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CMV IgG avidity assays are widely used and can be helpful in pregnant women to date the onset of CMV primary infection; however, these tests are not standardized and sometimes give inconclusive results. We evaluated the performances of Mikrogen recomLine CMV IgG and IgG Avidity compared to the VIDAS CMV IgG Avidity. On a first sample set of 89 sequential sera collected from 40 women with precisely determined onset of CMV primary infection, the combination of Mikrogen recomLine CMV IgG and IgG Avidity showed an accurate interpretation in 83.1% (74/89), an incorrect result in 4.5% (4/89), and an inconclusive result in 12.4% (11/89) and showed a better sensitivity to diagnose infections14 weeks compared to VIDAS (85.9% vs. 76.9%). On a second sample set of 89 sera with an intermediate VIDAS CMV IgG Avidity, the combination of line immunoassays provided additional information on the time of infection in 79% (70/89) of the samples. This combination of line assays is useful as additional confirmatory testing and can help to date more precisely the onset of CMV primary infection.

When acquired during pregnancy toxoplasmosis can have devastating consequences on the fetus. As maternal infection is in the majority of cases subclinical, the diagnosis of toxoplasmosis relies on serological tests for the detection of IgG, IGM and the mesure of IgG avidity. We evaluated the performance of IDS-iSYS a new automatized instrument based on chemiluminescence for the diagnosis of the disease. Our study was based on non-selected samples received in our laboratory either for the determination of serological status or for distinguishing acute from chronic infection. Seven hundred eighty three samples were enrolled in the study. Compared with Architect IgG and IgM assays, the sensitivity and specificity were respectively 99% and 99% for IgG, and 75% and 97% for IgM. We observed higher remaining titers for IDS iSYS IgG, which could reduce the proportions of patients who have to be retested because of doubtful titers. IgM detection and avidity scored equivalent performance with both methods. This automate appears to be a reliable and easy-to-use tool for diagnosing toxoplasmosis in different clinical settings.

This study evaluates the inclusion of the IgG avidity index in ELISA to detect anti-Strongyloides stercoralis IgG. The ELISA index revealed 70% of specificity. With the inclusion of screening AI, specificity increased to 80%. IgG avidity complemented traditional IgG ELISA by eliminating some of the suspected or false positive cases.

The ARCHITECT Toxo IgG and IgG Avidity assays have been developed as a fully automated panel for immune status determination and acute infection exclusion. Resolved relative specificity and sensitivity of the ARCHITECT Toxo IgG assay were 99.6% (1359/1365) and 99.7% (1096/1099) as determined on pregnant females, blood donor, and diagnostic specimens. Seroconversion sensitivity of the ARCHITECT assay was comparable with the AxSYM Toxo IgG assay. The ARCHITECT Toxo IgG Avidity assay detected 100.0% (124/124) of acute phase specimens (

Retrospective evaluation of the kinetics of cytomegalovirus (CMV) seroconversion with CMV IgM, IgG, and IgG avidity assays, in a Swiss pregnant women population, has shown that the current published CMV serologic diagnostic algorithms were valid and fit for use. In 19% of the cases analyzed, CMV-specific IgM was detected before IgG.

Toxoplasmosis acquired during pregnancy exposes the fetus to congenital toxoplasmosis. Avidity tests are commonly used to date time of infection to evaluate the fetal risk and to offer prenatal diagnosis. This study evaluated and compared 2 commercial avidity tests: Platelia™ Toxo IgG Avidity (Bio-Rad, Marnes la Coquette, France) and Liaison® Toxo IgG Avidity II (Diasorin, Saluggia, Italy) kits. In complement, a study of specific IgG and IgM in the 2 systems was carried out. Sensitivity and specificity of the avidity tests were 94.4% and 87.8% for the Liaison® and 91.3% and 98.5% for the Platelia™ methods, respectively. Percentages of complete discrepancies, partial discrepancies, and agreement between both tests were 1.1%, 23.6%, and 75.3%, respectively. Moreover, the combination of both avidity tests may be useful in some cases. Indeed, that strategy permitted to confirm without delay a chronic toxoplasmosis in 23 cases and avoid treatment in these pregnant women.