Chest
Recent Advances in Chest MedicineClinical Approach to the Therapy of Asthma-COPD Overlap
Section snippets
Why Has ACO Become a Renewed Focus of Interest?
Asthma and COPD have been recognized now for centuries. The potential for overlap has been well described, and the concept that asthma and COPD share common origins was conceived more than half a century ago.15 Why then has there been an increased interest in this subgroup of patients in recent years? This may reflect an increased attention to disease phenotyping because precision medicine approaches require more refined understanding of disease heterogeneity. Along with this is the combination
Management Strategies for Asthma, COPD, and ACO
The Global Strategy for Asthma Management and Prevention and the Global Strategy for the Diagnosis, Management, and Prevention of COPD19 provided approaches for the diagnosis and management of ACO. However, these approaches were based mainly on expert opinion rather than patient outcomes data, reflecting an overall need for well-designed studies that address the management of this population. Nevertheless, these strategies provide a starting point for clinicians who encounter these patients in
Contrasting Therapies of Asthma and COPD in Mild/Moderate Disease
Inhaled medications are the foundation of therapy for both asthma and COPD. The treatment of these diseases uses a stepwise or escalation approach based on symptoms and exacerbations.22, 23 However, there is a key distinction between both treatment algorithms: specifically, the introduction of inhaled corticosteroids (ICSs) (Fig 1). In asthma, ICSs are introduced early in the treatment for patients who are symptomatic. ICSs decrease the risk of severe exacerbations, improve asthma control, and
Contrasting Therapies of Asthma and COPD in Severe Disease
Both severe asthma and COPD are characterized by worsening respiratory symptoms, frequent exacerbations and increased health-care utilization.47, 48 In these advanced stages, the treatment may require triple therapy with ICS, LABA, and LAMA (Fig 1). In COPD, triple therapy has been shown to improve lung function and exacerbation rates without increasing adverse events compared with dual therapy and placebo.49, 50, 51 For instance, a recent study by Vestbo et al52 showed that triple therapy
Role of Biomarkers in ACO
The use of biomarkers to identify patients who may benefit from therapy is well established in asthma.55, 56 In COPD, this method has accumulating evidence of benefits.60, 61 Although this approach might appear to be particularly useful to identify the ACO population, to date there is no biomarker that best encompasses the biologic mechanisms of this overlap. In fact, evidence suggests that ACO is a heterogeneous group encompassing several phenotypes of disease, including both eosinophilic and
Therapeutic Guidance
In patients with ACO who remain symptomatic despite inhaled therapies, an in-depth evaluation is required to determine the presence of treatable traits, which may aid in the diagnosis and provide therapeutic guidance.46 Further work is needed to help clinicians select the most appropriate therapy. Predictors of response in chronic airways disease is an area of intense research. Elevated serum levels of IgE, exhaled fraction of nitric oxide, and peripheral blood eosinophilia not only provide
Conclusions
There is still much to learn about the spectrum of ACO. Because asthma and COPD are inherently heterogeneous, future studies that include well-characterized and richly phenotyped cohorts of patients with features of both asthma and COPD, with varying degrees of severity and exacerbation history, are needed to better study disease interactions, risk factors, and prognostic makers.89 A gap clearly exists in the evidence for therapy in ACO, particularly in severe disease. Nevertheless, in clinical
Acknowledgments
Authors contributions: D. J. M. is the guarantor of this article. D. J. M. and F. J. M. contributed to conception, manuscript writing, and manuscript review. M. H. and S. A. C. contributed to manuscript writing and manuscript review. N. A. H., S. G. A, A. A., J. I. P., and M. K. H. contributed to interpretation of data and critical revisions. C. P. H. contributed to interpretation of data and critical revisions.
Financial/nonfinancial disclosures: The authors have reported to CHEST the
References (89)
- et al.
Mortality trends in chronic obstructive pulmonary disease in Europe, 1994-2010: a joinpoint regression analysis
Lancet Respir Med
(2014) - et al.
Understanding asthma-chronic obstructive pulmonary disease overlap syndrome
Respir Med
(2016) - et al.
The asthma-COPD overlap syndrome: towards a revised taxonomy of chronic airways diseases?
Lancet Respir Med
(2015) - et al.
Increased risk of exacerbation and hospitalization in subjects with an overlap phenotype: COPD-asthma
Chest
(2014) - et al.
Early intervention with budesonide in mild persistent asthma: a randomised, double-blind trial
Lancet
(2003) - et al.
Effects of early intervention with inhaled budesonide on lung function in newly diagnosed asthma
Chest
(2006) - et al.
The Salmeterol Multicenter Asthma Research Trial: a comparison of usual pharmacotherapy for asthma or usual pharmacotherapy plus salmeterol
Chest
(2006) - et al.
Cardiovascular safety of tiotropium in patients with COPD
Chest
(2010) - et al.
Benefits of adding fluticasone propionate/salmeterol to tiotropium in moderate to severe COPD
Respir Med
(2012) - et al.
Comparison of tiotropium plus fluticasone propionate/salmeterol with tiotropium in COPD: a randomized controlled study
Respir Med
(2012)