PPMI Study Expanding Enrollment

The Parkinson’s Progression Markers Initiative (PPMI), a study sponsored by The Michael J. Fox Foundation, is expanding to recruit more participants, the Foundation announced.

Currently, the study (NCT04477785) is recruiting new participants — both with and without Parkinson’s disease — at Banner Research Institute in Sun City, Arizona, Baylor College of Medicine in Houston, Texas, the Institute for Neurodegenerative Disorders in New Haven, Connecticut, and Northwestern University in Chicago, Illinois. A full list of trial locations and contacts for each location is available here.

In the coming months, the PPMI also plans to recruit people with risk factors for Parkinson’s, including individuals with a first-degree family member with Parkinson’s, those with certain Parkinson’s-associated mutations, and people with certain clinical risk factors (e.g., loss of smell or physically acting out dreams).

Individuals interested in participating in the study can fill out a short eligibility survey here.

The PPMI is an observational study — a type of clinical trial where no experimental treatment is given. Instead, participants are assessed over time to collect clinical and biological data. The study, first launched in 2010, has already enrolled more than 1,400 participants, who are completing clinical exams, undergoing brain scans, and contributing biological samples.

The data collected through the study is being used by researchers to better understand how Parkinson’s disease manifests and progresses. According to the Foundation, PPMI data downloads have crossed the 6 million mark.

Even as data continues to be collected, multiple research efforts using PPMI data are ongoing. Two recently-published studies using PPMI data highlight the type of research this data facilitates.

In one study, researchers determined that measuring levels of the protein neurofilament light chain (NfL) in the blood could be used to assess Parkinson’s progression. The study, “Validation of Serum Neurofilament Light Chain as a Biomarker of Parkinson’s Disease Progression,” was published in Movement Disorders.

NfL is released into the blood when neurons are damaged; as such, the protein is commonly used as a marker of neurological damage.

In the study, researchers analyzed NfL levels in blood samples from 1,190 PPMI participants, determining that levels were significantly higher in people with Parkinson’s than in those without. NfL levels also were associated with the severity of symptoms — both motor and non-motor — indicating that a blood test measuring NfL levels may be useful as a way to measure disease progression in people with Parkinson’s.

In the second study, researchers investigated the association between depression and mild cognitive impairment (memory and thinking problems beyond what is expected with normal aging) in people with Parkinson’s. The study, “Depressive symptoms are associated with worse cognitive prognosis in patients with newly diagnosed idiopathic Parkinson disease,” was published in Psychogeriatrics.

By analyzing data from 263 PPMI participants with early Parkinson’s disease collected over a four-year period, the researchers determined that people with more depressive symptoms at the start of the study were significantly more likely to develop mild cognitive impairment later on. The results also indicated a link between depression and more brain atrophy (shrinkage) later.

More information about the PPMI is available here.