A study led by the School of Health and Medicine at the University of Lancaster in the UK suggests it may be possible to detect Parkinson’s disease in the early stages, long before external symptoms emerge, with a simple blood test that looks for a marker called phosphorylated alpha-synuclein. A report on the study appears in the December issue of the FASEB Journal.

Lead investigator Dr David Allsop, told the press:

“A blood test for Parkinson’s disease would mean you could find out if a person was in danger of getting the disease, before the symptoms started.”

Allsop and colleagues first showed phosphorylated alpha-synuclein is common in people with Parkinson’s disease, and then developed a way to detect it in a blood sample.

Allsop said a diagnostic tool that helps detect Parkinson’s disease at a very early stage “would help the development of medicines that could protect the brain, which would be better for the quality of life and future health of older people.”

For their study, the researchers examined blood samples from a group of 32 people diagnosed with Parkinson’s disease and a group of 30 healthy people of the same age who did not have the disease (the controls). They took four samples from the participants with Parkinson’s disease, one every month for four months.

When they analyzed the samples they found:

“The levels of [alpha-synuclein] in plasma varied greatly between individuals, but were remarkably consistent over time within the same individual with PD [Parkinson’s disease].”

They measured levels of three different forms of alpha-synuclein, including phosphorylated alpha-synuclein.

Their analysis showed that participants with Parkinson’s disease had sigificantly higher levels of phosphorylated alpha-synuclein compared to the controls. This was not the case for the other forms (oligo-alpha-synuclein, and oligo-phospho-alpha-synuclein), nor for the total of all three.

Based on these findings, Allsop and colleagues then went on to develop a simple test that detects phosphorylated alpha-synuclein in the blood that would allow Parkinson’s disease to be diagnosed at the stage where brain damage has started to occur, which is long before external symptoms emerge.

They write:

“Immunoblots of plasma revealed bands (at 21, 24, and 50-60 kDa) corresponding to phosphorylated [alpha-synuclein]. Thus, phosphorylated [alpha-synuclein] can be detected in blood plasma and shows more promise as a diagnostic marker than the nonphosphorylated protein.”

Dr Gerald Weissmann is Editor-in-Chief of the FASEB Journal. He said most people think of Parkinson’s as the outward symptoms, the involuntary movements, but “many people with Parkinson’s also develop neurological problems that may be more difficult to detect right away”.

“Having a blood test not only helps doctors rule out other possible causes of the outward symptoms, but it also allows for early detection which can help patients and their caregivers prepare for the possibility of the mental, emotional, and behavioral problems that the disease can cause,” he added.

The researchers also noted that:

“Longitudinal studies undertaken over a more extended time period will be required to determine whether [alpha-synuclein] can act as a marker of disease progression.”

Written by Catharine Paddock PhD