In the event of nuclear meltdown or improvised nuclear bomb, presumed victims of radiation exposure would overwhelm emergency responders and hospitals. Victims can’t smell or see radiation around them, and low-level exposure doesn’t result in obvious bodily injury. The likely outcome: long lines of patients with no visual symptoms, panicked and difficult to assess.
Duke University researchers are developing a blood test that can tell in just hours how much radiation a person has absorbed from a nuclear incident. During a large-scale emergency such as the meltdown at the Japanese Fukushima Daiichi reactors in 2011, faster testing could give doctors and patients clarity about the extent of exposures and which victims need medical care.
This month, the Biomedical Advanced Research and Development Authority (BARDA), a division of the U.S. Department of Health and Human Services, awarded Duke an additional $10.4 million contract to continue the program through early 2016, bringing total funding since 2009 to more than $43 million.
The multi-gene test, called a biodosimeter, comprises the work of scientists under the leadership of Dr. Nelson Chao, M.D., M.B.A., at Duke University; Dr. Frederic Zenhausern, Ph.D., M.B.A., at the University of Arizona; and scientists at Thermo Fisher Scientific and DxTerity Diagnostics. DxTerity representatives said they expect to take the biodosimeter to the Food and Drug Administration for approved medical use within the next three years.
The project builds on almost a decade of study at Duke of the human response to ionizing radiation, said Gary Phillips, Duke’s BARDA program manager.
The key to the test lies in a gene signature that indicates radiation absorption in the body. Researchers Dr. Holly Dressman, Ph.D., Dr. Joseph E. Lucas, Ph.D., and John Chute, M.D., at the Duke Cancer Institute first detected this gene signature in 2007 while comparing blood-based gene expression in healthy patients to patients who had undergone full-body radiation.
In 2009, Duke partnered with DxTerity and the University of Arizona to develop a high throughput radiation exposure system, a process that uses robotics and other automation to run large-scale experiments in a relatively short amount of time. The system uses a genomic testing platform from DxTerity that can use a blood sample to detect the radiation gene signature. DxTerity’s direct-from-blood test eliminates the need to first isolate RNA from the blood sample, saving time and money.
“If cleared, the radiation absorption test would be the first direct-from-blood, multiplex gene expression test approved by the FDA, and would open the door for other direct-from-blood gene assays,” said Bob Terbrueggen, founder and CEO of DxTerity. The company designed the technology to allow labs around the world to run other direct-from-blood tests on existing infrastructure and at a relatively low cost.
If the radiation test is cleared by the FDA, approved labs across the country would be trained to use the technology and government agencies could potentially stockpile test kits for emergencies.
Duke’s gene signature research and the DxTerity genomic testing system have other potential applications in clinical medicine. They could provide a method to evaluate a cancer patient’s tolerance for radiation treatment and to predict radiation-induced side effects in various types of cancers. The DxTerity platform is also being used to develop low-cost tests for rheumatoid arthritis and even flu detection.
In the near future, gene expression-based testing could also spot early indicators of heart conditions or liver cancer.
With the creation of the biodosimeter test and associated technologies, adapting it to other applications would be a matter of simply “rekeying a lock,” Phillips said.