Study Rationale:
Recently, researchers discovered a specific set of molecules in the oily substance produced by the skin of people with Parkinson’s disease (PD). The findings stemmed from work with a woman with a uniquely sensitive sense of smell; this individual could identify people with PD based on a characteristic, musky scent she could reliably detect by sniffing their T-shirts. The observation raises the question of whether a “biochemical fingerprint” may be present in the skin secretions of people with PD during the so-called prodromal phase of the disease, years before they develop the typical motor symptoms that lead to their diagnosis.
Hypothesis:
This study aims to investigate whether the same set of biochemical molecules are present in the oily skin secretions of individuals who will ultimately develop PD, and whether this olfactory fingerprint differs from that of healthy controls and people currently diagnosed with PD.
Study Design:
We will invite 480 men and women to collect skin secretions by rubbing their upper back with gauze. These individuals are participants in a set of ongoing cohort studies at Harvard: the Nurses’ Health Study and Health Professionals Follow-up Study. In these large studies, about 20,000 individuals were screened for signs that commonly occur in combination during the prodromal phase of PD, such as constipation, a decreased sense of smell and a tendency to physically act out dreams during sleep. We will compare the compounds in samples provided by these individuals to those in individuals with PD and healthy volunteers.
Impact on Diagnosis of Parkinson’s Disease:
If, in this study, we determine that the biochemical fingerprint of PD patients is already present in individuals who have not yet been diagnosed but who will develop PD, we could improve how early — and how easily — we can diagnose and ultimately treat PD.
Next Steps for Development:
The next step would be to investigate whether this biochemical fingerprint and characteristic skin odor can be used to predict whether and when an individual will develop PD.