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-Hodgkin's lymphomas (NHL). has been found to exist in low levels in healthy persons. Its clinical/prognostic significance in healthy populations is unknown. and risk factors for its development have not been determined. Our objectives were to assess the prevalence of t(14:18) in individuals without NHL, comparing residents of agricultural settlements (kibbutzim) with city dwellers, as well as first degree relatives of NHL cases. Patients and methods. Residents of kibbutzim and members of two control groups: 1) Jerusalem residents - randomly selected hospital administrative workers and 2) first degree Family members of lymphoma patients were interviewed extensively regarding exposures and had blood drawn for t(14:18) determination. The translocation was detected after B-cell purification of blood samples with CD-19 microbeads (Mini-Macs(TM)) using nested PCR. The method detects 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 were found to he positive for t(14;18). No statistically significant differences 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 specific agricultural or other chemicals was found. Conclusions: The presence of the t(14;18) translocation in healthy individuals was not associated with agricultural residence in this preliminary study. Whether relatives of patients with NHL are at increased risk will require further study in larger populations. Specific exposures affecting the onset of this translocation have not been ruled out. The significance of this translocation in healthy individuals remains unknown.