DosiKit is a new field-radiation biodosimetry immunoassay for rapid triage of individuals exposed to external total-body irradiation. Here, we report on the validation of this immunoassay in human blood cell extracts 0.5 h after in vitro exposure to 137Cs gamma rays, using γ-H2AX analysis. First, calibration curves were established for five donors at doses ranging from 0 to 10 Gy and dose rates ranging from ∼0.8 to ∼3 Gy/min. The calibration curves, together with a γ-H2AX peptide scale, enabled the definition of inter-experimental correction factors. Using previously calculated correction factors, blind dose estimations were performed at 0.5 h postirradiation, and DosiKit performance was compared against concomitant dicentric chromosome assay (DCA), the current gold standard for external irradiation biodosimetry. A prototype was then assembled and field tested. We show that, despite significant inter-individual variations, DosiKit can estimate total-body irradiation doses from 0.5 to 10 Gy with a strong linear dose-dependent signal and can be used to classify potentially exposed individuals into three dose ranges: below 2 Gy, between 2 and 5 Gy and above 5 Gy. The entire protocol can be performed in 45 min, from sampling to dose estimation, with a new patient triaged every 10 min. While DCA enables precise measurement of doses below 5 Gy, it is a long and difficult method. In contrast, DosiKit is a quick test that can be performed directly in the field by operational staff with minimal training, and is relevant for early field triage and identification of individuals most likely to experience acute radiation syndrome. These findings suggest that DosiKit and DCA are complementary and should be combined for triage in a mass scale event. While the proof-of-concept reported here validates the use of DosiKit at 0.5 h postirradiation, further studies are needed to calibrate and evaluate the performance of the DosiKit assay at longer times after irradiation.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 190 • No. 2