Clinical evaluation of automated cytomegalovirus IgG, IgM and IgG avidity assays for the LIAISON XL® analyser platform

Abstract

Min (AU/mL) Max (AU/mL) 25 97 22 65.9 6 60.3 5 50 5 50 5 47 The CMV LIAISON® XL CLIA-IgM assay showed a very good specificity in samples from active and no active CMV infection compared to that one found with Architect CMIA-IgM assay (98.4% versus 12.7%). We observed a very good agreement between the results obtained from CLIA-IgM and IB-IgM tests. Among the 63 serum samples from cord blood donors, 62 were positive or negative with both assays whereas the CMIAIgM test was in agreement with IB-IgM test in only 8 of the 63 samples. In pregnancy, the most important requirement for a CMV IgG avidity assay is to help in identifying or excluding a primary infection occurring in the previous 3 months in women presenting with a positive CMV IgM result. The 98% of samples taken 180 days after infection onset were reported as high-avidity CMV IgG by the LIAISON® XL CMV IgG Avidity assay. Between 90 and 120 days after infection onset the percentage of samples with low-moderate IgG avidity was still very high (76.5%). A mixture of low-moderate avidity and high-avidity were observed in samples taken 120–180 days after infection onset. The latter observation is consistent with the fact that the kinetics of the IgG avidity maturation process is likely to vary between individuals. Therefore, the LIAISON® XL system appears useful for accurately diagnosing of CMV infection in pregnant women. CONCLUSION