Infectious Mononucleosis: Appearance of Neutralizing Antibody to Epstein-Barr Virus Measured by Inhibition of Formation of Lymphoblastoid Cell Lines

Abstract

Sera taken before illness and during convalescence from patients with infectious mononucleosis (IM) were examined for their ability to neutralize the capacity of Epstein-Barr virus (EBV) to stimulate formation of lymphoblastoid cell lines from human leukocytes in vitro. Neutralizing activity was not detected in 13 of 15 sera taken before illness and was present at a dilution of 1:4 or higher in all of 24 sera taken after illness. EBV-neutralizing activity was found in sera collected during the first week of illness and was also demonstrated in a serum obtained many years after illness. The titer of neutralizing activity in sera of two patients studied sequentially did not change significantly during the first year after 1M. The results demonstrate appearance of EBV-neutralizing antibody in 1M and support previous seroepidemiologic studies which indicate that EBV is the etiologic agent of IM.