Improvement of serological diagnosis of neonatal cytomegalovirus infection by simultaneously testing for specific immunoglobulins E and M by antibody-capture enzyme-linked immunosorbent assay.

This study describes the results of testing 92 serum samples, including 10 umbilical cord serum samples, from 38 cytomegalovirus (CMV)-infected neonates for CMV-specific immunoglobulins E (IgE) and M by antibody-capture enzyme-linked immunosorbent assays with enzyme-labeled CMV antigen. All infants excreted CMV in the urine. It was demonstrated that the CMV IgE test was more sensitive than the CMV IgM test in diagnosing CMV infection in neonates by serology. Thus, the sensitivity for the IgE test was 82%, whereas for the IgM test it was only 66%. Furthermore, the CMV-specific IgE response, expressed as absorbance, was higher than the specific IgM response in 91% of the 76 sera which contained antibodies of either one or both immunoglobulin classes. Forty-six control sera, including 18 umbilical cord sera, from 46 neonates from whom CMV was not isolated were also tested. Most sera were negative. Three infants, however, had CMV antibodies of one or both classes, indicating infection. The level of total serum IgE was controlled in 24 of the sera from the CMV-infected neonates, but in none of the cases was the level elevated. No correlation was found between the reactivity of the antibodies in the two immunoglobulin classes and the level of CMV in urine.