An assay using mass spectrometry could go to clinical trial within two years
Dark Daily has regularly observed that humans generate a variety of volatile substances—particularly in breath—which can be used for diagnostic purposes. But what if people, like certain trained animals, could smell the presence of disease before the onset of symptoms? What types of clinical laboratory testing biomarkers could be developed based on human-generated volatile organic compounds?
In “Woman Who Can Smell Parkinson’s Disease in Patients Even Before Symptoms Appear May Help Researchers Develop New Clinical Laboratory Test,” Dark Daily covered the unique story of Joy Milne, a retired nurse from Perth, Scotland, who claimed she could “smell” her husband’s Parkinson’s disease a decade before he was diagnosed with the illness.
As strange as that may sound, Milne’s olfactory abilities were confirmed by researchers at the Center for Regenerative Medicine at the University of Edinburgh and have now led to a clinical laboratory diagnostic Parkinson’s test based on body odor.
Researchers at the University of Manchester (UM) in the United Kingdom (UK) say their “breakthrough” test to diagnose Parkinson’s disease “can diagnose disease from skin swabs in three minutes,” according to a university press release.
The researchers published their findings in JACS AU, a Journal of the American Chemical Society, titled, “Paper Spray Ionization Ion Mobility Mass Spectrometry of Sebum Classifies Biomarker Classes for the Diagnosis of Parkinson’s Disease.”
Perdita Barran, PhD (right), head of the University of Manchester research team that developed the mass spectrometry Parkinson’s test, is shown above with Joy Milne (left), the retired nurse from Scotland who inspired Barran’s team to develop a new Parkinson’s biomarker and method for identifying it. “We are tremendously excited by these results which take us closer to making a diagnostic test for Parkinson’s Disease that could be used in clinic,” she said in a press release. A viable clinical laboratory test for Parkinson’s disease is greatly needed, as more than 10 million people worldwide currently live with the neurodegenerative disorder. (Photo copyright: University of Manchester.)
Using Mass Spectrometry to Analyze Sebum
Increased sebum, which is produced by the sebaceous glands, is a hallmark of Parkinson’s, the researchers noted.
Their new method involves analysis of sebum using mass spectrometry, according to the JACS AU paper. The method, the researchers claim, makes it possible to diagnose Parkinson’s disease from skin swabs in three minutes.
“There are no cures for Parkinson’s, but a confirmatory diagnosis would allow [Parkinson’s patients] to get the right treatment and get the drugs that will help to alleviate their symptoms,” Perdita Barran, PhD, told the Hull Daily Mail. Barran is Chair of Mass Spectrometry in the Department of Chemistry and Director of the Michael Barber Centre for Collaborative Mass Spectrometry at UM’s Manchester Institute of Biotechnology. “What we are now doing is seeing if (hospital laboratories) can do what we’ve done in a research lab in a hospital lab,” she added.
Sebum Analyzed with Mass Spectrometry
Parkinson’s disease—the world’s fastest growing neurodegenerative disorder—needs “robust biomarkers” that could advance detection and head off onset of motor symptoms such as tremor, rigidity, and postural instability, the researchers note in their paper.
Their recent study builds on earlier 2019 findings they published in ACS Central Science about volatile compounds in sebum possibly being used as Parkinson’s biomarkers.
“Sebum is an underexplored biofluid, which is readily obtained from non-invasive skin swabs, which primarily consists of a mixture of triglycerides, cholesterol, free fatty acids, waxy esters, and squalene,” the researchers explained in their JACS AU paper.
The scientists sought, “to develop a method to analyze sebum in its native state to facilitate rapid assessment of the Parkinson’s disease status. Paper spray ionization mass spectrometry, which allows the direct analysis of compounds from paper, has previously been demonstrated to detect small molecules from unprocessed biofluids, such as blood and urine, but not to date with sebum,” they wrote.
The UM researchers used mass spectrometry to analyze sebum collected on cotton swabs from the backs of 79 people with Parkinson’s and 71 healthy individuals, BBC Scotland News reported.
Depanjan Sarkar, PhD, Research Associate, University of Manchester, further explained the technique in the UM news release:
- Sebum is taken from the swab to filter paper cut in a triangle.
- Using a solvent and voltage, sebum compounds transfer into the mass spectrometer.
“When we did this, we found more than 4,000 unique compounds of which 500 are different between people with Parkinson’s compared to the control participants,” Sarkar said.
Fatty Acids Make Assay Possible
Could fatty acids pave the way to an assay? The UM researchers believe so.
“We have identified two classes of lipids, namely [triglycerides] and diglycerides, as components of human sebum that are significantly differentially expressed in PD,” the researchers wrote in JACS AU. “Non-invasive sampling followed by PS-IM-MS [paper spray-ion mobility–mass spectrometry] analysis targeting these compounds could provide an inexpensive assay to support clinical phenotyping for the confirmatory diagnosis of Parkinson’s disease.”
A clinical trial for their test, which costs about $20, may be done within two years in Manchester area, the Daily Mail reported.
When Dark Daily reported in 2020 on Joy Milne’s unique ability to smell her husband’s Parkinson’s disease before it was formally diagnosed, we predicted a diagnostic test for Parkinson’s may be years away. And here it is, albeit with regulatory clearance needed following clinical trials.
It may in fact be possible to leverage sebum analysis to detect other diseases, the UM researchers noted.
For diagnostics developers, this story of Joy Milne and her husband Les Milne is a useful example of how, in tracking the life of a specific patient with a specific disease and close family members, researchers were able to identify a new class of biomarkers that could be used in a diagnostic assay.
It will be interesting to follow the University of Manchester researchers in their quest for a diagnostic mass spectrometry clinical laboratory test for Parkinson’s disease. According to Parkinson’s Foundation statistics, about 10 million people worldwide live with the neurodegenerative disorder. Such a new diagnostic test could be vitally important to medical laboratory care, and to patients and their families.
-Donna Marie Pocius