AVALIAÇÃO DAS PROPORÇÕES DE CÉLULAS T, B, NK E NK/T EMINDIVÍDUOS EXPOSTOS À RADIAÇÃO IONIZANTE DE 137Cs
Introduction: Biological changes that result from exposure to ionizing radiation (IR)involving the immune system (IS), still need some elucidation. Radiological accidents,like the one in Chernobyl in Ukraine, Three Mile Island in the United States and theaccident with 137Cs in Brazil were some experiences that allow us to evaluate thestochastic effects of the exposure to the ionizing radiation, besides understandingimportant immediate somatic effects, like Radiation Acute Syndrome (RAS). The humanbody is constituted by about 5x1012 cells, and a number of them are highly specialized inthe development of their function in human physiology. Considering the ionizing radiationeffects on lymphocytes and their proteins, and the IS capacity to react in the face of suchexposures, there has been an investigation into the proportions of cells T, B, NK andNK/T in 13 radio-casualties, coming from groups I and II according to the degree ofexposure to 137Cs (SuLeide general protocol), in the September 13th 1987 accident inGoiânia. Objective: The study of lymphocyte cell populations T, B, NK and NK/T gives usthe oportunity to investigate possible alterations in the immune system of the people whohave been exposed to the IR of 137Cs. Methodology: For an evaluation of cellproportions, individuals exposed to IR were submitted to a vein puncture, after avoluntary agreement, so as to collect 5 ml of peripheral blood. As methodology, the fluxcellmeter, triple checking, via use of monoclonal antibodies anti-CD3/PercP, anti-CD4/FITC, anti-CD8/PE, anti-CD19/FITC, anti-CD5/PE and anti-CD56/PE. Results: thenumbers that were obtained from the cell populations and sub-populations of theindividuals exposed to the IR of 137Cs and normal controls did not show any statisticallymeaningful difference, although was observed a little decrease of the total NK cellpopulation, which is differently observed in the isolated evaluation of the NK and NK/T sub-populations, that showed statistically equivalent to the numbers found in normalcontrols. Conclusion: However, the outcome observed in this investigation suggested apossible IR influence upon these individuals? cellular proportions. Additional experimentsare now in development in order to evaluate the functional activity of cells NK and NK/Tof the radio-casualties.
Advisor:Aparecido Divino da Cruz
School:Universidade Católica de Goiás
Source Type:Master's Thesis
Date of Publication:11/30/2006