Drew WL, Bowden RA et al. Summary of the international consensus symposium on advances in the diagnosis, treatment and prophylaxis of cytomegalovirus infection. Antivir. Res., 32: 119-140,1996.
- Lazzarotto T, Spezzacatena P, Pradelli P. et al. Avidity of immunoglobulin G directed again human cytomegalovirus during primary and secondary infections in immunocompetent and immnucompromised patients. Clin. Diagn. Lab. Immunol., 4: 469-473, 1997.
- Söderberg-Nauclé C, Fish KN, Nelson JA. Reactivation of latent human cytomegalovirus by allogenic stimulation of blood cells from healthy donors. Cell 1997; 91:119.
- Ross SA, Arora N, Novak Z, et al. Cytomegalovirus reinfections in healthy seroimmune women. J Infect Dis 2010; 201:386.
- Deyi YM, Goubau P, Bodéus M. False positive IgM antibody tests for cytomegalovirus in patients with acute Epstein-Barr virus infection. Europ. J. Clin. Microbiol. Infect. Dis., 19: 557-560, 2000.
- Rawlinson WD. Broadsheet number 50 : Diagnosis of human cytomegalovirus infection and disease. Pathology,31 : 109-115,1999.
- Chakravarti A, Kashyap B, Wadhwa A. Relationship of IgG avidity and IgM levels for the differential diagnosis of primary from recurrent cytomegalovirus infections. Iran J Allergy Asthma Immunol 2007; 684) : 197-201.
- Grangeot-Keros L, Mayaux MJ, Lebon P. et al.. Value of cytomegalovirus IgG avidity index for the diagnosis of primary CMV infection in pregnant women. J. Infect. Dis. 175 : 944-966,1997.