Sarah Hamm-Alvarez, PhD: Developing a Biomarker for Parkinson Disease

Identifying, studying, and verifying a potential biomarker can be a lengthy affair. However, success often means clinicians have a new tool to better diagnose a condition like Parkinson disease and to diagnose the condition earlier in the disease progression.

A biomarker for Parkinson disease might mean that patients can begin receiving treatment before irreversible neurological damage occurs.

Sarah Hamm-Alvarez, PhD, Professor of Ophthalmology at the USC Roski Eye Institute at the Keck School of Medicine of USC, spoke with MD Magazine® about this biomarker research, which she presented at the 2019 Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) in Vancouver, BC.

Hamm-Alvarez highlighted the collaborative nature of the project that has included colleagues from the neurology, pharmacy, and preventive medicine departments.

“Part of the passion for the project is driven by the clinical need that I sense from my neurology colleagues and their frustration that they don't have better ways to diagnose patients at early disease states,” said Hamm-Alvarez.

In part 1 of the interview, Hamm-Alvarez introduced the study and the team’s reasons for investigating tears for a Parkinson biomarker. In part 2, she described the study methods and the differences they found in basal and reflex tears.

What's the process for developing a biomarker?

How have various departments collaborated in this project?

First you start by establishing a correlation, which we have done. And right now what we're doing is that we are actually recruiting patients with Parkinson’s disease that are at different times from disease diagnosis and this, we think, will reflect disease severity. So, what we're trying to do is to see if the levels of oligomeric α-synuclein are correlated with time from disease diagnosis. So, we're going to try to get a sense of the disease severity. We also are eventually planning to try to test this in patients without a diagnosis, as well as patients who exhibit symptoms that overlap with Parkinson's disease, such as patients with atypical parkinsonian syndromes and patients with other neurological disorders, of course, to determine how specific this may be, and also whether this has predictive ability going forward if a patient is at an early stage of Parkinson's disease.This project is very much a team effort we have a whole team at the University of Southern California including colleagues in neurology and pharmacy and preventive medicine. We work very closely with Mark Liu in neurology, who is a neurologist, and who is very excited about the potential for applying this in his clinic. So, I think that part of the passion for the project is driven by the clinical need that I sense from my neurology colleagues and their frustration that they don't have better ways to diagnose patients at early disease states.