Researchers in England have developed a non-invasive technique for diagnosing asthma that detects metabolic biomarkers in a saliva sample. The technique diagnosed asthma with greater than 80% accuracy, according to results of a study published in Analytical Methods.
“Unlike other sampling methods, such as expired breath analysis, saliva can be collected by passive drool from the very young to the very old without causing distress,” explained co-lead researcher Colin Creaser, PhD, Professor of Analytical Chemistry at Loughborough University, in Loughborough, UK.
Dr. Creaser and colleagues wondered if techniques for the metabolic profiling of saliva—such as a novel test that identifies physiological stress from exercise—could also be applied to diagnose asthma.
“We were very excited to discover that they could,” he said.
For this study, Dr. Creaser and co-lead investigator Dominick Shaw, MBChB, MD, from the Respiratory Research Unit at Nottingham City Hospital in Nottingham, UK, collected passive drool samples from 9 patients with asthma and 21 healthy individuals.
To identify metabolic biomarkers for asthma, the researchers then analyzed the samples using ultra-high performance liquid chromatography combined with high-resolution mass spectrometry (UHPLC-MS)—an analysis that took only 15 minutes. From a total of 35,011 molecular features, the analysis identified 10 that distinguished the asthma patients from the healthy subjects.
“To our knowledge, this is the first study to employ a passive drool saliva test combined with UHPLC-MS as a potential discriminatory tool for asthma,” the authors concluded.
The investigators now plan to validate the metabolic biomarkers using longitudinal studies. If validated, the saliva test could be used not only for simple and early asthma diagnosis, but also for ongoing patient monitoring, the researchers noted.