Bronchodilator Responsiveness Measured by Spirometry and Impulse Oscillometry in Patients with Asthma After Short Acting Antimuscarinic and/or Beta-2-Agonists Inhalation.

Background: Bronchodilator responsiveness (BDR) in asthma involves both the central and peripheral airways but is primarily relieved with beta-2-agonists and evaluated by spirometry. To date, antimuscarinics can be added as a reliever medication in more severe asthma. We hypothesize that combining both short-acting beta-2 agonist (SABA) and short-acting muscarinic antagonist (SAMA) could also improve the responsiveness in mild-moderate asthma. Therefore, we aimed to compare the direct effects of inhaling SABA alone, SAMA alone or combining both SABA and SAMA on the central and peripheral airways in asthma. Methods: Twenty-three patients with mild-moderate BDR in asthma performed dynamic spirometry and impulse oscillometry before (baseline) and multiple timepoints within an hour after inhalation of SABA (salbutamol), SAMA (ipratropium bromide), or both SABA and SAMA at three different visits. Results: The use of SAMA alone did not show any improvement compared to the use of SABA alone. Inhalation of SABA+SAMA, however, averaged either similar or better BDR than SABA alone in FEV1, MMEF, FVC, R5, R20 and R5-R20. Inhaling SABA+SAMA reached a stable BDR in more patients within 0-10 minutes and also reached the FEV1 (Δ%)>12% faster (3.5 minutes) than inhaling SABA alone (5.1 minutes). Inhaling SABA+SAMA was significantly better than SAMA alone in FEV1 (p = 0.015), MMEF (p = 0.0059) and R20 (p = 0.0049). Using these three variables highlighted a subgroup (30%, including more males) of patients that were more responsive to inhaling SABA+SAMA than SABA alone. Conclusion: Overall, combining SAMA with SABA was faster and more consistent at increasing the lung function than SABA alone or SAMA alone, and the additive effect was best captured by incorporating peripheral-related variables. Therefore, SAMA should be considered as an add-on reliever for mild-moderate patients with BDR in asthma.

Lung Fibroblasts from Chronic Obstructive Pulmonary Disease Subjects Have a Deficient Gene Expression Response to Cigarette Smoke Extract Compared to Healthy.

Background and aim: Cigarette smoking is the most common cause of chronic obstructive pulmonary disease (COPD) but more mechanistic studies are needed. Cigarette smoke extract (CSE) can elicit a strong response in many COPD-related cell types, but no studies have been performed in lung fibroblasts. Therefore, we aimed to investigate the effect of CSE on gene expression in lung fibroblasts from healthy and COPD subjects. Patients and methods: Primary lung fibroblasts, derived from six healthy and six COPD subjects (all current or ex-smokers), were either unstimulated (baseline) or stimulated with 30% CSE for 4 h prior to RNA isolation. The mRNA expression levels were measured using the NanoString nCounter Human Fibrosis V2 panel (760 genes). Pathway enrichment was assessed for unique gene ontology terms of healthy and COPD. Results: At baseline, a difference in the expression of 17 genes was found in healthy and COPD subjects. Differential expression of genes after CSE stimulation resulted in significantly less changes in COPD lung fibroblasts (70 genes) than in healthy (207 genes), with 51 genes changed in both. COPD maintained low NOTCH signaling throughout and upregulated JUN >80%, indicating an increase in apoptosis. Healthy downregulated the Mitogen-activated protein kinase (MAPK) signaling cascade, including a ≥50% reduction in FGF2, CRK, TGFBR1 and MEF2A. Healthy also downregulated KAT6A and genes related to cell proliferation, all together indicating possible cell senescence signaling. Conclusion: Overall, COPD lung fibroblasts responded to CSE stimulation with a very different and deficient expression profile compared to healthy. Highlighting that stimulated healthy cells are not an appropriate substitute for COPD cells which is important when investigating the mechanisms of COPD.

A low inflammatory, Langerhans cell-targeted microprojection patch to deliver ovalbumin to the epidermis of mouse skin.

In a low inflammatory skin environment, Langerhans cells (LCs) - but not dermal dendritic cells (dDCs) - contribute to the pivotal process of tolerance induction. Thus LCs are a target for specific-tolerance therapies. LCs reside just below the stratum corneum, within the skin's viable epidermis. One way to precisely deliver immunotherapies to LCs while remaining minimally invasive is with a skin delivery device such as a microprojection arrays (MPA). Today's MPAs currently achieve rapid delivery (e.g. within minutes of application), but are focussed primarily at delivery of therapeutics to the dermis, deeper within the skin. Indeed, no MPA currently delivers specifically to the epidermal LCs of mouse skin. Without any convenient, pre-clinical device available, advancement of LC-targeted therapies has been limited. In this study, we designed and tested a novel MPA that delivers ovalbumin to the mouse epidermis (eMPA) while maintaining a low, local inflammatory response (as defined by low erythema after 24 h). In comparison to available dermal-targeted MPAs (dMPA), only eMPAs with larger projection tip surface areas achieved shallow epidermal penetration at a low application energy. The eMPA characterised here induced significantly less erythema after 24 h (p = 0.0004), less epidermal swelling after 72 h (p < 0.0001) and 52% less epidermal cell death than the dMPA. Despite these differences in skin inflammation, the eMPA and dMPA promoted similar levels of LC migration out of the skin. However, only the eMPA promoted LCs to migrate with a low MHC II expression and in the absence of dDC migration. Implementing this more mouse-appropriate and low-inflammatory eMPA device to deliver potential immunotherapeutics could improve the practicality and cell-specific targeting of such therapeutics in the pre-clinical stage. Leading to more opportunities for LC-targeted therapeutics such as for allergy immunotherapy and asthma.