Australian respiratory researchers have once again challenged the ongoing usefulness of asthma-COPD overlap syndrome (ACOS) as a disease entity.
In an editorial in the European Respiratory Journal, Professors Vanessa McDonald and Peter Gibson from the Hunter Medical Research Institute suggested it was time to ditch the label.
“In addition to ACOS we are now starting to see reference to BCOS (bronchiectasis–COPD overlap syndrome), CCOS (cardiac–COPD overlap syndrome), and so on, so do we continue through the alphabet of syndromes?”
“Or should we abandon ACOS, as has been previously proposed and opt for treating the patient and their problems irrespective of their disease label: that is, use a personalised medicine approach?”
Speaking to the limbic, Professor Gibson said the term ACOS had outlived its usefulness.
“ACOS had some value in the beginning as it broke the rigid thinking about asthma and COPD as completely separate diseases. It raised awareness that patients are quite variable but the label is not a solution to the problem,” he said.
Their editorial was in response to a study, which applied six different definitions for ACOS to participants with asthma/COPD enrolled in the Netherlands Epidemiology of Obesity study.
The study found the prevalence of ACOS in the asthma/COPD population ranged between 4.4% and 38.3% depending on the definition used.
“Given the low agreement between definitions, differences in prevalence, patient characteristics and risk of exacerbations, consensus about the definition of ACOS in different care settings is urgently needed,” the study concluded.
“What it shows is a problem with definitions. ACOS is not useful as a disease concept as it is highly dependent on the definition used,” Professor Gibson said.
He added that the best predictors of response to treatment were type 2 inflammatory markers such as exhaled nitric oxide fraction and blood eosinophils.
“It’s time for the guidelines to sit on the sidelines,’ he said.
“Patients want to know what works and we can be more objective and systematic about that by using these tools, in preference to a trial and error approach.”