DosiKit, a New Portable Immunoassay for Fast External Irradiation Biodosimetry.

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.

Integration of new biological and physical retrospective dosimetry methods into EU emergency response plans - joint RENEB and EURADOS inter-laboratory comparisons.

PURPOSE: RENEB, 'Realising the European Network of Biodosimetry and Physical Retrospective Dosimetry,' is a network for research and emergency response mutual assistance in biodosimetry within the EU. Within this extremely active network, a number of new dosimetry methods have recently been proposed or developed. There is a requirement to test and/or validate these candidate techniques and inter-comparison exercises are a well-established method for such validation. MATERIALS AND METHODS: The authors present details of inter-comparisons of four such new methods: dicentric chromosome analysis including telomere and centromere staining; the gene expression assay carried out in whole blood; Raman spectroscopy on blood lymphocytes, and detection of radiation-induced thermoluminescent signals in glass screens taken from mobile phones. RESULTS: In general the results show good agreement between the laboratories and methods within the expected levels of uncertainty, and thus demonstrate that there is a lot of potential for each of the candidate techniques. CONCLUSIONS: Further work is required before the new methods can be included within the suite of reliable dosimetry methods for use by RENEB partners and others in routine and emergency response scenarios.

Revisiting Biomarkers of Total-Body and Partial-Body Exposure in a Baboon Model of Irradiation.

In case of a mass casualty radiation event, there is a need to distinguish total-body irradiation (TBI) and partial-body irradiation (PBI) to concentrate overwhelmed medical resources to the individuals that would develop an acute radiation syndrome (ARS) and need hematologic support (i.e., mostly TBI victims). To improve the identification and medical care of TBI versus PBI individuals, reliable biomarkers of exposure could be very useful. To investigate this issue, pairs of baboons (n = 18) were exposed to different situations of TBI and PBI corresponding to an equivalent of either 5 Gy 60Co gamma irradiation (5 Gy TBI; 7.5 Gy left hemibody/2.5 right hemibody TBI; 5.55 Gy 90% PBI; 6.25 Gy 80% PBI; 10 Gy 50% PBI, 15 Gy 30% PBI) or 2.5 Gy (2.5 Gy TBI; 5 Gy 50% PBI). More than fifty parameters were evaluated before and after irradiation at several time points up to 200 days. A partial least square discriminant analysis showed a good distinction of TBI from PBI situations that were equivalent to 5 Gy. Furthermore, all the animals were pooled in two groups, TBI (n = 6) and PBI (n = 12), for comparison using a logistic regression and a non parametric statistical test. Nine plasmatic biochemical markers and most of hematological parameters turned out to discriminate between TBI and PBI animals during the prodromal phase and the manifest illness phase. The most significant biomarkers were aspartate aminotransferase, creatine kinase, lactico dehydrogenase, urea, Flt3-ligand, iron, C-reactive protein, absolute neutrophil count and neutrophil-to-lymphocyte ratio for the early period, and Flt3-ligand, iron, platelet count, hemoglobin, monocyte count, absolute neutrophil count and neutrophil-to-lymphocyte ratio for the ARS phase. These results suggest that heterogeneity could be distinguished within a range of 2.5 to 5 Gy TBI.

Atlas of genetics and cytogenetics in oncology and haematology in 2013.

The Atlas of Genetics and Cytogenetics in Oncology and Haematology (http://AtlasGeneticsOncology.org) is a peer-reviewed internet journal/encyclopaedia/database focused on genes implicated in cancer, cytogenetics and clinical entities in cancer and cancer-prone hereditary diseases. The main goal of the Atlas is to provide review articles that describe complementary topics, namely, genes, genetic abnormalities, histopathology, clinical diagnoses and a large iconography. This description, which was historically based on karyotypic abnormalities and in situ hybridization (fluorescence in situ hybridization) techniques, now benefits from comparative genomic hybridization and massive sequencing, uncovering a tremendous amount of genetic rearrangements. As the Atlas combines different types of information (genes, genetic abnormalities, histopathology, clinical diagnoses and external links), its content is currently unique. The Atlas is a cognitive tool for fundamental and clinical research and has developed into an encyclopaedic work. In clinical practice, it contributes to the cytogenetic diagnosis and may guide treatment decision making, particularly regarding rare diseases (because they are numerous and are frequently encountered). Readers as well as the authors of the Atlas are researchers and/or clinicians.

Characterization of quantitative chromosomal abnormalities in renal cell carcinomas by interphase four-color fluorescence in situ hybridization.

Renal cell carcinomas (RCC) in adults are histologically heterogeneous solid tumors with specific chromosomal abnormality patterns included in the World Health Organization (WHO) classification. To overcome some of the drawbacks of cytogenetic and comparative genomic hybridization (CGH) analyses, we designed a first-generation cytogenetic diagnostic test using four-color fluorescence in situ hybridization (FISH) on interphase nuclei. We selected 51 bacterial artificial chromosome and P1-derived artificial chromosome clones covering 17 chromosomal regions involved in the abnormalities of the adult RCC histologic subtypes. An initial set of probes allowed the identification of clear-cell RCC, papillary RCC, and other RCC on a single slide. A second test allowed the detection of additional chromosomal abnormalities or aberrations specific to chromophobic RCC and oncocytomas. We tested 25 cases of RCC, and the results were in agreement with those of cytogenetic techniques and/or CGH methods. The techniques appeared to be very sensitive, because small tumoral cell clones that were undetected by other cytogenetic methods were identified with this method. It was concluded that the multicolor FISH test was specific and sensitive, easy to perform, and could be part of the investigation process in RCC.