Objective/Rationale:
When a Parkinson’s disease patient first experiences motor symptoms, most of the neurons in the part of the brain affected by the disease have already died and therefore the disease is irreversible. Early detection could improve disease management by allowing for early intervention. We have identified biomarkers useful for distinguishing medicated patients from control volunteers. In the current study, we will determine whether the biomarkers are useful for distinguishing non-medicated patients from controls.
Project Description:
The genetic material, or DNA, in blood cells is the same for most Parkinson’s patients as that found in control individuals. DNA encodes RNA, the information needed to produce the components that comprise our cells. The amount of RNA produced from each gene in our DNA is regulated by both genetic and environmental factors. In Parkinson’s patients the expression of some genes has become dysregulated, leading to a change in the abundance of some RNAs compared to healthy individuals. By quantifying these RNAs, we can use them as markers to identify patients. We will quantify RNAs in blood collected from participants in the Parkinson’s Progression Markers Initiative clinical trial.
Relevance to Diagnosis/Treatment of Parkinson’s Disease:
These studies are expected to identify markers in blood that will be useful for distinguishing early stage non-medicated Parkinson’s patients from healthy individuals. They will form the foundation of future studies designed to identify patients before the onset of motor symptoms. This will allow physicians to provide therapeutic treatment much earlier to patients, ideally before irreversible damage has occurred.
Anticipated Outcome:
It is expected that these studies will identify blood markers useful for identifying early stage Parkinson’s patients. Non-invasive readily obtainable markers such as these will be useful to physicians for early diagnosis so that they might provide appropriate therapeutic treatments as early as possible. Several labs are currently researching therapies that are expected to slow disease progression. With the markers identified in these studies, the neuroprotective therapies may be initiated early after disease onset in the future.
Final Outcome
Identification of accurate, sensitive and non-invasive biomarkers for early-stage Parkinson's disease will be beneficial for diagnosis so that treatment may be initiated as early as possible. Previously we identified several putative biomarkers for Parkinson's disease in clinical studies in which the patients were already receiving medications. In this new study, we tested nine potential blood biomarkers in people with Parkinson's who were recently diagnosed and not yet receiving medications. Two markers were identified that were useful for distinguishing drug naïve PD patients from healthy individuals. In addition, some of the markers correlated with disease severity measures in PD including motor symptoms and cognitive decline. The results from this study indicate that these markers may be useful for the early diagnosis and classification of PD patients, which is expected to improve treatment.
March 2015