In the event of a radiological incident, a fast and accurate biological dosimetry (biodosimetry) method for evaluating people who have been potentially exposed to ionising radiation is crucial. Among the many biodosimetry methods available, the immunodetection of phosphorylated H2AX (γ-H2AX) stands as a promising method to be used in the triage of patients exposed to radiation. Currently, the most common way to measure γ-H2AX levels is through fluorescence microscopy. In this pilot study, we assessed the feasibility of using an enzyme-linked immunosorbent assay (ELISA) for quantifying γ-H2AX for biodosimetry purposes. Moreover, the usefulness of measuring phosphorylated ATM (pATM) levels through ELISA for biodosimetry was also evaluated. Blood samples were obtained from three male donors (38 y) and were irradiated with 60Co (0, 1, 2 and 6 Gy). Peripheral blood mononuclear cells (PBMCs) were isolated and lysed before measuring γ-H2AX, total H2AX protein and pATM using ELISA kits. The dicentric chromosome assay (DCA) using whole blood was also performed for comparison. Data from all donors at each dose were pooled before statistical analysis. The ratio of γ-H2AX/total H2AX and pATM levels increased in a radiation-dose-dependent manner. The average γ-H2AX/total H2AX ratios were 0.816 ± 0.219, 0.830 ± 0.685, 1.276 ± 1.151 and 1.606 ± 1.098, whereas the average levels of pATM were 59.359 ± 3.740, 63.366 ± 0.840, 66.273 ± 2.603 and 69.936 ± 4.439, in PBMCs exposed to 0, 1, 2 and 6 Gy, respectively. The linear-quadratic dose-response calibration curve for DCA was Y = 0.0017 (±0.0010) + 0.0251 (±0.0142) × D + 0.0342 (±0.0039) × D2 $\boldsymbol{Y}=\mathbf{0.0017}\left(\pm \mathbf{0.0010}\right)+\mathbf{0.0208}\left(\pm \mathbf{0.0218}\right)\times \boldsymbol{D}+\mathbf{0.0350}\left(\pm \mathbf{0.0050}\right)\times{\boldsymbol{D}}^{\mathbf{2}}$. Overall, despite a large variability in the ratio of γ-H2AX/total H2AX among donors, the present study revealed the suitability of using the ratio of γ-H2AX/total H2AX and pATM for biodosimetry. Still, more research with a larger group of subjects is necessary to construct a reliable calibration curve for the ratio of γ-H2AX/total H2AX and pATM levels for biodosimetry.

中文翻译：

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γ-H2AX 和磷酸 ATM 酶联免疫吸附测定作为辐射暴露评估的生物剂量测定方法：一项试点研究。

在发生放射事件时，快速准确的生物剂量测定（生物剂量测定）方法对于评估可能接触电离辐射的人员至关重要。在众多可用的生物剂量测定方法中，磷酸化 H2AX (γ-H2AX) 的免疫检测是一种有前景的方法，可用于对辐射患者进行分类。目前，测量 γ-H2AX 水平最常见的方法是通过荧光显微镜。在这项初步研究中，我们评估了使用酶联免疫吸附测定 (ELISA) 定量 γ-H2AX 进行生物剂量测定的可行性。此外，还评估了通过 ELISA 测量磷酸化 ATM (pATM) 水平在生物剂量测定中的有用性。血液样本取自三名男性捐献者（38 岁），并用 60Co（0、1、2 和 6 Gy）进行辐照。分离并裂解外周血单核细胞 (PBMC)，然后使用 ELISA 试剂盒测量 γ-H2AX、总 H2AX 蛋白和 pATM。还进行了使用全血的双着丝粒染色体测定（DCA）进行比较。在统计分析之前，汇集所有捐赠者在每个剂量下的数据。γ-H2AX/总 H2AX 和 pATM 水平的比率以辐射剂量依赖性方式增加。γ-H2AX/总 H2AX 的平均比率为 0.816 ± 0.219、0.830 ± 0.685、1.276 ± 1.151 和 1.606 ± 1.098，而 pATM 的平均水平为 59.359 ± 3.740、63.366 ± 0.840、66.273 ± 2 .603 和 69.936 ± 4.439，英寸PBMC 分别暴露于 0、1、2 和 6 Gy。DCA 的线性二次剂量反应校准曲线为 Y = 0.0017 (±0.0010) + 0.0251 (±0.0142) × D + 0.0342 (±0.0039) × D2 $\boldsymbol{Y}=\mathbf{0.0017}\left( \pm \mathbf{0.0010}\right)+\mathbf{0.0208}\left(\pm \mathbf{0.0218}\right)\times \boldsymbol{D}+\mathbf{0.0350}\left(\pm \mathbf{ 0.0050}\right)\times{\boldsymbol{D}}^{\mathbf{2}}$。总体而言，尽管供体之间 γ-H2AX/总 H2AX 的比率存在很大差异，但本研究揭示了使用 γ-H2AX/总 H2AX 和 pATM 的比率进行生物剂量测定的适用性。尽管如此，仍需要对更多受试者进行更多研究，以构建用于生物剂量测定的 γ-H2AX/总 H2AX 和 pATM 水平的可靠校准曲线。