A rapid increase in the incidence of non-Hodgkin lymphoma (NHL) has been reported in many countries. Exposure to certain pesticides or organochlorines has been shown to be a risk factor. Epstein-Barr virus (EBV) is a human herpesvirus that has been associated with some subgroups of NHL, such as Burkitt lymphoma and lymphomas related to severe immunosuppression. In this study we measured concentrations of dioxins and dibenzofurans in 33 NHL cases and 39 surgical controls. For 23 of the cases and 32 of the controls EBV titers were also available. Median titer of antibodies to EBV early antigen (EA) IgG was higher in patients than in controls. Concentrations of dioxins and dibenzofurans were divided into two groups according to the median concentration for the controls. Unconditional logistic regression analysis was performed adjusting for sex, age, and body mass index. For several higher chlorinated congeners increased risk was found for patients in the high-concentration and high-titer group. For toxic equivalency factor >27.79 and EA>80 an odds ratio of 2.8 with 95% confidence interval 0.52-18 was calculated. These results indicated that current exposure to certain organochlorines in combination with EBV might increase the risk for NHL.
Copyright 2001 Academic Press.