Experts have called for a broader definition of COPD and a rethink on its classification to help advance prevention, spur the development of novel therapies, improve its clinical management, and set the course for disease elimination.
A Lancet Commission headed by Professor Daiana Stolz , Chair of the ERS Education Council, suggests a much broader definition of COPD than spirometric airflow limitation, which essentially eliminates the possibility of cure as the pathological changes necessary to show “are almost certainly permanent”.
As such, the group has endorsed a much broader definition that includes people with airflow limitation “detected by more sensitive pulmonary function tests or pathological changes detected by imaging techniques”.
“This broader definition will enable detection of patients with earlier pathological changes, which would enhance the possibility of understanding the mechanistic pathways driving disease inception and could thus lead to the development of effective treatments to interrupt and reverse the course of COPD,” according to to the paper.
“We recognise that the risks factors leading to airflow limitation are numerous, and that many patients are affected by more than one. However, this is also true for patients with pulmonary hypertension, who can have more than one mechanism driving their disease (eg, heart failure and coexistent lung disease),” the authors noted.
“Our proposal is not perfect and, like the WHO classification of pulmonary hypertension, will require iterative refinement, but it is far more likely to yield new therapeutics than a system that relies solely on the presence of spirometric airflow limitation and a patient’s level of dyspnoea and exacerbation frequency (the extent of current attempts to classify COPD)”.
The Commission also proposed a new classification system for COPD, comprised of five different subtypes categorised by the predominant risk factors causing the disease: genetically determined disease (type 1); COPD related to early-life events (type 2); infection-related COPD (type 3); COPD related to smoking or vaping (type 4); and environmental exposure-related COPD (type 4).
“Guidelines recommend only simplistic disease classification strategies, resulting in the same therapeutic approach for patients with widely differing conditions that are almost certainly driven by variable pathophysiological mechanisms,” they said.