Introduction Human cytomegalovirus CMV is a herpesvirus

Introduction Human cytomegalovirus (CMV) is a herpesvirus which has a ubiquitous and worldwide distribution, and is the most frequent cause of congenital infection (Kenneson and Cannon, 2007). The prevalence is around 0.5–1% of all live births and is the leading cause of sensorineural hearing loss and mental retardation (Dollard et al., 2007, Stagno, 1986). CMV congenital infection can result from primary infection, reinfection, or reactivation among pregnant women. The risk of vertical transmission from mothers with primary infection during pregnancy ranges from 30% to 45% (Bodeus et al., 2010, Enders et al., 2011, Liesnard et al., 2000, Picone et al., 2013, Revello et al., 2011), and the risk is going down to 1.4% in case of nonprimary infection (Kenneson and Cannon, 2007). In order to counsel about the fetal risk, it WIN 18446 is of major importance to differentiate CMV primary infections occurring before pregnancy from those occurring during pregnancy. The maternal infection is mostly asymptomatic, and when symptoms are present, they are mostly mild (Daiminger et al., 2005). Particularly before 12–14 weeks of gestation, the presence of IgG and IgM without knowing about the previous serologic status can be a source of anxiety for parents and of difficult management for professionals. Supplementary tests are then needed to define primary infection onset. IgG avidity assays are widely used in case of positive IgG and IgM in pregnant women. These tests determine the strength of antigen–antibody bond, which increases over time after the primary infection. The IgG avidity is initially low during the early weeks and will mature to high avidity a few months after primary infection (Prince and Lapé-Nixon, 2014). In 12–25% of cases, the result of these conventional IgG avidity assays is inconclusive (intermediate avidity index); therefore, other markers are needed to help to date the onset of CMV primary infection (Enders et al., 2014, Leruez-Ville et al., 2013, Prince and Lapé-Nixon, 2014). Recently, other assays such as reactivity against specific CMV antigens and neutralizing antibodies were reported as additional tools for dating the onset of primary infection in pregnancy (Enders et al., 2013, Lilleri et al., 2016). In this study, we aimed first to evaluate the ability of the line immunoassays Mikrogen recomLine CMV IgG and recomLine CMV IgG Avidity (Mikrogen GmbH, Neuried, Germany) to date the onset of CMV primary infection comparing to VIDAS CMV IgG Avidity (bioMérieux, Marcy l\'Etoile, France) and, secondly, to evaluate the added value of the combination of recomLine CMV IgG and recomLine CMV IgG Avidity in cases of intermediate VIDAS avidity.
Study design
Results
Discussion In this study, we evaluated the performance of the recomLine IgG and IgG Avidity with a total of 178 samples. Half of them came from women with precisely determined onset of CMV primary infection, and half of them were sera with an intermediate VIDAS IgG avidity.