Congenital Asymptomatic Cytomegalovirus Infection: A Comparison of Specific IgM Antibody Test and pp65 Antigenemia Assay

ABSTRACT

PURPOSE: It is increasingly important to diagnosis asymptomatic infections which make up a majority (90%) of congenital cytomegalovirus (CMV) infections and that they may have sequeles such as sensorineural hearing loss and mental retardation. Recently antigenemia assay has been developed by using monoclonal antibodies against early structural protein pp65 of CMV. This CMV antigenemia assay seems to be more quicker to diagnosis than conventional viral culture or other tests. In this study, we evaluated the CMV antigenemia assay in neonatal congenital asymptomatic CMV infections comparing it to the CMV specific IgM test that uses enzyme immunoassay. METHODS: From October 1995 to May 1996, 231 normal term newborns delivered with asymptomatic in St. Holy Hospital of Catholic University were included. The CMV antigenemia assay was performed with CMV-vueTM Kit by immunocytochemical staining and the CMV specific IgM test was performed with Enzygnost Anti-CMV/IgM by using an enzyme immunoassay. RESULTS: Three cases (male 2, female 1) were CMV pp65 antigenemia assay positive, but none of them were CMV specific IgM antibody test positive. The CMV pp65 antigenemia assay was more sensitive than CMV specific IgM antibody test for detection of congenital asymptomatic CMV infections by 1.3% and 0%, respectively. CONCLUSION: According to previous results, we suggest that the rate of congenital CMV infections using only CMV specific IgM tests have been underestimated. We recommend the CMV antigenemia assay as the preferred method for more rapid and accurate diagnosis of CMV infections. And congenital asymptomatic CMV infections should be diagnosed and followed up because of possible future sequeles.