New Rapid Test Accurately Identifies Eosinophils in Sputum to Guide Asthma Treatment

By LabMedica International staff writers
Posted on 03 Aug 2023

Image: The new rapid test can identify white blood cells in complex biological samples (Photo courtesy of Freepik)

Following years of extensive research into the fundamental causes of asthma and other respiratory diseases, a group of scientists has developed a simple, rapid diagnostic test capable of identifying a key driver of severe asthma.

Researchers at McMaster University (Hamilton, ON, Canada) and St. Joseph’s Healthcare Hamilton (Ontario, Canada) have spearheaded the development of a novel rapid test that quickly and accurately detects eosinophils, a type of white blood cell, by identifying their protein signatures, even in complex biological specimens such as sputum. Quick access to this reliable information about eosinophils can aid doctors in making critical patient care decisions. The test resembles the familiar COVID-19 home test, enabling easy adaptation for its large-scale production once approved for clinical application.

The researchers created this test by developing a protein-targeting component called a DNAzyme and modifying it for use in the rapid test. DNAzymes, first isolated in 1994, have primarily been used for detecting metals or bacterial targets. No one had previously succeeded in leveraging DNAzymes to target specific protein markers. Having surmounted this challenge, the researchers now believe that this test platform could be tailored to identify any biologically-derived material through its protein signature.

The team is now planning a comprehensive clinical trial for this novel test, marking the next crucial step towards its market launch. A rapid diagnostic test for detecting elevated eosinophil levels could assist clinicians in making informed decisions about the administration of medications such as steroids or new biologics to patients suffering from severe asthma and other lung conditions linked to eosinophilia, including severe cough and chronic obstructive pulmonary disease (COPD). Additionally, the test could help curb the unnecessary usage of antibiotics.

“This test and others like it can have the kind of lasting, meaningful impact that will improve or even save many lives,” said John Brennan, director of McMaster’s Biointerfaces Institute.