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
Microbes and asthma: “old friends” may offer opportunities for intervention
Asthma is an umbrella term for different phenotypes or endotypes, which arise through different pathophysiologic pathways. Microbes have developed mechanisms to manipulate the human immune system during their coevolution with people. The background of the so called “old friends” hypothesis which is an extension of the hygiene hypothesis. The “old friends” are a group of microbes which the human race has coevolved and that in the past 50 years were rapidly lost because of changes in lifestyle, living conditions, or occupations. This article investigates how modulation of the immune system by bacterial, parasitic, and viral infections might affect the development of asthma.
Source: Smits HH, Hiemstra PS, Prazeres da Costa C, Ege M, Edwards M et al. Microbes and asthma: Opportunities for intervention. Journal of Allergy and Clinical Immunology 2016; 137(3): 690–697. (10.1016/j.jaci.2016.01.004)
Image Source: Wikipedia, Staphylococcus aureus, public domain
Improvements in impulse oscillometry after chronic dosing with formoterol compared with salmeterol might reflect better deposition to small airways
Effects of small-particle long-acting beta-agonists on the small airways have been poorly documented. This study used impulse oscillometry (IOS) to compare single and repeated dosing effects of small- (formoterol MDI) and large-particle (salmeterol DPI) long-acting beta-agonists.
Sixteen patients received either formoterol or salmeterol twice daily plus inhaled corticosteroid for 1 to 2 weeks with a 1- to 2-week washout period in between (mean age, 43 years; FEV1, 80%, FEF25-75, 48%).
There were greater improvements with formoterol versus salmeterol in all IOS outcomes but not FEV1.
Significant improvements in IOS outcomes but not spirometry results occurred after chronic dosing with formoterol compared with salmeterol. This might reflect better deposition to the entire lung, including the small airways.
Source: Manoharan A, von Wilamowitz-Moellendorff A, Morrison A, Lipworth BJ. Effects of formoterol or salmeterol on impulse oscillometry in patients with persistent asthma. Journal of Allergy and Clinical Immunology 2016; 137(3): 727–733. (doi:10.1016/j.jaci.2015.06.012)
60% of elderly patients with asthma have rhinitis, mainly allergic and often untreated, whose onset preceded asthma symptoms by 10 years
This study from Italy investigated the role of rhinitis and sensitization to airborne allergens in 368 elderly patients with asthma (65 years and older). Approximately 30% of patients had some features of overlapping COPD. Skin prick tests for common allergens were performed.
Rhinitis was present in 59% of patients, with an age of onset significantly different from that of asthma (49 for rhinitis vs 57 years for asthma). At least one sensitization was observed in 52% of subjects, more frequently for house dust mite (HDM; 31.8%).
The prevalence of poorly and partially controlled asthma was higher in patients sensitized to airborne allergens (odds ratio 1.64), in particular to HDM (odds ratio 1.73).
Approximately 60% of elderly subjects with asthma had rhinitis, mainly allergic and often untreated, whose onset preceded asthma symptoms by a mean of approximately ten years. HDM sensitization was greater in patients with asthma with features resembling COPD (39% vs 28%).
Nonallergic asthma was better controlled than allergic asthma.
Source: Lombardi C, Raffetti E, Caminati M, Liccardi G, Passalacqua G et al. Phenotyping asthma in the elderly: allergic sensitization profile and upper airways comorbidity in patients older than 65 years. Annals of Allergy, Asthma and Immunology 2016; 116(3): 206–211. (doi:10.1016/j.anai.2015.12.005)