AVALIAÇÃO DA TRANSLOCAÇÃO T(14;18) MBR EM INDIVÍDUOS EXPOSTOS A BAIXAS DOSES DE RADIAÇÃO DE 137CsCl EM GOIÂNIA, GOIÁS, BRASIL

Abstract

Healthy radio-exposed individuals, who received low levels of Cesium-137 radiation, during the accident that happened in Goiania, in 1987 and their familiars were tested for the detection of t(14;18) rearranged B cells in peripheral blood, using a high sensitive real-time quantitative PCR method. Also were tested a control group comprised of healthy non exposed age matched men. The chromosomal translocation t(14;18)(q32;q21) is characteristic of Follicular Lymphoma and it is a frequent abnormality in other types of non-Hodgkin lymphoma. This translocation leads to constitutive activation of the BCL2 oncogene by the enhancers of the immunoglobulin heavy chain loco. T(14;18) translocation constitute the genetic hallmark and early initiating event of Follicular Lymphoma. In healthy individuals, the same translocation may also be found in a small fraction of peripheral blood lymphocytes and positive cells might serve as an indicator for environmental exposure to carcinogens and possibly correlate with the cumulative risk of developing t(14;18)-positive non-Hodgkin lymphoma. Eight healthy radio-exposed, five relatives including three children, and four not exposed healthy men were tested for the detection of this translocation. Only one unexposed individual from the control group was positive for the chromosomal translocation, healthy radio-exposed individuals presented lower levels of cells bearing the BCL-2/JH rearrangement when compared to the levels of the patients with Follicular Lymphoma before treatment, however, test more cells would be required to confirm the total absence of circulating cells bearing the rearrangement BCL2/JH.