Epstein-Barr Virus (EBV) establishes life-long infection in Bcells, characterized by periods of latency and reactivation. Antibodies to viral capsid antigen (VCA) are often used to study the relationship of EBV with chronic diseases. While VCA-Immunoglobulin (Ig) G antibodies indicate past EBVexposure, VCA-IgA antibodies may reflect reactivation of latent infection. The present study examines occupational and environmental exposures in relation to EBV VCA-IgA antibodies in a population-based sample. EBV VCA-IgG and IgA antibodies were determined by ELISA in 272 controls (90% women, 26% African-American) selected to reflect the sex- and age-distribution of lupus cases in a 60 county area of the southeastern U.S. Occupational exposures estimated from lifetime job histories included pesticides, silica, solvents, sunlight, and shift-work. Analyses of VCA-IgA seroprevalence were limited to the 252 controls (93%) with VCA-IgG antibodies. Adjusted Odds Ratios (Adj. ORs) and 95% Confi- dence Intervals (CI) were estimated by logistic regression models including age, sex, race, and education. Results: Current smoking was significantly associated with VCA-IgA antibodies (Adj. OR = 4.2; 95% CI 2.1, 8.5). A moderate, but imprecise association was seen for occupational pesticide exposure (mixing or applying; Adj. OR = 2.7; 95% CI 0.7, 10.0), while UV exposure ( >/= 24 months of >/= 10 hrs per week working outside; Adj. OR = 1.5; 95% CI 0.7, 3.1) was modestly associated with VCA-IgA. Conclusions: These findings suggest that immune modulating environmental and occupational exposures may be related to control of latent EBVinfection, and should be considered in studies of EBV-related disease etiology.
American Journal of Epidemiology. Abstracts of the 2nd North American Congress of Epidemiology, June 21-24, 2006, Seattle, Washington