Page 337 - 2014 Printable Abstract Book
P. 337
is distinct for different exposures (radiation, sepsis, and trauma) will increase the specificity of the
radiation signature and can be the basis of rapid and reliable countermeasures in humans.
(PS6-21) High-throughput, reverse transcription qPCR method using gene expression biomarkers
determined from whole blood for estimating absorbed dose of ionizing radiation. Joshua LaBaer, MD,
PhD; Garrick L. Wallstrom, PhD; Kristin A. Gillis; Jin Park, PhD; Velu Murugan, PhD; D. M. Magee, PhD; and
Michael N. Gaskin, VG Piper Center for Personalized Diagnostics, Biodesign Institute, Arizona State
University, Tempe, AZ
There are several efforts underway to provide measurement systems capable of quantifying
absorbed dose of radiation in the event of an unexpected acute exposure to ionizing radiation. Gene
expression signatures using human peripheral blood have been shown to predict absorbed radiation
doses in previous studies. In this study, we use non-human primate (NHP) gene expression responses and
compare to those in human patients undergoing radiation therapy to identify human genes that respond
quantitatively to radiation. A rigorous gene selection process was developed with early screening of
potential confounding factors to radiation response. With determination of these gene biomarkers, an
algorithm is developed to estimate absorbed dose from blood samples collected several days following
exposure. Our Biodosimetry Test is based on a reverse transcription quantitative polymerase chain
reaction (qPCR) system intended for quantitative in vitro diagnostic (IVD) estimation of total body
absorbed dose of ionizing radiation over a range of 0-10 Gy over 7 days as measured in a general, adult
population. Whole blood sample mRNA is collected and stabilized inside vacutainers for analysis of gene
biomarkers. Optimized chemistry and automation have obviated the need for RNA isolation and
purification. From experimental lymphocyte depletion kinetics, it is estimated that for a 100 µL sample of
irradiated, RNA-stabilized blood, the analytical method must be able to quantify gene expression based
on an approximate range of 1E+03 to 3E+06 lymphocytes (~ 2 ng to 5 μg RNA), requiring high sensitivity
and dynamic range of the analytical instrumentation. Our Biodosimetry Test results show high
performance for estimating dose that supports the gene expression application on a high-throughput
qPCR platform and the use of the in vivo NHP models developed for this application.
This paper describes the test models and analytical system developed for HT measurement of total
absorbed dose of radiation from peripheral blood samples. Our Biodosimetry Test is intended to be
conducted in a clinical laboratory and information used as an adjunct with other clinical considerations to
aid a medical professional in assessing the need for treatment in the event of a radiological public health
emergency or unplanned exposure to ionizing radiation.
(PS6-22) Transcript analysis for characterizing internal biodosimetry using peripheral blood from
1
patients with neuroblastoma treated with 131I-mIBG targeted radiotherapy. David A. Edmondson, MS ;
1
2
3
1
Erin E. Karski, MD ; Ayano Kohlgruber, BS ; Harsha Koneru, BS ; Leif Peterson, Ph.D ; Katherine Matthay,
2
2
1;4
MD ; Steven DuBois, MD ; and Matthew Coleman, Ph.D ; Lawrence Livermore National Laboratory,
1
2
Livermore, CA ; University of California San Francisco School of Medicine, San Francisco, CA ; Houston
Methodist Research Institute, Houston, TX ; and University of California Davis, Davis, CA
4
3
Internal dosimetry is difficult and relies on estimates using MIRD or ICRP biokinetic models. To
address this, we looked at gene expression analysis in whole blood from patients receiving targeted
335 | P a g e
radiation signature and can be the basis of rapid and reliable countermeasures in humans.
(PS6-21) High-throughput, reverse transcription qPCR method using gene expression biomarkers
determined from whole blood for estimating absorbed dose of ionizing radiation. Joshua LaBaer, MD,
PhD; Garrick L. Wallstrom, PhD; Kristin A. Gillis; Jin Park, PhD; Velu Murugan, PhD; D. M. Magee, PhD; and
Michael N. Gaskin, VG Piper Center for Personalized Diagnostics, Biodesign Institute, Arizona State
University, Tempe, AZ
There are several efforts underway to provide measurement systems capable of quantifying
absorbed dose of radiation in the event of an unexpected acute exposure to ionizing radiation. Gene
expression signatures using human peripheral blood have been shown to predict absorbed radiation
doses in previous studies. In this study, we use non-human primate (NHP) gene expression responses and
compare to those in human patients undergoing radiation therapy to identify human genes that respond
quantitatively to radiation. A rigorous gene selection process was developed with early screening of
potential confounding factors to radiation response. With determination of these gene biomarkers, an
algorithm is developed to estimate absorbed dose from blood samples collected several days following
exposure. Our Biodosimetry Test is based on a reverse transcription quantitative polymerase chain
reaction (qPCR) system intended for quantitative in vitro diagnostic (IVD) estimation of total body
absorbed dose of ionizing radiation over a range of 0-10 Gy over 7 days as measured in a general, adult
population. Whole blood sample mRNA is collected and stabilized inside vacutainers for analysis of gene
biomarkers. Optimized chemistry and automation have obviated the need for RNA isolation and
purification. From experimental lymphocyte depletion kinetics, it is estimated that for a 100 µL sample of
irradiated, RNA-stabilized blood, the analytical method must be able to quantify gene expression based
on an approximate range of 1E+03 to 3E+06 lymphocytes (~ 2 ng to 5 μg RNA), requiring high sensitivity
and dynamic range of the analytical instrumentation. Our Biodosimetry Test results show high
performance for estimating dose that supports the gene expression application on a high-throughput
qPCR platform and the use of the in vivo NHP models developed for this application.
This paper describes the test models and analytical system developed for HT measurement of total
absorbed dose of radiation from peripheral blood samples. Our Biodosimetry Test is intended to be
conducted in a clinical laboratory and information used as an adjunct with other clinical considerations to
aid a medical professional in assessing the need for treatment in the event of a radiological public health
emergency or unplanned exposure to ionizing radiation.
(PS6-22) Transcript analysis for characterizing internal biodosimetry using peripheral blood from
1
patients with neuroblastoma treated with 131I-mIBG targeted radiotherapy. David A. Edmondson, MS ;
1
2
3
1
Erin E. Karski, MD ; Ayano Kohlgruber, BS ; Harsha Koneru, BS ; Leif Peterson, Ph.D ; Katherine Matthay,
2
2
1;4
MD ; Steven DuBois, MD ; and Matthew Coleman, Ph.D ; Lawrence Livermore National Laboratory,
1
2
Livermore, CA ; University of California San Francisco School of Medicine, San Francisco, CA ; Houston
Methodist Research Institute, Houston, TX ; and University of California Davis, Davis, CA
4
3
Internal dosimetry is difficult and relies on estimates using MIRD or ICRP biokinetic models. To
address this, we looked at gene expression analysis in whole blood from patients receiving targeted
335 | P a g e
