The second gamma-H2AX assay inter-comparison exercise carried out in the framework of the European biodosimetry network (RENEB)

Abstract

Purpose: Within the EU RENEB project, seven laboratories have taken part in training and harmonisation activities to strengthen triage gamma-H2AX-based radiation exposure assessment. This has culminated in a second triage biodosimetry exercise.

Materials and methods: Whole blood and separated lymphocyte samples were homogenously irradiated with ⁶⁰Co gamma rays at 0.5, 2.5 (blind samples), 0 and 2 Gy (reference samples). Following post-exposure incubations of 4 and 24 h, 16 samples were shipped on ice packs to each partner. The samples were stained and scored for gamma-H2AX foci, using manual and/or automated fluorescence microscope scoring strategies. Dose estimates were obtained and used to assign triage categories to the samples.

Results: Average dose estimates across all the laboratories correlated well with true doses. The most accurate assignment of triage category was achieved by manual scoring of the 4-h blood and lymphocyte samples. Only three samples out of a total of 46 were miscategorized in a way that could have adversely effected the clinical management of a radiation casualty.

Conclusions: This inter-comparison exercise has demonstrated that following a recent acute radiation exposure, the gamma-H2AX assay could be a useful triage tool that can be successfully applied across a network of laboratories.

Keywords:

• RENEB
• triage
• biological dosimetry
• gamma-H2AX assay
• radiation-induced foci

Acknowledgements

The authors wish to thank R. Sokolowski of the Medical Research Council, Harwell, UK, for performing the ⁶⁰Co gamma irradiation and Mark Hill and James Thompson, of the Gray Institute for Radiation Oncology and Biology, Oxford, UK, for the dosimetry.

Disclosure statement

The authors report no conflicts of interest.