RESUMEN
Chronic obstructive pulmonary disease (COPD) refers to a group of widely diffuse diseases that cause airflow blockage characterized by persistent respiratory symptoms such as dyspnea, chronic cough, recurrent wheezing, chronic sputum production, and progressive restricted airflow associated with exacerbations. COPD is the third leading cause of death worldwide and can only be treated not cured. Pulmonary function tests do not permit the identification of initial obstructive airways disease. Forced expiratory flow (FEF25-75), which calculates obstruction severity at small and medium bronchial airways levels, allows an early COPD diagnosis. We report a 72-year-old ex-smoker male not exposed to occupational risk with symptoms suggesting early COPD. Baseline pulmonary function tests were normal, except FEF25-75. The patient did not respond to the first 6 months of treatment with long-acting muscarinic antagonist (LAMA), whereas he showed a clear clinical and FEF25-75 response to 1-year treatment with LAMA associated with long-acting ß2 agonist (LABA). This clinical case report highlights the usefulness of FEF25-75 evaluation in early COPD diagnosis and monitoring and confirms the efficacy of LAMA-LABA association for small airways obstruction treatment.
RESUMEN
The small airways dysfunction (SAD) asthma phenotype is characterised by narrowing of airways < 2 mm in diameter between generations 8 and 23 of the bronchial tree. Recently, this has become particularly relevant as measurements of small airways using airway oscillometry for example, are strong determinants of asthma control and exacerbations in moderate-to-severe asthma. The small airways can be assessed using spirometry as forced expiratory flow rate between 25 and 75% of forced vital capacity (FEF25-75) and has been deemed more accurate in detecting small airways dysfunction than forced expiratory volume in 1 s (FEV1). Oscillometry as the heterogeneity in resistance between 5 and 20 Hz (R5-R20), low frequency reactance at 5 Hz (X5) or area under the reactance curve between 5 Hz and the resonant frequency can also be used to assess the small airways. The small airways can also be assessed using the multiple breath nitrogen washout (MBNW) test giving rise to values including functional residual capacity, lung clearance index and ventilation distribution heterogeneity in the conducting (Scond) and the acinar (Sacin) airways. The ATLANTIS group showed that the prevalence of small airways disease in asthma defined on FEF25-75, oscillometry and MBNW all increased with progressive GINA asthma disease stages. As opposed to topical inhaler therapy that might not adequately penetrate the small airways, it is perhaps more intuitive that systemic anti-inflammatory therapy with biologics targeting downstream cytokines and upstream epithelial anti-alarmins may offer a promising solution to SAD. Here we therefore aim to appraise the available evidence for the effect of anti-IgE, anti-IL5 (Rα), anti-IL4Rα, anti-TSLP and anti-IL33 biologics on small airways disease in patients with severe asthma.