Asthma-COPD overlap syndrome: pathogenesis, clinical features, and therapeutic targets

Abstract

Asthma-COPD overlap syndrome (ACOS) or asthma-COPD overlap captures the subset of patients with airways disease who have features of both asthma and chronic obstructive pulmonary disease (COPD). Although definitions of ACOS vary, it is generally thought to encompass persistent airflow limitation in a patient older than 40 years of age with either a history of asthma or large bronchodilator reversibility. ACOS affects about a quarter of patients with COPD and almost a third of patients who previously had asthma. Compared with their counterparts with asthma or COPD alone, patients with ACOS have significantly worse respiratory symptoms, poorer quality of life, and increased risk of exacerbations and hospital admissions. Whether this condition emerges after gradual shifts in airway remodelling and inflammation in a patient with COPD, as the result of noxious exposures in a patient with asthma, or even as a de novo disease with its own pathology is yet to be determined. Nevertheless, using treatments developed for asthma or COPD that target eosinophilic, neutrophilic, or paucigranulocytic airway inflammation may be a helpful approach to these patients until further clinical trials can be performed.

Impulse oscillometry at preschool age is a strong predictor of lung function by flow‐volume spirometry in adolescence

“…The children with a history of severe bronchiolitis often present with early wheezing symptoms, and seem to be at risk of having long‐term lung function deficit, resembling chronic obstructive lung disease in adulthood . Whether some of these children develop an asthma‐COPD overlap syndrome, is yet to be defined. However, this group of children with early‐onset childhood wheezing phenotype drops out of regular follow‐ups, as their symptoms remit by school age .…”

Does Vitamin D3 supplementation affect antioxidant enzymes of D3 deficient patients with asthma COPD overlap (ACO)? - A randomized controlled trial

“…Approximately one in four patients with COPD have asthmatic features consist of wheeze, airway hyperresponsiveness or atopy 3 . On the other hand, patients with asthma may present with fixed airway obstruction over time 4 . In 2015, a joint project GINA and global standard of obstructed lung disease(GOLD) described ACO as, persistent airflow limitation with several features usually associated with asthma and several features usually associated with COPD 5 .…”

Clinical Pharmacology of Bronchodilator Medications

“…Those patients who demonstrate elements of fixed air-flow obstruction and reversible air-flow obstruction with triggering factors may have the asthma-COPD overlap syndrome. 48 It is likely that these patients will be more responsive to bronchodilators than those with so-called pure COPD. Nonetheless, one study demonstrated that Ͼ 50% of COPD subjects (without an asthma component) demonstrated a significant bronchodilator response on spirometry.…”