Study Rationale:
The need for biomarkers in Parkinson’s disease (PD) is crucial for the early diagnosis of PD; monitoring PD severity/progression; and developing treatments that can stop or slow PD progression. Our earlier study showed that the quantitative expression of a set of genes was altered in brains of PD patients compared to controls. Investigation of the most altered genes showed that their quantitative expression in blood was also dissimilar in PD patients compared to controls, which lead us to develop the PDx™ blood test. Remarkably, we found that the PDx test results are different in early stages of disease compared to advanced stages.
Hypothesis:
Our aim is to validate the association between the PDx test values and disease severity. We will further validate the ability of the PDx assay to diagnose PD patients.
Study Design:
We will test blood samples of PD patients (including those with scans without evidence of dopaminergic deficit or SWEDD patients) and control volunteers enrolled in the PPMI study. We will measure the PDx assay in blood samples taken at the beginning of the PPMI study as well as longitudinal follow-up samples. The association between PDx test values and clinical status at baseline and at follow-up time-points will be analyzed. We will compare the difference in PDx test values between the patient groups and between patient groups and controls.
Impact on Diagnosis/Treatment of Parkinson’s Disease:
Successful validation of the association of the PDx blood test results with disease severity and of its ability to diagnose PD will provide physicians with a new tool for the early diagnosis of the PD and monitoring PD progression. More accurate early diagnosis will enable early treatment with potential neuroprotective therapies.
Next Steps for Development:
Our next steps will be the completion of the assay’s commercial development (production and regulatory) for providing the PDx test to health care providers. Further development includes testing the PDx assay’s utility for monitoring drug response for personalized medicine and screening populations who are at risk for PD.