NEW YORK (360Dx) – As more researchers put emphasis on developing blood tests for conditions that are difficult to pinpoint, such as general pain, Ohio State University scientists have identified metabolic signatures for fibromyalgia that they believe could serve as a basis for developing a diagnostic test.
In a preliminary study, recently published in the Journal of Biological Chemistry, the researchers showed that it may be possible to deploy Raman and infrared spectroscopy to detect fibromyalgia in blood samples and differentiate the condition from other similar ailments, such as lupus and arthritis.
Luis Rodriguez-Saona, a researcher leading the Ohio State study, said in an interview that his team's discovery could be an important turning point in care of patients with a disease that is frequently misdiagnosed or undiagnosed.
Fibromyalgia is currently incurable, and treatment is limited to exercise, education, and antidepressants, but an accurate diagnosis has benefits that include ruling out other diseases, confirming for patients that their symptoms are real and not imagined, and guiding doctors toward disease recognition and appropriate treatment.
Rodriguez-Saona and his colleagues have been working for more than eight years to identify different fractions of the blood that might be associated with fibromyalgia and similar disorders.
Their technique involves separating serum from large molecules and passing it over a highly refractive substrate inside a spectrometer. The substrate enhances scattered photons being transmitted to a detector and enables the collection of metabolic spectra associated with fibromyalgia and similar disorders, such as rheumatoid arthritis and lupus.
Their preliminary study included 50 people with a fibromyalgia diagnosis, 29 with rheumatoid arthritis, 19 with osteoarthritis, and 23 with lupus.
The researchers used pattern recognition and analysis of the obtained spectra to identify specific bands that differentiate fibromyalgia in patient samples. They found unique spectral signatures that achieved 100 percent accuracy in clustering subjects into classes with fibromyalgia, rheumatoid arthritis, or systemic lupus erythematosus, Rodriguez-Saona said.
He and his colleagues believe that the preliminary results bring them a step closer to a commercial blood test that physicians may be able to deploy in hospitals or in primary care settings.
They have begun discussing requirements for clearance of the test with the US Food and Drug Administration and are looking into ways to make the testing method more efficient, Rodriguez-Saona said.
Within two to three years, the technology licensing office at Ohio State may be ready to decide on the best route to commercialize the technology, he added. At present the team is focused on further validating its findings and has not thought about a commercial strategy, such as launching a spinoff company to focus on commercialization, partnering with existing diagnostic companies, or licensing out developed technology and intellectual property.
Difficult diagnosis
To diagnose fibromyalgia, doctors now rely on physical exams and information that patients report about their symptoms. No blood test exists to help doctors make a clear and quick diagnosis, and patients can therefore be left without receiving proper care or advice on managing chronic pain and fatigue.
Many undiagnosed patients are prescribed addictive opioids that have not been shown to benefit people with the disease. In chronic pain clinics, the Ohio State researchers said, about 40 percent of patients on opioids meet the diagnostic criteria for fibromyalgia, and the condition often gets worse while the patients are taking opioids.
Confusing the diagnosis, a group of very similar functional disorders have their origin in the brain but are expressed differently in the body, and for suitable treatment physicians need to be able to pinpoint the specific disorder, Rodriguez-Saona noted.
More researchers are looking into using diagnostic testing to positively impact the opioid epidemic. For example, researchers at Indiana University School of Medicine, the Indianapolis VA Medical Center, and the Scripps Research Institute are developing gene expression-based biomarkers for a blood-based diagnostic test to measure and quantify pain.
Alexander Niculescu, one of the lead developers of the gene expression test at Indiana University, said in an interview that the Ohio State researchers now need to replicate what they have found in independent cohorts outside of those they used for discovery.
This is necessary "to make sure that they have true findings," he said, adding that "it is encouraging that [the Ohio State researchers] report a correlation with symptom severity."
Daniel Clauw, a professor of psychiatry and pain researcher at the University of Michigan Health System, not involved in the Ohio State research, said, "If these results are replicated in a different group of fibromyalgia patients and controls, then this would be a very exciting development in the field."
However, until that happens it is premature to say that the work will lead to biomarkers with the potential to be targeted by diagnostic tests, he said.
Tadafumi Kato, a professor and team leader in the Riken Brain Science Institute in Saitama, Japan, who also was not involved in the Ohio State research, said that the study "seems to satisfy the criteria" for replication in an independent sample set. However, the study does not identify specific molecules that can discriminate fibromyalgia from other diseases, and in this sense it should be regarded as preliminary research, he said.
Rodriguez-Saona noted that his group has applied for funding from the National Institutes of Health to examine 150 to 200 subjects per disease group, including patients with fibromyalgia, rheumatoid arthritis, osteoarthritis, and lupus, to see if their preliminary findings can be replicated in a larger, more-diverse population.
The group has been using a benchtop system, but it is looking into developing a smaller, portable system to make testing available to "different points of service, including doctors' offices," he said.