Quantitation of immunoglobulin E antibody to cytomegalovirus by antibody capture enzyme-linked immunosorbent assay

An antibody capture enzyme-linked immunosorbent assay was developed for detection of immunoglobulin E antibody to cytomegalovirus (CMV-IgE). Affinity-purified anti-human IgE-coated microtiter plates were used to separate IgE from other classes of antibody in serum. Virus-specific IgE was detected by subsequent incubation with horseradish peroxidase-labeled CMV antigen and substrate. The assay was shown to be very sensitive, since in most positive sera CMV-IgE was still detected at a dilution of 1:5,000. Of 45 patients with primary CMV infection, 43 (96%) were found to produce CMV-IgE. In contrast, CMV-IgE was detected in only 4 (9%) of 44 patients with recurrent CMV infection and in 1 of 144 healthy controls. Furthermore, the level of CMV-IgE in patients with recurrent CMV infection appeared to be lower than that in patients with primary infection. Preliminary examination of successive sera suggested that CMV-IgE is produced somewhat slower than CMV-IgM and -IgA but persists for a shorter period. These results suggest that CMV-IgE may be used as an indicator of primary CMV infection.