Evaluation of the Abbott AxSYM Cytomegalovirus (CMV) Immunoglobulin M (IgM) Assay in Conjunction with Other CMV IgM Tests and a CMV IgG Avidity Assay

Lazzarotto, Tiziana; Galli, Claudio; Pulvirenti, R.; Rescaldani, R; Vezzo, Roberto; Gioia, Antonio La; Martinelli, Canio; Rocca, Salvatore; Agresti, G.; Grillner, Lena; Nordin, Margareta; Ranst, Marc Van; Combs, B.; Maine, Gregory T.; Landini, M.P.

doi:10.1128/cdli.8.1.196-198.2001

Cited by 42 publications

(32 citation statements)

References 22 publications

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“…There is no "gold standard" for the determination of CMV IgM antibodies. Therefore, in several studies, one of the tests is chosen to be the standard or the majority of test results in agreement by different methods is considered the true test result (8,11). Of course, such an approach has important limitations.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of the New Architect Cytomegalovirus Immunoglobulin M (IgM), IgG, and IgG Avidity Assays

et al. 2009

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A panel of new cytomegalovirus (CMV) assays for use on the Architect instrument has been developed, including a CMV avidity assay based on a new technology. The purpose of this study was to compare the performance characteristics of the fully automated CMV immunoglobulin M (IgM), IgG, and IgG avidity tests on the Architect instrument with those of other available assays. A total of 503 consecutive fresh patient serum specimens (routine serum specimens) and 96 serum specimens from 33 pregnant women with a recent CMV primary infection (seroconversion serum specimens) were tested for CMV IgM and IgG by the Architect (Abbott), Vidas (BioMérieux), and Enzygnost (Siemens) assays. The seroconversion sera and 100 preselected serum specimens IgM negative and IgG positive by the AxSYM assay were also tested by the IgG avidity tests on the Architect and Vidas instruments. The relative agreements for CMV IgM determination with routine sera between the Architect assay and the Vidas, Enzygnost, and AxSYM assays were 97%, 94%, and 93%, respectively, for the CMV IgM tests and 99%, 98%, and 98%, respectively, for the CMV IgG tests. The specificities of the CMV IgG avidity test were 98% for the Architect assay and 76% for the Vidas assay. No high CMV IgG avidity test results were found within the first 3 months after seroconversion by either of those assays. The correlation between the results of the newly developed CMV IgM and IgG tests on the Architect instrument with the Vidas and Enzygnost assays was excellent (>94%). The CMV IgG avidity test reliably excluded patients with recent infections and showed an excellent specificity (98%).Human cytomegalovirus (CMV) is the most common cause of congenital infection. Primary infections occur in 0.15 to 2.0% of all pregnancies. The in utero transmission of CMV can take place during primary maternal infection or during nonprimary infection (reactivation and reinfection) of seropositive mothers, but the transmission rate to the fetus is much higher for nonimmune mothers (up to 40%) than for immune mothers (0 to 1%) (16). Fowler et al. showed that naturally acquired immunity results in a 69% reduction in the risk of congenital CMV infection in future pregnancies (2).Screening of pregnant women for CMV antibodies is a controversial issue and is not supported by international guidelines. Opponents of screening for CMV antibodies during pregnancy suggest that no clearly effective intervention is available. In addition, no tests can reliably predict which infected fetuses will have serious sequelae. The prognostic value of determination of the viral load in amniotic fluid is still a matter of debate and has the disadvantage of its invasive character (3,5,7,10,13,15). On the other hand, many parents wish to have an antenatal diagnosis of intrauterine infections, and gynecologists generally offer screening for CMV antibodies. Prenatal screening certainly has advantages, such as the fact that the use of precautionary hygienic measures can be suggested to CMV-seronegative pregnant women. The kno...

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Section: Discussionmentioning

confidence: 99%

Evaluation of the New Architect Cytomegalovirus Immunoglobulin M (IgM), IgG, and IgG Avidity Assays

et al. 2009

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“…After the initial onset of infection the rise in IgM titer may occur prior to the rise in IgG titer, making CMV IgG avidity testing reliant on the sensitivity of the CMV IgM test. To ensure that all CMV IgM-positive samples were detected and screened for IgG avidity, the AxSYM/IMx CMV IgM test was used, since it is one of the most sensitive commercial CMV IgM tests available (11,32,38). In agreement with published findings, the rate of IgM detection by the AxSYM/IMx was greater (5.7%) than the rate of the Eti-Cytok IgM (1.8%).…”

Section: Discussionmentioning

confidence: 99%

“…CMV IgG and IgM were detected in patient serum by using a commercial microparticle enzyme immunoassay (Abbott AxSYM; Abbott Laboratories). An IgG avidity assay (CMV IgG avidity EIA; Radim, Rome, Italy) was used to distinguish between primary and recurrent CMV infections (32). A second commercially available CMV-IgM enzyme immunoassay (Eti-Cytok IgM; Sorin Biomedica, Vercelli, Italy) was also used on all sera.…”

Section: Patientsmentioning

confidence: 99%

Diagnosis of and Screening for Cytomegalovirus Infection in Pregnant Women

et al. 2005

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No single diagnostic test for cytomegalovirus (CMV) infection is currently available for pregnant women at all stages of gestation. Improved accuracy in estimating the timing of primary infections can be used to identify women at higher risk of giving birth to congenitally infected infants. A diagnostic algorithm utilizing immunoglobulin G (IgG), IgM, and IgG avidity was used to prospectively screen serum from 600 pregnant women enrolled from two groups: <20 weeks gestation (n ‫؍‬ 396) or >20 weeks gestation (n ‫؍‬ 204). PCR testing of urine and/or blood was performed on all seropositive women (n ‫؍‬ 341). The majority (56.8%) of women were CMV IgG seropositive, with 5.5% being also CMV IgM positive. In the IgM-positive women, 1.2% had a low-avidity IgG, indicating a primary CMV infection and a high risk of intrauterine transmission. Two infants with asymptomatic CMV infection were born of mothers who had seroconverted in the second trimester of pregnancy. Baseline, age-stratified CMV serostatus was established from 1,018 blood donors. Baseline seropositivity from a blood donor population increased with age from 34.9% seroprevalence at less than 20 years of age to 72% seroprevalence at 50 years of age. Women at high risk of intrauterine transmission of CMV were identified at all stages of gestation. Women infected with CMV during late gestation may be more likely to transmit the virus, so failure to detect seroconversions in late gestation may result in failure to detect infected neonates.Human cytomegalovirus (CMV) is the most common cause of congenital malformation resulting from viral intrauterine infection in developed countries (12,21,48). Primary CMV infection occurs in 0.15 to 2.0% of all pregnancies and may be transmitted to the fetus in up to 40% of cases (48). Up to 15% of intrauterine CMV infections result in symptomatic congenital disease at birth, and 10 to 15% of those born with asymptomatic congenital CMV will develop significant clinical sequelae in infancy (7,10,18). In utero transmission of CMV can occur during primary maternal infection, reactivation, or reinfection of seropositive mothers. Most concern centers on primary maternal infection, due to the potential for significant fetal damage when the infection is acquired and transmitted during the first trimester (30, 48). Perinatal infections can result through virus transmission from many parts of the birth canal (39); however, the majority of these infections are asymptomatic (43).The usefulness of prenatal testing for CMV has been questioned due to the absence of clearly effective intervention (1, 27) and to evidence for severe congenital malformation resulting from viral reactivation (6,8,20). Continuing advancements in technology, however, mean reliable and inexpensive serologic tests are available, prenatal diagnostic procedures with acceptable negative predictive values (NPV) can be performed, and trials of neonatal antiviral treatments are ongoing (25,34,37,50,52). Proposed diagnostic algorithms have focused on first-trimester screeni...

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“…Avidity tests have been developed for rubella virus (17), Toxoplasma gondii (5,8,18), cytomegalovirus (CMV) (1), varicella-zoster virus (11), human immunodeficiency virus (25), hepatitis viruses (22,26,27,29), Epstein-Barr virus (28), and others. For immunocompetent, untreated individuals, the presence of low-avidity IgG directed against pathogens may indicate a recent infection, whereas the presence of high-avidity IgG excludes a primary infection (13,14). During the early immune response, IgG antibodies are targeting a multiplicity of different epitopes of the pathogen with relatively low avidity.…”

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Development of Fully Automated Determination of Marker-Specific Immunoglobulin G (IgG) Avidity Based on the Avidity Competition Assay Format: Application for Abbott Architect Cytomegalovirus and Toxo IgG Avidity Assays

et al. 2009

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Determination of the avidity of immunoglobulin G (IgG) directed against a specific marker has become an established diagnostic tool for identifying or excluding acute infections with pathogens. A novel assay format termed AVIcomp (avidity competition based on mass action) circumventing the conventional chaotropic format has been developed for determination of the avidity of marker-specific IgG in patient specimens. Its applications for cytomegalovirus (CMV) and Toxoplasma gondii are presented. Specific high-avidity IgG from the patient specimen is selectively blocked using a soluble antigen in a sample pretreatment reagent, and the amount of remaining specific low-avidity IgG is determined relative to that in an untreated control. The comparison of the conventional chaotropic format, represented by the Radim CMV IgG Avidity assay, and the newly developed AVIcomp method, as exemplified by the Architect CMV IgG Avidity assay, on blood drawn within 4 months after seroconversion revealed a sensitivity of 100% (97.3% by an alternative calculation) for the AVIcomp format versus 87.5% (75.7% by an alternative calculation) for the chaotropic avidity assay. The specificity on 312 CMV IgG reactive and CMV IgM nonreactive specimens from pregnant women was 100% for the AVIcomp assay and 99.7% for the conventional avidity assay. The Architect Toxo IgG Avidity assay showed an agreement of 97.2% with the bioMérieux Vidas Toxo IgG Avidity Assay employing chaotropic reagents. These performance data suggest that the AVIcomp format shows superior sensitivity and equivalent specificity for the determination of IgG avidity to assays based on the chaotropic method and that the AVIcomp format may also be applicable to other disease states.Over recent years, numerous publications have shown that the avidity of marker-specific immunoglobulin G (IgG) is a suitable tool for distinguishing between acute and recurrent or past infection with a pathogen (7). Avidity tests have been developed for rubella virus (17), Toxoplasma gondii (5,8,18), cytomegalovirus (CMV) (1), varicella-zoster virus (11), human immunodeficiency virus (25), hepatitis viruses (22,26,27,29), Epstein-Barr virus (28), and others. For immunocompetent, untreated individuals, the presence of low-avidity IgG directed against pathogens may indicate a recent infection, whereas the presence of high-avidity IgG excludes a primary infection (13,14). During the early immune response, IgG antibodies are targeting a multiplicity of different epitopes of the pathogen with relatively low avidity. Clonal selection finally results in high-avidity antibodies directed mainly against a limited number of immunodominant epitopes (5).For T. gondii infections, high-avidity IgG serves to rule out a recent infection as well; however, low-avidity results are not indicative of a recent or past infection (16). This is due to the fact that the antibody avidity maturation kinetics for T. gondii

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Evaluation of the Abbott AxSYM Cytomegalovirus (CMV) Immunoglobulin M (IgM) Assay in Conjunction with Other CMV IgM Tests and a CMV IgG Avidity Assay

Cited by 42 publications

References 22 publications

Evaluation of the New Architect Cytomegalovirus Immunoglobulin M (IgM), IgG, and IgG Avidity Assays

Evaluation of the New Architect Cytomegalovirus Immunoglobulin M (IgM), IgG, and IgG Avidity Assays

Diagnosis of and Screening for Cytomegalovirus Infection in Pregnant Women

Development of Fully Automated Determination of Marker-Specific Immunoglobulin G (IgG) Avidity Based on the Avidity Competition Assay Format: Application for Abbott Architect Cytomegalovirus and Toxo IgG Avidity Assays

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