What Is New In Small Airways Research
Ves Dimov, MD
Allergist/Immunologist at Cleveland Clinic
Clinical Associate Professor
FAU Charles E. Schmidt College of Medicine
Small-airway obstruction, assessed based on FEF25-75, contributes to long-term persistence of asthma and poor outcomes
The aim of this study assess if forced midexpiratory flow between 25% and 75% of forced vital capacity (FEF25-75) was associated with the persistence of current asthma over 20 years and the subsequent risk for uncontrolled asthma independently of FEV1.
The Epidemiological Study on the Genetics and Environment of Asthma (EGEA1) included 337 patients (142 children and 225 adults) with asthma (defined as asthma attacks or treatment in the past 12 months). They were followed with 12- and 20-year surveys. Persistent asthma was defined by asthma reported at each survey. A lung function test and a methacholine challenge test were performed at EGEA1 and EGEA2.
A reduced level of FEF25-75 at EGEA1 increased the risk of long-term asthma persistence but only slightly (adjusted OR, 1.14), it was also associated with more severe bronchial hyperresponsiveness and with asthma a decade later (adjusted OR, 1.21 to 1.44).
Source: Siroux V, Boudier A, Dolgopoloff M, Chanoine S, Bousquet J et al. Forced midexpiratory flow between 25% and 75% of forced vital capacity is associated with long-term persistence of asthma and poor asthma outcomes. Journal of Allergy and Clinical Immunology 2016; 137(6): 1709-1716. (doi:10.1016/j.jaci.2015.10.029)
Image Source: Creative Commons Attribution, Flow volume loop, Unported license.
Meta-analysis of once-daily fluticasone furoate and vilanterol for adolescents and adults with asthma: no difference between 200/25 μg and 100/25 μg doses
Fluticasone furoate and vilanterol is a new inhaled corticosteroid (ICS) and long-acting β2-agonist (LABA) combination developed for once-daily administration via a dry powder inhaler.
This meta-analysis included 7 RCTs with 5,668 patients.
Fluticasone furoate–vilanterol was associated with increases in FEV1 and PEF compared with fluticasone furoate, 100 μg, monotherapy. Fluticasone furoate–vilanterol reduced the rate of severe asthma exacerbations (number need to treat for benefit = 24). Fluticasone furoate–vilanterol also increases FEV1 and PEF compared with fluticasone propionate, 500 μg twice daily.
Fluticasone furoate–vilanterol had a nonsignificant increase in the frequency of cardiac events (6.4% vs 1.8%) compared with fluticasone propionate. No differences were found between both available doses of fluticasone furoate–vilanterol (200/25 μg and 100/25 μg) in terms of efficacy. However, patients receiving fluticasone furoate–vilanterol, 200/25 μg, had a trend toward an increased risk of cardiac events.
Studies comparing fluticasone furoate–vilanterol with fixed twice-daily ICS-LABA combinations are required.
Source: Rodrigo GJ and Plaza V. Once-daily fluticasone furoate and vilanterol for adolescents and adults with symptomatic asthma. Annals of Allergy, Asthma and Immunology 2016; 116(6): 565–570. (doi:10.1016/j.anai.2016.03.035)
Asthmatic patients have a prothrombotic state that increases with asthma severity
This study compared coagulation and fibrinolysis parameters between healthy subjects and patients with mild, severe, and prednisolone-dependent. The study was relatively small, it included 31 patients with mild asthma, 32 patients with severe asthma, and 30 patients with prednisolone-dependent asthma.
There were increases in endogenous thrombin potential [ETP], plasmin-α2-antiplasmin complex, plasminogen activator inhibitor type 1 [PAI-1]), and von Willebrand factor [vWF]. ETP, PAI-1, and vWF levels increased with increasing asthma severity.
The study authors concluded that asthmatic patients have a prothrombotic state that increases with asthma severity. This might explain why patients with asthma, in particular those with severe disease, have an increased risk of venous thromboembolism.
Source: Sneeboer MMS, Majoor CJ, de Kievit A, Meijers JCM, van der Poll T, Kamphuisen PW, Bel EH. Prothrombotic state in patients with severe and prednisolone-dependent asthma. Marlous M.S. Journal of Allergy and Clinical Immunology 2016; 137(6): 1727–1732. (doi:10.1016/j.jaci.2015.10.038)