Distinguishing adult-onset asthma from COPD: a review and a new approach

Abstract

Adult-onset asthma and chronic obstructive pulmonary disease (COPD) are major public health burdens. This review presents a comprehensive synopsis of their epidemiology, pathophysiology, and clinical presentations; describes how they can be distinguished; and considers both established and proposed new approaches to their management. Both adult-onset asthma and COPD are complex diseases arising from gene–environment interactions. Early life exposures such as childhood infections, smoke, obesity, and allergy influence adult-onset asthma. While the established environmental risk factors for COPD are adult tobacco and biomass smoke, there is emerging evidence that some childhood exposures such as maternal smoking and infections may cause COPD. Asthma has been characterized predominantly by Type 2 helper T cell (Th2) cytokine-mediated eosinophilic airway inflammation associated with airway hyperresponsiveness. In established COPD, the inflammatory cell infiltrate in small airways comprises predominantly neutrophils and cytotoxic T cells (CD8 positive lymphocytes). Parenchymal destruction (emphysema) in COPD is associated with loss of lung tissue elasticity, and small airways collapse during exhalation. The precise definition of chronic airflow limitation is affected by age; a fixed cut-off of forced expiratory volume in 1 second/forced vital capacity leads to overdiagnosis of COPD in the elderly. Traditional approaches to distinguishing between asthma and COPD have highlighted age of onset, variability of symptoms, reversibility of airflow limitation, and atopy. Each of these is associated with error due to overlap and convergence of clinical characteristics. The management of chronic stable asthma and COPD is similarly convergent. New approaches to the management of obstructive airway diseases in adults have been proposed based on inflammometry and also multidimensional assessment, which focuses on the four domains of the airways, comorbidity, self-management, and risk factors. Short-acting beta-agonists provide effective symptom relief in airway diseases. Inhalers combining a long-acting beta-agonist and corticosteroid are now widely used for both asthma and COPD. Written action plans are a cornerstone of asthma management although evidence for self-management in COPD is less compelling. The current management of chronic asthma in adults is based on achieving and maintaining control through step-up and step-down approaches, but further trials of back-titration in COPD are required before a similar approach can be endorsed. Long-acting inhaled anticholinergic medications are particularly useful in COPD. Other distinctive features of management include pulmonary rehabilitation, home oxygen, and end of life care.

Systematic Review of Telemonitoring in COPD: An Update

“…The clinical course is characterized by progressive decline in health status, punctuated by acute respiratory exacerbations [1]. These exacerbations have a negative impact on patient prognosis, with progressive disability and increased health care resource use [2,3].…”

Fatores associados à Doença Pulmonar Obstrutiva Crônica em idosos

“…Asthma is not uncommon in elderly people being either a reoccurrence of a childhood disease or one which appear later on in life. The search for information on the progressive history of asthma, atopy, triggering factors, responses to corticosteroids and the reversal of the obstruction of the air flow after the application of the bronchodilator test in the spirometry has produced data that corroborates in the presence of asthma amongst the elderly 2,30 . Recent studies highlight the difficulties of making a distinction between asthma and COPD in relation to smokers and ex-smoker 30,31 .…”

“To define is to limit”: perspectives on asthma–COPD overlap syndrome and personalised medicine

“…COPD and asthma are both heterogeneous diseases. In both diseases there is an overlap of airway inflammatory granulocytes, in both conditions patients may be atopic and hyperresponsive, and a reasonable proportion of patients with asthma have a smoking history [22]. Given the limitations of different definitions, is it necessary to define the overlap of features as a new disease entity?…”