Epstein-Barr virus-specific serum immunoglobulin A as an acute-phase antibody in infectious mononucleosis

Abstract

Immunoglobulin (Ig) A antibodies [Ab] to Epstein-Barr virus [EBV] viral capsid antigen [Ag] were assayed serially in 19 patients with infectious mononucleosis and in 38 controls. Of infectious mononucleosis patients, 74% demonstrated IgA Ab, whereas this was found in 13% of controls. This Ab appeared early in infectious mononucleosis and was virtually gone 10 wk after onset. Comparison of IgA Ab kinetics was made with IgG and IgM Ab to viral capsid Ab, heterophile Ab and Ab to EBV early Ag and nuclear Ag. Failure to demonstrate IgA Ab was associated with severe illness, prolonged illness, delay in IgG and anti-EBV nuclear Ag Ab and low or absent heterophile and anti-early Ag Ab. Assay of IgA Ab to viral capsid Ag is a potentially useful adjunct in the serodiagnosis of infectious mononucleosis or recent EBV infection, as are the other Ab tested. IgM viral capsid Ag Ab was the only acute-phase Ab present in all patients.