When Joy Milne strolls down a crowded street, she can tell if the passer-by she just bumped into is suffering from Parkinson’s disease. Milne is a retired Scottish nurse who, thanks to an unusual sense of smell, can smell the typical smell of this neurodegenerative disease long before symptoms arise. She has made this ability available to science: together with her a team of researchers from the University of Manchester has created a non-invasive test that recognizes the disease in just three minutes, and which hopefully will soon be used in the clinical setting.
Alarm bell. Milne’s “superpowers” were the protagonists of a difficult personal story. When the woman’s husband was 33 years old, Milne noticed that her skin had started to give off a new and pungent, almost musky smell, especially in the area around her shoulders and behind her neck. Twelve years later the man was diagnosed with Parkinson’s disease. The woman reconnected the two things only when she, attending a support group for patients and families, she noticed that same smell in the other patients (of Milne’s abilities and of the first developments of the affair. we had written here).
The signature of the disease. In the following years Joy had started collaborating with some biotechnologists and chemists from the University of Edinburgh and Manchester, who in 2019 had finally managed to identify the molecules responsible for that odor, some of which are present only in people with Parkinson’s. Now that team, under Milne’s supervision, has developed a simple test – a swab to be passed on the skin – that would appear to distinguish cases of Parkinson’s in people awaiting diagnosis with 95% effectiveness.
The answer goes through the analysis of the sebum, the oily substance naturally produced by the skin that is thought to undergo chemical alterations in those affected by this disease. It is collected from the back of the patient’s neck and back, an area that is usually washed less often, and then analyzed with a technique called mass spectrometry, which “names” the specific molecules within the patient. sample. Comparing the sebum of 79 people with Parkinson’s with that of 71 healthy people, it was found that in the former there were 500 unique molecules, characteristic of the disease.
Precious time. Scientists are now in the delicate phase of test validation and knowledge transfer in the clinical setting. The hope is to arrive at a diagnostic tool that can be used primarily in Manchester hospitals and GPs – for further confirmation of effectiveness – within a couple of years. Currently there is no single specific test to recognize Parkinson’s disease: doctors make the diagnosis mainly by observing the symptoms, often months or years after their onset.
At present there is no cure for this disease, but there are tools, pharmacological and not only, to alleviate the symptoms and restore a better quality of life to patients and families. Movement and some dietary changes can, for example, be helpful, and getting psychological support would be equally essential.
Make the difference. Milne and the researchers hope their test will help. The woman’s husband died in 2015, after a life spent – first as a doctor and then as a patient – investigating the relationship between Parkinson’s and its olfactory markers. Now Milne is collaborating with other groups of scientists to understand if other diseases (such as tuberculosis or certain types of tumors) also have a characteristic odor signature, which only some with super-gifted receptors are able to perceive.