A-279 Evaluation of the Abbott Alinity i CMV IgG vs DiaSorin Liaison CMV IgG

Background CMV or cytomegalovirus infections are very common in most countries worldwide. The danger arises in pregnancy if mothers do not have pre-existing IgG antibodies for the virus, as acute infections or re-activation of the virus are harmful to the fetus. Depending on clinical symptoms, pregnant mothers may be screened for the presence of anti-CMV IgG. Methods The Alinity i CMV IgG assay is a chemiluminescent microparticle immunoassay (CMIA) and awas compared to the FDA-cleared Liason CMV IgG assay on a cohort of 153 specimens. Discrepancies between the assays were further tested for Avidity and CMV IgM. Results Correlation between the Alinity and the Liason CMV IgG methods showed an r of 0.91, Concordance as measured was excellent with a Kappa of 0.96 (0.92 to 1.00). Of the 153 specimens tested, 74 were positives, 76 negatives by both methods. 3 specimens were discrepant between the methods: 1 Liason low positive and Alinity non-reactive, 1 Liason negative and Alinity Grayzone, and 1 Liason negative and Alinity reactive. The discrepant reflex testing indicated that the specimen showing grayzone /negative results was also IgM positive (therefore and acute infection) and the specimen showing positive Alinity/ negative Liaison results was negative for IgM and a high avidity specimen. Conclusion The Alinity I and the Liaison CMV IgG assays demonstrated excellent concordance and correlation.