Development of a point-of-care radiation biodosimeter: studies using novel protein biomarker panels in non-human primates

Abstract

Purpose: There is a need to rapidly triage individuals for absorbed radiation dose following a significant nuclear event. Since most exposed individuals will not have physical dosimeters, we are developing a method to assess exposure dose based on the analysis of a specific panel of blood proteins that can be easily obtained from a fingerstick blood sample.

Materials and methods: In three large non-human primate (NHP) studies, animals were exposed to single acute total body doses of x-ray or gamma radiation. A total of 895 blood samples were obtained at baseline and for 7 days after exposure, to evaluate the temporal progression of markers in each of 10 animals (5M/5F) in six dose groups receiving 0–10 Gy. We used tandem mass spectrometry and immunoassay techniques to identify radiation-responsive proteins in blood plasma samples.

Results: A blood protein biomarker panel was developed based on analysis of blood plasma samples obtained from several irradiation studies in NHPs that aimed to simulate acute radiation injury in humans from a nuclear exposure event. Panels of several subsets of proteins were shown to accurately classify plasma samples into two exposure groups either above or below a critical dose threshold with sensitivities and specificities exceeding 90%.

Conclusion: This study lays the groundwork for developing a radiation biodosimetry triage tool. Our results in NHPs must be compared with those in human patients undergoing radiotherapy to determine if the biomarker panel proteins exhibit a similar radiation response and allow adequate classification power in humans.

Keywords:

• Radiation biodosimetry
• blood biomarkers
• NHP irradiation studies
• immunoassays
• mass spectroscopy

Note

Disclosure statement

The authors have no financial and/or business interest that may be affected by the research reported in this article.

Notes

1 In this article, we refer to NHP (Macaca mulatta) alpha amylase simply as AMY. In the most recent rhesus genome annotation (released in December 2015), there are two alpha amylase genes. They are both located on Chromosome 1 and separated from each other by ∼144 kb. The current annotation gives these genes the names of AMY2B and LOC713027 (previously known as isoform 4). Both are (probably inappropriately at this point) described as pancreatic alpha amylase. Using tandem MS, we identified these two alpha amylase isoforms in the saliva of NHPs, isoform 2B and isoform 4, both of which were found to be radiation responsive. Our assays use custom antibodies developed to detect these two isoforms.

Additional information

Funding

This work was funded in whole or in part with Federal funds from the Biomedical Advanced Research and Development Authority (BARDA), Office of the Assistant Secretary for Preparedness and Response, Office of the Secretary, Department of Health and Human Services, under Contract No. HHSO10020100007C to SRI International.

Notes on contributors

Robert P. Balog

Robert P. Balog received his PhD in Biomedical Engineering from the University of Texas Southwestern Medical Center at Dallas in 2003 and has worked in the area of molecular diagnostics since 2003. Dr. Balog served as a Co-PI for this work.

Polly Chang

Polly Chang received her PhD in Biophysics from the University of California, Berkeley and has worked in the area of radiation biology as well as drug development since 1990. Dr. Chang served as a Co-PI for this work.

Harold S. Javitz

Harold S. Javitz received his PhD in Statistics from the University of California at Berkeley. He is a senior statistician at SRI International. His research interests include smoking cessation, biostatistics and educational studies.

Shirley Lee

Shirley Lee received her MS in Computer Science from Indiana University and has worked in the area of bioinformatics and computational and statistical analysis methods.

Hua Lin

Hua Lin holds PhD in Physical Chemistry from Fudan University, China and was a postdoctoral fellow at UC Davis. Dr. Lin has 20 years experience in high-throughput proteomics and has led numerous biomarker characterization projects using a wide range of quantitative proteomics, metabolomics, and peptidomics methods.

Thomas Shaler

Thomas Shaler received his PhD in Organic Chemistry from the UC Riverside and was a postdoctoral fellow at SRI. He has deep experience in a wide variety of areas related to biological mass spectrometry using novel assays and strategies for biomarker discovery and quantitative proteomics.

David E. Cooper

David E. Cooper received his PhD in Physics from MIT in 1980 and has worked in the area of medical devices, biosensors, and molecular diagnostics since 1996. Dr. Cooper served as the PI for this work.