Early primary infection and high Epstein-Barr virus antibody titers in Greenland Eskimos at high risk for nasopharyngeal carcinoma.

In a comparative study of populations at high and low risk of nasopharyngeal carcinoma (NPC), sera from 442 Eskimo and 770 Danish children and adolescents were tested for the presence of antibodies against Epstein-Barr virus (EBV). Eskimo children in Greenland were seropositive at an early age and showed significantly higher titers of IgG antibody to the viral capsid antigen (VCA) (p less than 0.0001) and soluble (S) antigen (p less than 0.005) than Danes matched for age and sex, but had similar levels of IgA antibody to VCA and IgG antibody to the early antigen (EA). The high geometric mean VCA (IgG) titers found in certain age groups of Eskimo children were as high as those previously reported from areas in Africa highly endemic for Burkitt's lymphoma. In Greenland, neither location nor household size was a determining factor for prevalence or titer of VCA (IgG). The high antibody titers among Eskimo children probably reflect exposure to a large inoculum of EBV at the time of primary infection, infection early in life and/or re-exposure due to the higher incidence of EBV infection in Greenland. In view of the high incidence of NPC in Greenland and the known association of this tumor with EBV, we speculate that the time and quantitative aspects of the primary infection are also factors of relevance in the etiology of NPC.