ST. PAUL, Minn., April 11 (UPI) -- Israeli researchers said Friday they have developed a simple, "revolutionary" blood test that for the first time would allow doctors to detect the onset of Parkinson's disease in its very earliest stages.
The authors say the new test can give providers an early warning of when a patient has contracted Parkinson's well before the appearance of noticeable motor symptoms, such as its characteristic tremors, at which point significant damage to neurons in the brain already has been done.
It could be of immense benefit to people who may be genetically predisposed to Parkinson's, a progressive neurodegenerative disorder caused primarily by the death or damage to neurons in the brain that produce dopamine.
Such a test could also play a key role in future clinical trials in for new drugs seeking to slow or prevent the disease, advocates say.
The research, led by the laboratory of renowned neurologist Hermona Soreq at the Hebrew University of Jerusalem, has produced what her team says is a non-invasive blood test that works by measuring levels of genetic material fragments present in the bloodstream that are linked to the neurological damage caused by Parkinson's disease.
The results of a study of its effectiveness and accuracy conducted by Hebrew University doctoral student Nimrod Madrer were published Friday in the scientific journal Nature Aging.
They showed that by assessing the bloodstream levels of two molecular biomarkers, which have "traditionally been overlooked" in Parkinson's research, the new test can "distinguish pre-symptomatic Parkinson's patients from healthy controls with an accuracy surpassing that of existing clinical diagnostic tools."
The genetic materials being measured include two types of "transfer RNA fragments," or tRFs. The test compares the ratio of Parkinson's-specific tRFs to others associated with mitochondria, the "powerhouse" portion of cells which produce energy.
An increase in the Parkison's tRFs, along with a corresponding decrease in mitochondrial tRFs, signal the earliest stages of Parkinson's disease with a diagnostic accuracy of 0.86 -- better than anything now possible, the study claims.
Soreq is the Charlotte Schlesinger Professor of Molecular Neuroscience at the Silberman Institute for Life Sciences and a founding member of the Hebrew University's Edmond and Lily Safra Center for Brain Sciences.
She told UPI the development of a simple blood test for early detection of Parkinson's disease "can offer new opportunities for seeking disease-changing therapeutics, which is impossible today as the disease is only detected when most of the relevant neurons have already died."
Such a test could help address omnipresent fears among those with family histories of the disease. According to Johns Hopkins University, about 15% of people with Parkinson's disease have a family history of the condition.
Family-linked cases can result from genetic mutations in a group of genes, including LRRK2, PARK2, PARK7, PINK1 and SNCA, although the interactions between the mutations and an individual's risk of developing Parkinson's largely remains a mystery.
Still, genetically predisposed people would be among the prime beneficiaries of a successful early-detection test, Soreq said.
"There are people who carry Parkinson's disease-causing mutations, they should surely take the test as only a fraction of such carriers develop Parkinson's disease, but all of them are scared because they carry these mutations," she said.
"Others may take it due to exposure to risk-elevating materials -- pesticides, for example -- and should also be cautious."
The development of a simple blood test that detects Parkinson's disease before it can be diagnosed in the clinic would be "an incredibly exciting advancement for the PD community," American Parkinson Disease Association Chief Mission Officer Dr. Rebecca Gilbert told UPI.
Currently, Parkinson's disease is diagnosed based on motor symptoms, such as slowness, stiffness, tremor and balance problems, which develop years or even decades after the first abnormalities are present in the brain.
"There are certain 'pre-motor symptoms,' such as smell loss, constipation and REM behavior sleep disorder, which frequently pre-date motor symptoms and are seen in people who are at risk of developing full-blown motor PD," Gilbert said. "One major question about this blood test is: How early in the disease process is it abnormal?"
The ability to detect pre-motor Parkinson's "would be incredibly valuable, as early detection can empower people to adopt healthy lifestyle changes that may slow the onset or acceleration of symptoms," she added.
The test also could be key in future clinical trials for drugs to prevent the diseases by using it to test compounds in people who have pre-motor Parkinson's disease, ensuring that the trial cohort are all uniformly affected and thus making the results of the trial more reliable.
"And, once neuroprotective treatments are available, it will be even more crucial in identifying Parkinson's in its earliest stages, to allow people access to a disease-slowing medication that could be game-changing," Gilbert said.
