Maintenance of Serum Immunoglobulin G Antibodies to Epstein-Barr Virus (EBV) Nuclear Antigen 2 in Healthy Individuals from Different Age Groups in a Japanese Population with a High Childhood Incidence of Asymptomatic Primary EBV Infection

Abstract

Immunoglobulin G (IgG) antibodies to Epstein-Barr virus (EBV) nuclear antigens 2 and 1 (EBNA-2 and EBNA-1, respectively) were studied using sera from healthy individuals of a population with a high incidence of asymptomatic primary EBV infections during infancy or childhood in Japan. Two CHO-K1 cell lines expressing EBNA-2 and EBNA-1 were used for anticomplement and indirect immunofluorescence assays. The positivity rate for EBNA-2 IgG rose in the 1-to 2-year age group, increased and remained at a plateau (ϳ45%) between 3 and 29 years of age (3-to 4-, 5-to 9-, 10-to 14-, and 15-to 29-year age groups), and then reached 98% by age 40 (>40-year age group). Both seropositivity for EBNA-1 and seropositivity for EBNAs in Raji cells (EBNA/Raji) were detected in the 1-to 2-year age group, remained high, and finally reached 100% by age 40. The geometric mean titer (GMT) of EBNA-2 IgG reached a plateau in the 5-to 9-and 10-to 14-year-old groups and remained elevated in the older age groups (15 to 29 and >40 years). The GMT of EBNA-1 IgGs increased to a plateau in the 1-to 2-year-old group and remained unchanged in the older age groups. The GMT of EBNA/Raji IgGs also reached a plateau in the 1-to 2-year-old group, remained level throughout the 3-to 14-year age groups, and decreased in the 15-to 29-year-olds. EBNA-2 IgGs emerged earlier than EBNA-1 IgGs in 8 of 10 patients with infectious mononucleosis, who were between 1 and 27 years old, and declined with time in three of eight cases. These results suggest that EBNA-2 IgG antibodies evoked in young children by asymptomatic primary EBV infections remain elevated throughout life, probably because of reactivation of latent and/or exogenous EBV superinfection.

Geographical Distribution of the Herpes Simplex Virus Type 1 BgK L Variant in Japan Suggests Gradual Dispersion of the Virus from Shikoku Island to the Other Islands

“…The seroprevalence of HSV-1 is high in Japan (44) compared to among the Caucasian population in the United States (37,38), similar to the situation with Epstein-Barr virus (6,10) and human herpesvirus 6 (41). It is noteworthy that, during the 1960s and 1970s (11,44), HSV-1 seroprevalence in Japan decreased to a level similar to that of the Caucasian population in the United States (37).…”

Age-Related EBV-Associated B-Cell Lymphoproliferative Disorders Constitute a Distinct Clinicopathologic Group: A Study of 96 Patients

“…EBV DNA in peripheral blood mononuclear cells was more frequently detected in healthy individuals older than 70 years of age (8 of 9, 89%) than in ones <70 years (1 of 11, 9%) using real-time PCR (26). Yanagi et al also showed that EBNA-2 IgG antibodies evoked in young children by asymptomatic primary EBV infections remain elevated throughout life using sera, suggesting the intervention of reactivation of latent and/or exogenous EBV superinfection (27). These data provided additional support on the speculation that age-related decline in immunity may be contributing to the pathogenesis of agerelated EBV+ B-cell LPDs.…”

Epstein-Barr Virus-Associated Primary Central Nervous System Lymphoma in the Japanese Population

“…32) Serological testing for EBV revealed that more than 90% of the infected people in Japan were infected during childhood or adolescence. 15) Infection usually occurs through contact with oral secretions. Primary infection often results in infectious mononucleosis.…”