Abstract

An increased incidence of non-Hodgkin’s lymphoma (NHL) has been reported in farmers and other occupational groups working with pesticides. In these individuals, an increased prevalence of the chromosomal translocation t(14, 18)(q32, q21), one of the most common chromosomal abnormalities in NHL, has been detected in peripheral blood lymphocytes. This translocation juxtaposes the antiapoptotic BCL2 protein to the immunoglobulin heavy chain gene locus (IGH) leading to overexpression of BCL2. This causes an increase in cell survival, paving the way for malignant transformation. The present study aimed to evaluate the association between the occurrence of the chromosomal translocation t(14, 18) and occupational exposure to pesticides among a group of Jordanian farmers. A total of 192 male subjects including 96 agricultural workers and 96 control subjects participated in this study. BCL2-IGH t(14, 18) fusions were detected by a nested polymerase chain reaction (PCR) assay targeting the major breakpoint region (MBR). We found that occupational exposure to pesticides in open-field farming and insecticide used on animals increased the frequency of the chromosomal translocation t(14, 18). Farmers occupationally exposed to pesticides and insecticide were 13.5 times more likely to harbor t(14, 18). 63.5% (61 of 96) of farmers compared to 11.5% (11 of 96) of controls carried the translocation (odds ratio: 13.5, 95% confidence interval (CI) = 6.3–28.6). We ruled out the influence of possible confounding factors such as age, duration of sun exposure, alcohol intake, smoking, and use of personal protective equipment. Our results indicate that pesticides increased the frequency of chromosomal translocation in the 14q32 region. Accordingly, the presented data agrees with previous suggestions from the literature that pesticides might be involved in the development of NHL through the t(14, 18) pathway.