Antibody response to Epstein-Barr virus in infectious mononucleosis.

Altogether 171 serum specimens from 58 patients with heterophil antibody-positive infectious monomucleosis were studied for antibody response to Epstein-Barr virus (EBV). The sera were tested for fluorescent immunoglobulin G (IgG) and IgM gel-precipitating (GP) and complement-fixing (CF) antibodies to EBV. All 58 patients had IgG and IgM antibodies to EBV. Both IgG and IgM antibodies developed rapidly; the IgM antibodies disappeared within 8 to 10 weeks, whereas the IgG antibodies remained at an almost constant level. The development of IgG antibodies was so rapid that a fourfold or greater rise in titers was noted only in 22% of the patients. Both GP and CF antibodies to EBV (crude P3HR-1 Burkitt cell antigen) developed slowly; the mean titers kept rising for more than 12 weeks. The micro GP technique seemed to be more sensitive than the CF method, because 86% of the patients with infectious mononucleosis had GP antibodies compared with 72% having CF antibodies. In patients with infectious mononucleosis, a seroconversion or significant rise in GP antibodies was noted in 57%, whereas only 19% had a similar change in CF antibodies. The most promising of these antibody assays in the diagnosis of recent infections was the EBV-specific IgM antibody technique, which enables one to make the diagnosis on the basis of only one serum specimen. In cases where the acute-phase serum specimen is missing, the diagnosis can be made later by using the GP and CF techniques.