At the current time, there is no identified biomarker for Parkinson's disease (PD). In other words, there is no objective measure -- no lab or imaging test, for example -- that can tell whether a person has PD, what type of motor and non-motor symptoms will predominate and how those symptoms will change over time.
Having a biomarker for Parkinson's would both inform clinical care and accelerate research. A key potential biomarker is alpha-synuclein, the sticky protein that clumps in the brains of people with PD. These protein clumps -- called Lewy bodies -- are a hallmark of the disease thought to cause damage or death to dopamine-producing brain cells. Researchers can't currently visualize alpha-synuclein in the brains of people with PD while they're living. (This is, however, a priority area for the Foundation and MJFF is funding efforts to develop an agent to image alpha-synuclein in the brain.) They can, however, measure the protein in several areas outside of the brain, as alpha-synuclein is found throughout the body.
Researchers haven't yet determined the optimal location(s) or method(s) to sample alpha-synuclein. To meet this need, in 2016, MJFF launched the Systemic Synuclein Sampling Study (S4), an observational clinical study involving 60 people at varied stages of Parkinson's disease and 20 healthy volunteers. A new report, published in Biomarkers in Medicine, details the study's procedures and goals. The article describes the standardized collection and analysis protocols used to measure alpha-synuclein in each participant's spinal fluid, saliva and blood, as well as their skin, colon and salivary gland tissues.
S4 is the first study to evaluate alpha-synuclein in multiple body fluids and tissues within the same person and across a population of people at various points in PD. These results may lead to recommendations for optimal alpha-synuclein measurements in clinical trial participants as well as an understanding of how alpha-synuclein changes throughout the disease course.
As the study authors write, "The development of a peripheral alpha-synuclein biomarker would provide a valuable tool for confirming the diagnosis of PD, and possibly identification of the disease in its earliest stages, and provide a potential means of monitoring efficacy of potential disease modifying agents."
A tool that could facilitate diagnosis and gauge the impact of therapies in development would truly change the way we're able to conduct research and how quickly we can move therapies through the pipeline. That's why finding a biomarker and research such as this are so critical.