Resumo

LOPEZ, Ana M et al. Asthma-COPD Overlap: Findings of the EPOC.AR Study. Rev. am. med. respir. [online]. 2022, vol.22, n.2, pp.125-133. ISSN 1852-236X.

Background: Asthma and COPD are heterogeneous diseases, and some patients share clinical features of both conditions. There are uncertainties about the criteria to define asthma-COPD overlap (ACO), and its prevalence is 15-25% in the adult population with chronic airflow obstruction. The purpose of this study was to determine the prevalence of ACO in Argentina, which is unknown.

Objectives: Primary: to determine the prevalence of ACO in the EPOC.AR study. Secondary: to evaluate and analyze the clinical features of patients with ACO, the severity of the symptoms, and the frequency and severity of exacerbations. to describe and compare the treatment of ACO with that of pure COPD.

Database of the EPOC.AR study: spirometries, asthma, atopy or rhinitis, respiratory symptoms: CAT (COPD Assesment Test) and mMRC (Modified Medical Research Council) scale, frequency of exacerbations/previous year, comorbidities and treatments. 2017 GOLD Guides (Global Initiative for Chronic Obstructive Lung Disease) to determine airflow obstruction degrees and Groups A, B, C, and D.

ACO diagnostic criteria (expert committee from USA, East Europe and Asia that took place in Denver, 2015):

MAJOR CRITERIA: 1. Persistent obstruction (post-BD [bronchodilator] FEV1/FVC (forced expiratory volume in the first second/forced vital capacity) < 70% or LLN [lower limit of normal] ) in ≥ 40 years. 2. SM (smoking) ≥ 10 packs/year, air pollution or biomass. 3. Documented history of asthma before 40 years or post-BD response ≥ 400 ml in FEV1.

MINOR CRITERIA: 1. Documented history of atopy or allergic rhinitis. 2. Post-BD response in FEV1 > 200 ml. 3. Peripheral blood eosinophil count ≥ 300 cells-Ul-1 (not performed in EPOC.AR).

Chi-Square Test, Pearson’s Chi Square Test, likelihood ratio, linear-by-linear association.

Results: COPD (n 498), n 95 with ACO criteria, males (53.4%), mean age 63.6 years.

1% without asthma and BD response ≥ 400 ml; 32.7% asthmatics (3.6% with BD response ≥ 400 ml and 14.5% between 200-400 ml); n 23 with BD response ≥ 400 ml (4.6%). ACO prevalence: 19.08% (CI [Confidence Interval] 15.6-22.5) and 2.6% of the total population of EPOC.AR. In the comparison between the ACO and COPD populations, we detected the following: lower mean age and pre-BD FEV1 (p < 0.01), higher frequency of BD response (p < 0.05), higher frequency of sibilance (p < 0.01; CI 2.75-7.64), higher frequency of previous asthma diagnosis (p < 0.01; CI 3.79-10.05); and 26.08% had family history of asthma. Greater use of ATBs (antibiotics) (p < 0.05) and ICS (inhaled corticosteroids)/ LABA (long-acting beta- adrenergic agonists) (p < 0.05; CI 1.1-5.3). Higher frequency of exacerbations (12.47%; CI 9.56-15.39) that motivated the indication of medication in 90.48% and 2.49 times more alterations in daily activities and absence from work.

There weren’t any significant differences between patients with ACO and pure COPD regarding frequency of groups A, B, C and D.

Conclusions: the prevalence of ACO was 19.08% in the COPD patients of the EPOC. AR study; they were significantly younger, with higher degree of obstruction, frequency of sibilance, use of antibiotics/previous year and inhaled corticosteroids (LABA/IC). We emphasize the importance of identifying this phenotype in order to use a suitable treat ment, given its clinical implications and deterioration in quality of life.

Palavras-chave : Asthma; Pulmonary Disease; Chronic Obstructive; Smoking.

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