A Non-traditional Approach to Diagnosis
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Despite continued advances in the field, a number of diseases still lack reliable diagnostic tests. Increased understanding and use of chemical information is one area that could help in the development of new and more effective diagnostic tests and devices.
Recent research published in Analytical Chemistry1 highlights a new method that probes chemical information to detect oxidative stress. To learn more about the role that oxidative stress measurements could play in disease diagnosis, and how new tools could help analyze chemical information such as this, we spoke to Dr. Gregory Payne, Professor, Institute for Bioscience and Biotechnology Research and Fischell Department of Bioengineering, University of Maryland.
Q. Can you tell us about your lab’s main research directions?
A. In my lifetime, I witnessed how electronics transformed our lives. Things that didn't exist when I was a child - computers and wireless communications - are routine now using devices that have become progressively smaller, cheaper, faster and easier to use. Yet these advances have had very limited impacts on the way we access and analyze chemical information. We still rely on a dog’s nose to provide critical information of a chemical nature. Over the last 5 years our lab has focused on trying to understand how the advances of the information age can be applied for accessing and analyzing chemical information.
We especially focus on probing for chemical information that is currently ill-defined – for instance information on oxidative stress. Oxidative stress is important as it plays a major role in a variety of chronic and degenerative diseases.
Q. What are some of the current limitations of diagnosing schizophrenia and related mental health disorders?
A. Schizophrenia is a complex disease with diagnosis and symptom evaluation relying on the expert assessment of clinicians. The problem is that this approach can be slow and often the disease has progressed to a point of rather severe symptoms. Earlier diagnosis would be beneficial as it is believed that a shorter Duration of Untreated Psychosis (DUP) is associated with greater response to antipsychotic treatment, while a longer DUP is associated with worse outcomes and a lower likelihood for achieving remission. In general blood or urine tests are currently not used to assist in evaluation because it is not clear what chemicals in these samples would provide useful information. Increasingly, researchers believe there is a link between schizophrenia and oxidative stress and thus our approach was to determine if we could probe the chemical information in serum samples to discover signatures of oxidative stress.
Q. Can you tell us about the blood test you are helping to develop to diagnose schizophrenia?
A. Our goal is to develop simple, rapid and inexpensive measurements that can probe a blood sample for chemical information of oxidative stress. We believe such measurements will assist researchers in understanding schizophrenia and help clinicians in managing this disease. Our approach is very non-traditional. Traditionally, a blood test would emerge from fundamental research of a disease that would resolve the disease’s mechanisms and identify the critical chemical components of these mechanisms. If/when such chemical “markers” became known, then a test could be developed. The most successful example of this approach is the glucometer that measures blood glucose and provides vital information to a clinician or patient. Our approach is different. We concede that no single chemical or set of chemical markers is known to provide vital information for clinicians to detect oxidative stress. Thus, rather than using the tools from chemistry, we are applying the tools from information processing. Specifically, we are developing methods to interactively probe a sample for chemical information in a manner that is somewhat analogous to sonar. We then analyze this chemical information to discern correlations between our measurements and the clinician’s expert opinions from diagnosis and symptom severity ratings.
Our approach is not aimed at replacing the blood test that provides detailed analysis of individual chemical components. Rather our approach aims to provide rapid access to chemical information at a global, systems level much like measurements of temperature, blood pressure and EKGs provide rapid access to global information of considerable clinical value.
Q. How soon can we can expect to see tests such as this in the clinic? Are there any hurdles that need to be overcome first?
A. Our goal over the next few years is to improve the measurement of oxidative stress and strengthen the correlations to disease metrics using schizophrenia as our model. Once this phase is complete, it should be relatively easy to build an instrument that will provide researchers with a simple tool that reports useful chemical information rapidly, cheaply and that is complementary to traditional analytical approaches. Moving the tool into the clinic will require overcoming the hurdles associated with FDA approval.
Q. What future research do you have planned?
A. Over the last couple years we’ve become convinced that signal processing offers exciting opportunities for extracting chemical information from complex samples. Since oxidative stress has been established as a major contributor to chronic and degenerative diseases, we will extend our approach to other diseases. I believe these types of measurements have tremendous potential to provide researchers and clinicians with new tools that are cheap, rapid and highly sensitive.
Dr. Payne was speaking to Anna MacDonald, Editor for Technology Networks
1 Kim, E., Winkler, T. E., Kitchen, C., Kang, M., Banis, G., Bentley, W. E., . . . Payne, G. F. (2017). Redox Probing for Chemical Information of Oxidative Stress. Analytical Chemistry, 89(3), 1583-1592. doi:10.1021/acs.analchem.6b03620