Physicians may one day be able to diagnose Parkinson’s disease (PD) by analyzing tissue from a person’s salivary glands, says a new study supported by The Michael J. Fox Foundation (MJFF) from Charles Adler, MD, PhD, a neurologist at the Mayo Clinic Arizona.

In the past, says Adler, autopsies of Parkinson’s patients showed that abnormal proteins associated with Parkinson’s were found in particular glands under the lower jaw. His new study is the first to find similar proteins in living individuals with PD. 

Adler’s team took biopsies from 15 people with Parkinson’s who were not known to have salivary gland disorders. Tissue was removed from two different saliva glands — the submandibular gland, which is found under the lower jaw, and from the minor saliva glands in the lower lip. The abnormal Parkinson’s protein was found in nine of the eleven patients with enough tissue to study.

As of yet, there is no diagnostic test for predicting the onset of PD. Salivary glands have the potential to provide physicians with a relatively easy method for diagnosing Parkinson’s, and to do so early in the course of the disease, says Jamie Eberling, PhD, associate director of research programs at MJFF. 

“These findings are certainly promising,” she explains, “but more work is needed. Adler’s team will need to study additional patients on a much larger scale to confirm that proteins in the salivary glands could be a biomarker of PD.

“Should these results holds true, Adler’s work could have real implications for not only the early detection of Parkinson’s, but also, for potentially finding patients for clinical trials into drugs that could stop the disease before the motor symptoms occur.”