放射诊疗工作人员血型糖蛋白A基因突变频率及其相关因素的研究

目的 探讨血型糖蛋白A(GPA)基因突变频率用于辐射危险评价及预测电离辐射诱发肿瘤风险的可行性.方法 采用固定人群分层随机抽样的方法,选取上海市放射诊疗工作人员336例(按工种分为X射线影像诊断组、CT影像诊断组、介人放射学组和放射治疗组),健康对照组 112例；其中,经血型鉴定为MN杂合个体的放射诊疗工作人员为176例,健康对照者为58例.分离、固定、荧光免疫标记外周血红细胞后,应用流式细胞仪,按照BR6-1WI方法,分析GPA基因突变频率；采用胞质分裂阻断微核+3-氨基苯甲酰胺指数实验(CB微核+3AB指数实验),检测DNA损伤修复能力以反映研究对象的个体易感性.结果 放射诊疗工作人员GPA基因突变频率明显高于健康对照组(t=2.29～11.48,P＜0.05),尤其是介入放射学组的GPA NO基因突变频率明显高于X射线影像诊断组(t =2.01,P＜0.05).GPA NO基因突变频率受放射工龄、累积剂量和3AB指数的影响作用明显,而GPA NN基因突变频率仅受放射工龄影响,与累积剂量和3AB指数的相关性不明显.结论 对于职业低剂量电离辐射受照人群,GPA NO基因突变频率可较好地反映电离辐射诱发的DNA损伤效应和个体的辐射易感性,较GPA NN基因突变频率更适宜和敏感.

Glycophorin A mutation and relevant factors in medical radiation workers

Objective To explore the feasibility of using glycophorin A somatic mutation in peripheral erythrocytes,in order to evaluate the cancer risk of occupational medical exposure to ionizing radiation. Methods Totally 336 medical radiation workers were recruited as three groups (general radiation group, computer tomography group, intervention and radiation treatment group) and 112 healthy adults were selected as control by using stratified random cluster sampling method, where 176 medical-radiation workers and 58 health controls had a MN-heterozygous type. The erythrocytes were fixed and bound with fluorescent-labeled monoclonal antibody, and the glycophorin A somatic mutation frequency was assayed by a modified BR6-1W1 method using a FACScan flow cytometer. The individual susceptibility to radiation was investigated using micronuclei test and 3-Aminobenzamide index test. Results The GPA somatic mutation frequency of medical-radiation workers was significantly higher than that of healthy control (t=2.29-11.48,P<0.05). In particular, the NO GPA aberration frequency of interventional radiology workers was much higher than that of the general medical diagnostic workers (t = 2.01, P<0.05). In addition, the NO GPA variant frequency changed significantly with the years of radiation service, cumulative doses, and 3AB index. However, the NN GPA variant frequency was only associated with the years of radiation service, and no significant correlations were found between NN GPA variant frequency and cumulative dose of radiation exposure or 3AB index. Conclusions GPA mutation frequency, especially NO GPA mutation frequency could be used as a sensitive biomarker to predict the DNA damage and individual susceptibility for the population exposed to professional low-dose ionizing radiation.