Cytokinesis block micronucleus in human lymphocytes: Effect of low dose radiation in vascular radiology

This paper studies the frequency of occurrence of micronuclei (MN) in irradiated patients' lymphocytes during medical radiodiagnostic examinations by cytogenetic block (CB) technique. Firstly, dose-response curves have been obtained in order to determine MN occurrence in peripheral blood lymphocytes in nine healthy patients in connection with the radiation doses administered. Subsequently, total blood samples of 25 patients having undergone any complex radiological procedure have been analysed. Four different blood samples have been collected from those patients as follows: 1) prior to irradiation, corresponding to a non-irradiated control sample; 2) prior to irradiation, to which the radiological contrast was added at a concentration of 5%; 3) sample obtained at the beginning of the examination but remaining in vitro, exposed to the primary irradiation beam throughout the radiological exploration; 4) sample obtained from the patient at the end of the radiological procedure. Results show that MN frequency in lymphocytes with cytogenetic block and the ionizing radiation dose administered are interdependent. A significant increase of MN in patients' samples obtained after radiological examinations (irradiated samples) compared to those obtained before examinations (control samples) (p<0,01) has been observed. The radiological contrast medium has not produced significant changes in MN induction to the concentration used in this study. The micronucleus assay (CB) is simple and could be applied in situations where physical dosimetry is not possible. It could be used to assess individual sensitivity to radiation and to determine exposures to low doses of irradiation if a previous comparative pattern were available for the exposed worker or patient. (author)