The significance of serum IgM, IgA and IgG antibodies specific for Epstein-Barr virus as determined by immunoperoxidase assay in the rapid diagnosis of infectious mononucleosis

The feasibility of using serum IgM, IgA and IgG antibodies specific to Epstein-Barr virus (EBV) viral capsid antigen (VCA), as determined by immunoperoxidase assay (IPA), for the early diagnosis of mononucleosis was evaluated in 65 patients with infectious mononucleosis (IMN). Control groups consisted of 104 healthy students and 15 cytomegalovirus-infected patients. In the first serum sample obtained upon admission, IgM antibodies (titer ≥ 64) to EBV VCA were found in 64 of the 65 IMN patients (98%), while EBV-VCA IgA antibodies (titer ≥ 32) were found in 32 patients (49%). In those particular titers, no EBV-VCA IgM or IgA antibodies were found in any of the control sera. EBV-VCA-specific IgM antibodies were also not detected in any of the 15 patients with cytomegalovirus infection. In sera obtained from IMN patients within 10 days of the onset of symptoms, 18 of 19 (95%) were IgM seropositive. This study demonstrates that serum EBV-VCA IgM antibodies (titer ≥ 64) as determined by IPA are highly specific (100%) and highly sensitive (98%) and can be of value for the early and rapid diagnosis of EBV-IMN infection.