Effects of treatment changes on asthma phenotype prevalence and airway neutrophil function.

Background: Asthma inflammatory phenotypes are often defined by relative cell counts of airway eosinophils/neutrophils. However, the importance of neutrophilia remains unclear, as does the effect of ICS treatment on asthma phenotypes and airway neutrophil function. The purpose of this study was to assess asthma phenotype prevalence/characteristics in a community setting, and, in a nested preliminary study, determine how treatment changes affect phenotype stability and inflammation, with particular focus on airway neutrophils.

Absence of airway inflammation in a large proportion of adolescents with asthma.

Background And Objective: Neutrophilic inflammation has been implicated in non-eosinophilic asthma (NEA) in adults, but little is known about NEA in children/adolescents. We assessed clinical and inflammatory characteristics of NEA in adolescent asthma.

Methods: Airway inflammation, sputum endotoxin, airway hyper-reactivity, atopy and lung function were assessed in 77 adolescents with asthma and 68 without asthma (12-17 years).

Relationship between airway neutrophilia and ageing in asthmatics and non-asthmatics.

Background And Objective: Increased sputum neutrophilia has been observed in asthma, but also during normal ageing in asthmatics and non-asthmatics. It remains unclear what constitutes 'normal' neutrophil levels in different age groups.

Methods: We assessed the relationship between age and airway neutrophils of 194 asthmatics and 243 non-asthmatics (age range: 6-80 years).

Identifying leukocyte populations in fresh and cryopreserved sputum using flow cytometry.

Background: Airway inflammation is commonly assessed by sputum induction followed by a differential cell count (DCC) using light microscopy. This method is prone to intercounter variability and poor reproducibility. We aimed to develop a more objective method using flow cytometry (FCM).

Importance of allergy in asthma: an epidemiologic perspective.

There has been a global epidemic of asthma during the past half-century. More recently, the prevalence has leveled off or declined in many Western countries, whereas the prevalence in less affluent nations is still increasing. The reasons for this and the different geographical patterns of asthma prevalence remain unclear.

Measurement of exhaled nitric oxide in a general population sample: a comparison of the Medisoft HypAir FE(NO) and Aerocrine NIOX analyzers.

Background And Objective: Measuring the fraction of nitric oxide in exhaled breath (FE(NO)) is increasingly utilized to assess airway inflammation in asthma. The primary aim of this study was to compare exhaled nitric oxide measurements obtained using two devices from different manufacturers, that is, the recently marketed portable and electrochemical-based Medisoft HypAir FE(NO) and the well-established chemiluminescence-based Aerocrine NIOX analyzer, in an unselected population.

Methods: FE(NO) measurements were conducted in 106 subjects (86 healthy; 20 asthmatic; 56.

Bromotyrosines in sputum proteins and treatment effects of terbutaline and budesonide in asthma.

Background: Inhaled corticosteroids are widely used in the treatment of persistent asthma, usually combined with inhaled beta2-agonists. Previous research suggests that short-acting beta2-agonists (SABAs) may downregulate the anti-inflammatory effects of inhaled corticosteroids, thereby increasing asthma morbidity.

Objective: To determine whether 3-bromotyrosine and 3,5-dibromotyrosine levels, specific markers of eosinophil activation, reflect treatment effects on airway inflammation of inhaled corticosteroids and SABAs and support previous conclusions.

Suitability of forced expiratory volume in 1 second/forced vital capacity vs percentage of predicted forced expiratory volume in 1 second for the classification of asthma severity in adolescents.

Objective: To determine whether lung function alters asthma severity based on symptom history in asthmatic adolescents.

Design: Data on asthma symptoms and lung function were collected from adolescents randomly selected from the general population.

Setting: Five schools from the central Wellington, New Zealand, area during 2003 to 2005.

Mechanism of nitrite oxidation by eosinophil peroxidase: implications for oxidant production and nitration by eosinophils.

Eosinophil peroxidase is a haem enzyme of eosinophils that is implicated in oxidative tissue injury in asthma. It uses hydrogen peroxide to oxidize thiocyanate and bromide to their respective hypohalous acids. Nitrite is also a substrate for eosinophil peroxidase.

Eosinophil peroxidase produces hypobromous acid in the airways of stable asthmatics.

Eosinophil peroxidase and myeloperoxidase use hydrogen peroxide to produce hypobromous acid and hypochlorous acid. These powerful oxidants may damage the lungs if they are produced as part of the inflammatory response in asthma. The aim of this study was to determine if peroxidases generate hypohalous acids in the airways of individuals with stable asthma, and if they affect lung function.