Translocation t(14;18) in healthy individuals: Preliminary study of its association with family history and agricultural exposure

Background. The t(14;18) translocation, present in 90% of follicular non-Ho dgkin's lymphomas (NHL). has been found to exist in low levels in healthy p ersons. Its clinical/prognostic significance in healthy populations is unkn own. and risk factors for its development have not been determined. Our obj ectives were to assess the prevalence of t(14:18) in individuals without NH L, comparing residents of agricultural settlements (kibbutzim) with city dw ellers, as well as first degree relatives of NHL cases. Patients and methods. Residents of kibbutzim and members of two control gro ups: 1) Jerusalem residents - randomly selected hospital administrative wor kers and 2) first degree Family members of lymphoma patients were interview ed extensively regarding exposures and had blood drawn for t(14:18) determi nation. The translocation was detected after B-cell purification of blood s amples with CD-19 microbeads (Mini-Macs(TM)) using nested PCR. The method d etects the translocation in a BCL2 positive cell line after dilutions of up to 1 : 10(5) with normal peripheral blood lymphocytes. Results. Nineteen of two hundred thirty healthy individuals (8.3%) tested w ere found to he positive for t(14;18). No statistically significant differe nces in the prevalence of t(14;18) were detected among the rural and urban populations. Five of thirty-four (11.9%) family members tested positive for t(14:18). No age or sex differences between t(14:18) positive and negative individuals were found. No significant association with exposure to specif ic agricultural or other chemicals was found. Conclusions: The presence of the t(14;18) translocation in healthy individu als was not associated with agricultural residence in this preliminary stud y. Whether relatives of patients with NHL are at increased risk will requir e further study in larger populations. Specific exposures affecting the ons et of this translocation have not been ruled out. The significance of this translocation in healthy individuals remains unknown.