Project Lead(s): Parameswaran Nair
According to World Health Organization (WHO) estimates, 65 million people have moderate to severe chronic obstructive pulmonary disease (COPD) and more than three million people died of COPD in 2005.
About half of all asthma exacerbations and a third of COPD exacerbations are associated with an eosinophilic bronchitis. Yet, bronchitis is not measured in routine practice to guide therapy and, currently, treatment for bronchitis is based solely on symptoms and a measurement of airflow (FEV1).
Quantitative cell counts can reliably identify the number of eosinophils in sputum and treatment strategies guided by these counts can lead to significantly better outcomes. However, cell counts are not widely available and the results are not available in real time. Point-of-care assessments of eosinophil-specific activity may be provided by breathomics that profile the volume of compounds in breath.
The project aimed to develop a point-of-care test to detect and treat bronchitis by detecting markers of cellular activity in sputum, rather than enumerating cells quantitatively.
This involved developing a bioactive paper to detect eosinophil peroxidase as a marker of eosinophil activity and myeloperoxidase as a marker of neutrophil activity.
The specific objectives were to:
· Develop a read-out of the activity of eosinophils and neutrophils that could be a substitute for actually counting the cells in sputum
· Transfer these read-outs to a paper strip to develop the first prototype of a bio-active paper “dip-stick”-like test
· Collaborate with centres in India, where the approach could be tested after scaling up to produce a commercial and regulatory-approved, paper-based test strip.
The first challenge was to identify and develop a protein that would be specific for the eosinophil and one that would be specific for the neutrophil. Eosinophil peroxidase (EPX) was selected as the eosinophil protein and Myeloperoxidase (MPO) was selected as the neutrophil protein.
A technique to measure a protein is already commercially available for MPO. A robust assay for EPX was developed and validated, and it was demonstrated that this could be applied to raw sputum with minimal processing.
The project confirmed that the different components necessary to develop a prototype of a point-of-care test for eosinophilic bronchitis can be developed.
Both eosinophil activity (EPX) and neutrophil activity (MPO) can be detected accurately using an antibody-based lateral flow biosensor. The biosensor consists of four components: a sample application pad, a conjugate pad, a nitrocellulose membrane, and an absorbent pad.
The team plans to develop a commercial, affordable, point-of-care paper-strip.
Once this is complete, an application will be made for Phase II Transition To Scale funding to do a field trial in Canada and in India; then, to move the approach into clinical practice in both Canadian and Indian clinical practices, initially for the treatment of exacerbations of airway diseases (such as asthma, COPD and chronic cough).