Putting saliva to good use

Dr. Mervyn Gornitsky
Professor Emeritus
McGill University

If researchers could find a non-invasive, physiological tool to diagnose Parkinson’s disease, it might be easier to start treatment earlier. At McGill University, Dr. Mervyn Gornitsky believes he has done just that—by measuring the quantity of a protein called heme oxygenase-1 (HO-1) in samples of the saliva of people who have Parkinson’s. Gornitsky, an oral surgeon, is using his biobank of 4,000 saliva samples to confirm the test’s ability to determine the presence of Parkinson’s in people who are in the early stages of the disease, even before they show tremors, stiffness or other motor control symptoms.

As an oral surgeon in Montreal, Dr. Mervyn Gornitsky was constantly surrounded by his patients’ spit.

“Here I was with all of this liquid around me, watching it go down the drain and wondering whether I could use saliva and find out if there’s anything in saliva that could determine disease,” says Gornitsky, a professor emeritus at McGill University. 

Today, he is doing just that and has created a biobank of more than 4,000 saliva samples that he’s using to help diagnose Parkinson’s disease, as well as other illnesses. This research project was made possible through a Pilot Project Grant for $49,200 over one year from the Parkinson Canada National Research Program.

“We found all kinds of things in saliva because it absolutely has many different types of chemicals and materials that are part of your saliva and salivary glands,” he says.

Gornitsky measures the amount of a protein called heme oxygenase-1 (HO-1) in saliva, correlating the quantity of the protein to people in the early stages of Parkinson’s disease.  

In an early study, he and his colleagues have already demonstrated that the highest levels of HO-1 are found in the saliva of people in the early stages of Parkinson’s disease.

“We were the first to use saliva as a biomarker for early Parkinson’s, and that (discovery) was published just recently in Movement Disorders, the official journal of the Movement Disorders Society,” Gornitsky says.

Now, he’s refining the test to diagnose Parkinson’s even earlier, in people who don’t yet exhibit any of the motor symptoms such as stiffness, tremors or rigidity that plague people in later stages of the illness.  

Researchers have already determined that people who’ve lost their sense of smell and/or have digestion problems or other seemingly unrelated symptoms may go on to develop Parkinson’s. This is the population of people Gornitsky is targeting in his research, as well as those with a family history of the disease.

If those people could be diagnosed early, they could begin taking levodopa right away, or benefit from any new drugs developed to halt Parkinson’s progression.

“If we get people diagnosed early before they have the movement disorder symptoms that normally come with Parkinson’s, then we could delay those movement symptoms to a later date,” Gornitsky says. “It’s not going to cure the disease but we will maybe be able to get a few years where people will not have the severe Parkinson’s effects.”

Eventually, Gornitsky hopes saliva could be the basis for an easy, inexpensive test that doctors could use to diagnose Parkinson’s right in their offices.