Dataset Information

Effect of inhaled dust mite allergen on regional particle deposition and mucociliary clearance in allergic asthmatics.

ABSTRACT: Acute exacerbations in allergic asthmatics may lead to impaired ability to clear mucus from the airways, a key factor in asthma morbidity.The purpose of this study was to determine the effect of inhaled house dust mite challenge on the regional deposition of inhaled particles and mucociliary clearance (MCC) in allergic asthmatics.We used gamma scintigraphy (inhalation of (99m) Tc -sulphur colloid particles) to measure the regional particle deposition and MCC in allergic asthmatics (n=12) 4 h following an inhaled dust mite allergen challenge (Dermatophagoides farinae extract; PD(max) =fall in forced expiratory volume in 1 s of 10%) for comparison with baseline non-challenge measures.In responders (n=9 PD(max) dose), lung function returned to pre-challenge values by 3 h but was significantly decreased at 6 and 24 h in three of the responders (i.e. late-phase response) and induced sputum eosinophils were increased at 24 h post-challenge (P<0.05). Responders showed enhanced bronchial airway deposition of inhaled particles (P<0.05) and slowed clearance from the central lung zone (P<0.01) at 4 h post-challenge compared with the baseline (no allergen challenge) that was predicted by the PD(max) allergen concentration (r=-0.70, P<0.05). The decline in lung function at 24 h post-challenge correlated with reduced MCC from the central lung zone (r=-0.78, P<0.02) and PD(max) . Non-responders (n=3) showed no change in lung function, regional deposition or MCC post-challenge vs. baseline.These data suggest that regional deposition and clearance of inhaled particles may be sensitive for detecting mild airway obstruction associated with early- and late-phase allergen-induced effects on mucus secretions. The study was listed on clinicaltrials.gov (NCT00448851).

SUBMITTER: Bennett WD

PROVIDER: S-EPMC3750994 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Effect of inhaled dust mite allergen on regional particle deposition and mucociliary clearance in allergic asthmatics.

Bennett W D WD Herbst M M Alexis N E NE Zeman K L KL Wu J J Hernandez M L ML Peden D B DB

Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology 20110705 12

<h4>Background</h4>Acute exacerbations in allergic asthmatics may lead to impaired ability to clear mucus from the airways, a key factor in asthma morbidity.<h4>Objective</h4>The purpose of this study was to determine the effect of inhaled house dust mite challenge on the regional deposition of inhaled particles and mucociliary clearance (MCC) in allergic asthmatics.<h4>Methods</h4>We used gamma scintigraphy (inhalation of (99m) Tc -sulphur colloid particles) to measure the regional particle dep ...[more]

PMID: 21729182

Similar Datasets

Project description:BackgroundAllergen immunotherapy (AIT) is a specific treatment of administering clinically important allergens to patients who have allergic diseases. In Japan, the standardized house dust mite (HDM) allergen for subcutaneous immunotherapy (SCIT) was approved in 2015, and we then introduced rush-immunotherapy (rush-IT) using the standardized HDM allergen for HDM-sensitive asthmatics. However, little data are available on the safety and effectiveness of rush-HDM-IT, especially for Japanese asthmatics.ObjectiveThe objective of this study was to examine the safety and clinical effectiveness of rush-IT using the standardized HDM for HDM-sensitive Japanese asthmatics.MethodsThirteen HDM-sensitive asthmatics who received rush-HDM-IT and 12 HDM-sensitive asthmatic controls were enrolled. To evaluate the safety, the number of systemic reaction (SR) events, including anaphylaxis, was assessed. To evaluate the effectiveness, changes in the treatment step, dose of inhaled corticosteroid, and asthma control after rush-HDM-IT and the subsequent maintenance SCIT were assessed. Changes in the HDM-induced production of type 2 cytokines from peripheral blood mononuclear cells were also evaluated.ResultsAmong the 12 patients who received rush-IT, 4 (30.7%) experienced a SR and 3 (23.1%) experienced anaphylaxis. However, the anaphylaxis was not severe (grade 3) in all cases, and they recovered in a short time. The treatment step of asthma was better and the dose of inhaled corticosteroid was lower in the rush-HDM-IT group than in the control group. The HDM-induced production of both interleukin (IL)-5 and IL-13 from peripheral blood mononuclear cells was significantly lower in the rush-HDM-IT group than in the control group.ConclusionRush-HDM-IT can be performed relatively safely in Japanese asthmatics. Furthermore, rush-HDM-IT and the subsequent maintenance SCIT provided clinical improvement in asthma patients, and was accompanied by the suppression of HDM-specific Th2-mediated systemic immune responses.

Project description:BackgroundInhaled allergen challenge is a validated disease model of allergic asthma offering useful pharmacodynamic assessment of pharmacotherapeutic effects in a limited number of subjects.ObjectivesTo evaluate whether an RNA signature can be identified from induced sputum following an inhaled allergen challenge, whether a RNA signature could be modulated by limited doses of inhaled fluticasone, and whether these gene expression profiles would correlate with the clinical endpoints measured in this study.MethodsThirteen non-smoking, allergic subjects with mild-to-moderate asthma participated in a randomised, placebo-controlled, 2-period cross-over study following a single-blind placebo run-in period. Each period consisted of three consecutive days, separated by a wash-out period of at least 3 weeks. Subjects randomly received inhaled fluticasone ((FP) MDI; 500 mcg BID×5 doses in total) or placebo. On day 2, house dust mite extract was inhaled and airway response was measured by FEV1 at predefined time points until 7 h post-allergen. Sputum was induced by NaCl 4.5%, processed and analysed at 24 h pre-allergen and 7 and 24 h post-allergen. RNA was isolated from eligible sputum cell pellets (<80% squamous of 500 cells), amplified according to NuGEN technology, and profiled on Affymetrix arrays. Gene expression changes from baseline and fluticasone treatment effects were evaluated using a mixed effects ANCOVA model at 7 and at 24 h post-allergen challenge.ResultsInhaled allergen-induced statistically significant gene expression changes in sputum, which were effectively blunted by fluticasone (adjusted p<0.025). Forty-seven RNA signatures were selected from these responses for correlation analyses and further validation. This included Th2 mRNA levels for cytokines, chemokines, high-affinity IgE receptor FCER1A, histamine receptor HRH4, and enzymes and receptors in the arachidonic pathway. Individual messengers from the 47 RNA signatures correlated significantly with lung function and sputum eosinophil counts.ConclusionOur RNA extraction and profiling protocols allowed reproducible assessments of inflammatory signatures in sputum including quantification of drug effects on this response in allergic asthmatics. This approach offers novel possibilities for the development of pharmacodynamic (PD) biomarkers in asthma.

Dataset Information

Effect of inhaled dust mite allergen on regional particle deposition and mucociliary clearance in allergic asthmatics.

Publications

Effect of inhaled dust mite allergen on regional particle deposition and mucociliary clearance in allergic asthmatics.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets