Establishment and validation of surface model for biodosimetry based on γ-H2AX foci detection.

Publisher: Taylor & Francis Country of Publication: England NLM ID: 8809243 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1362-3095 (Electronic) Linking ISSN: 09553002 NLM ISO Abbreviation: Int J Radiat Biol Subsets: MEDLINE

Original Publication: London ; New York : Taylor & Francis, [c1988-

Histones* ; Radioactive Hazard Release*; Calibration ; Cell Nucleus ; Dose-Response Relationship, Radiation ; Lymphocytes/radiation effects

Introduction: In the event of a radiation accident detecting γ-H2AX foci is being accepted as fast method for triage and dose assessment. However, due to their disappearance kinetics, published calibrations have been constructed at specific post-irradiation times.
Objectives: To develop a surface, or tridimensional, model to estimate doses at times not included in the calibration analysis, and to validate it.
Materials and Methods: Calibration data was obtained irradiating peripheral mononucleated cells from one donor with radiation doses ranging from 0 to 3 Gy, and γ -H2AX foci were detected microscopically using a semi-automatic method, at different post-irradiation times from 0.5 to 24 h. For validation, in addition to the above-mentioned donor, blood samples from another donor were also used. Validation was done within the range of doses and post-irradiation times used in the calibration.
Results: The calibration data clearly shows that at each analyzed time, the γ-H2AX foci frequency increases as dose increases, and for each dose this frequency decreases with post-irradiation time. The γ-H2AX foci nucleus distribution was clearly overdispersed, for this reason to obtain bidimensional and tridimensional dose-effect relationships no probability distribution was assumed, and linear and non-linear least squares weighted regression was used. In the two validation exercises for most evaluated samples, the 95% confidence limits of the estimated dose were between ±0.5 Gy of the real dose. No major differences were observed between donors.
Conclusion: In case of a suspected overexposure to radiation, the surface model here presented allows a correct dose estimation using γ-H2AX foci as biomarker. The advantage of this surface model is that it can be used at any post-irradiation time, in our model between 0.5 and 24 h.

Keywords: biodosimetry*; ionizing radiation*; surface model*; γ-H2AX*

0 (Histones)

Date Created: 20211027 Date Completed: 20220411 Latest Revision: 20220429

20231215

10.1080/09553002.2022.1998706

34705602