Finally, the integrity of clinical trials is undermined by the lack of an accurate screen, Dr. Beal notes. "Every time you do a clinical trial into Parkinson's and you have patients that are misdiagnosed, it enters 'noise' into the analysis, skewing the results. A truly reliable test could help eliminate that," the researcher notes.
That's why encouraging results for the new test -- based on a patient's "metabolomic profile" -- are so important.
Metabolomics is the study of changes in thousands of distinct, very small molecules found in body fluids or tissues. "Anytime you have a genetic or environmental perturbation, these molecules are altered in specific ways," Dr. Beal explains.
Because Parkinson's treatment could itself trigger some of these alterations, the researchers first compared metabolomic patterns in the blood of Parkinson's patients who were not undergoing treatment versus those who were medicated. "That gave us a 'medication-free' profile that we could use going forward," Dr. Beal explains.
In the next stage of the research, the team compared blood samples from 66 patients with Parkinson's disease against 25 healthy controls (most of whom were the patients' spouses). The metabolomic analysis included over 2,000 small molecules found in the blood.
"We discovered a clear differentiation between the metabolomic profiles of the Parkinson's disease patients versus those of the controls," Dr. Beal says. "No one molecule was definitive, but a pattern of about 160 compounds emerged that was highly specific to Parkinson's patients."
The significance of many individual compounds to the disease remains unknown and will be the focus of future study. But changes in a few well-known metabolites linked to oxidative stress were clearly linked to Parkinson's. These included low levels of the antioxidant uric acid; an increase in blood levels of anot
|Contact: Kathleen Robinson|
New York- Presbyterian Hospital/Weill Cornell Medical Center/Weill Cornell Medical College