Association between individual sensor behavior of an electronic nose and airways inflammation in children with asthma: a pilot study at alpine altitude climate.

BACKGROUND: Markers of airway inflammation can be helpful in the management of childhood asthma. Residential activities, such as intensive asthma camps at alpine altitude climate (AAC), can help reduce bronchial inflammation in patients who fail to achieve optimal control of the disease. Analysis of volatile organic compounds (VOCs) can be obtained using electronic devices such as e-Noses. We aimed to identify alterations in urinary e-Nose sensors among children with asthma participating in an intensive camp at AAC and to investigate associations between urinary e-Nose analysis and airway inflammation. METHODS: We analyzed data collected in children with asthma recruited between July and September 2020. All children were born and resided at altitudes below 600 m asl. Urinary VOCs (measured using the Cyranose 320® VOC analyzer), Fractional exhaled Nitric Oxide (FeNO) and spirometry were evaluated upon children's arrival at the Istituto Pio XII, Misurina (BL), Italy, at 1756 m asl (T0), and after 7 (T1) and 15 days (T2) of stay. RESULTS: Twenty-two patients (68.2% males; median age: 14.5 years) were enrolled. From T0 to T1 and T2, the negative trend for FeNO was significant (p < .001). Significant associations were observed between e-Nose sensors S7 (p = .002), S12 (p = .013), S16 (p = .027), S17 (p = .017), S22 (p = .029), S29 (p = .021), S31 (p = .009) and ΔFeNO at T0-T1. ΔFeNO at T0-T2 was significantly associated with S17 (p = .015), S19 (p = .004), S21 (p = .020), S24 (p = .012), S25 (p = .018), S26 (p = .008), S27 (p = .002), S29 (p = .007), S30 (p = .013). CONCLUSIONS: We showed that a decrease in FeNO levels after a short sojourn at AAC is associated with behaviors of individual urinary e-Nose sensors in children with asthma.

A positive effect of a short period stay in Alpine environment on lung function in asthmatic children.

Lung function is a central issue in diagnosis and determination of asthma severity and asthma control has been previously reported to improve after a stay in mountain environment for at least 2 weeks. No data are available for shorter periods of stay, in particular for small airways during a stay at altitude. The aim of this study is to focus on changes in respiratory function, regarding both the central airways and the peripheral airways in the first 2 weeks of stay in a mountain environment in asthmatic children. In this study, 66 asthmatic children (age: 14 ± 2.8 years) were evaluated through spirometric and oscillometric tests at the time of arrival at the Istituto Pio XII, Misurina (BL), Italy, 1756 m above sea level (T0), after 24 h (T1), and 168 h (T2) of stay. FEV1%, FEF25%-75%, and FEV1/FVC increased significantly from T0 value both at T1 and T2 (respectively, p = 0.0002, p < 0.0001, p = 0.0002). Oscillometry showed a significant improvement in R5, R20, and R5-20 at both T1 and T2 as compared to T0 (respectively, p = 0.0001, p = 0.0002, and p = 0.049). Reactance at 5 Hz (X5) improved significantly at T2 versus T0, p = 0.0022. The area under reactance curve between Fres and 5 Hz (AX) was significantly reduced (p = 0.0001) both at T1 and T2 as compared to T0. This study shows an improvement in respiratory indices as soon as after 24 h of stay at altitude, persisting in the following week.

Severe asthma features in children: a case-control online survey.

BACKGROUND: Very few studies have explored the distinguishing features of severe asthma in childhood in Europe, and only one study was conducted in Southern Europe. The aim of this study was to provide a detailed characterization of children with severe asthma treated in specialized pediatric asthma centers across Italy. METHODS: We conducted a web-based data collection of family, environmental, clinical and laboratory characteristics of 41 patients aged 6-17 years with severe asthma, defined according to the recent guidelines of the European Respiratory Society and the American Thoracic Society, and 78 age-matched peers with non-severe persistent asthma. The patients have been enrolled from 16 hospital-based pediatric pulmonology and allergy centers in Northern, Central, and Southern Italy. Logistic regression analysis assessed the relationship between patients' characteristics and severe asthma or non-severe persistent asthma. RESULTS: Features independently and significantly associated with severe asthma included lifetime sensitization to food allergens [Odds ratio (OR), 4.73; 95 % Confidence Interval (CI), 1.21-18.53; p = 0.03], lifetime hospitalization for asthma (OR, 3.71; 95 % CI, 1.11-12.33; p = 0.03), emergency-department visits for asthma during the past year (OR = 11.98; 95 % CI, 2.70-53.11; p = 0.001), and symptoms triggered by physical activity (OR = 12.78; 95 % CI, 2.66-61.40; p = 0.001). Quality-of-life score was worse in patients with severe asthma than in subjects with non-severe persistent asthma (5.9 versus 6.6, p = 0.005). Self-perception of wellbeing was compromised in more than 40 % of patients in both groups. Children with severe asthma had lower spirometric z scores than non-severe asthmatic peers (all p < 0.001), although 56 % of them had a normal forced expiratory volume in 1 s. No differences were found between the two groups for parental education, home environment, patients' comorbidities, adherence to therapy, exhaled nitric oxide values, and serum eosinophils and IgE . CONCLUSIONS: As expected, children with severe asthma had more severe clinical course and worse lung function than peers with non-severe persistent asthma. Unlike previous reports, we found greater sensitization to food allergens and similar environmental and personal characteristics in patients with severe asthma compared to those with non-severe persistent asthma. Psychological aspects are compromised in a large number of cases and deserve further investigation.

Improved bronchodilator effect of deep inhalation after allergen avoidance in asthmatic children.

BACKGROUND: In healthy adults and children, deep inhalation (DI) is able to reverse induced bronchoconstriction. This ability is impaired in asthma, but the reasons are still to be elucidated. OBJECTIVES: This study investigated whether the bronchodilator effect of DI during methacholine-induced bronchoconstriction can be improved by allergen avoidance in asthmatic children, and its relationship with airway inflammation. METHODS: The effect of DI on methacholine-induced bronchoconstriction was studied at the beginning and the end of a 3-month allergen avoidance period at high altitude in 14 allergic asthmatic children who had severe asthma attacks. Changes in airway caliber were inferred from the respiratory resistance (Rrs) measured by a forced oscillation technique. Results were related to the percentage of eosinophils in induced sputum and compared with those obtained in 9 age-matched nonasthmatic children. RESULTS: In asthmatic subjects, DI had no significant effect on methacholine-induced increase in Rrs before (P=.62) but significantly reversed it after (P <.01) allergen avoidance. However, the ability of DI to reverse a methacholine-induced increase in Rrs tended to remain less in asthmatic than nonasthmatic children even after allergen avoidance (P=.05). In the asthmatic children, the percentage of eosinophils in induced sputum was decreased at the end of the allergen avoidance period (P <.001), without any significant correlation between sputum eosinophils and airway responsiveness to methacholine or effect of DI. CONCLUSION: A short period of allergen avoidance may improve the ability of DI to reverse induced bronchoconstriction in some asthmatic children. This effect is associated, yet not correlated, with a reduction in airway inflammation.

Time efficacy of a single dose of montelukast on exercise-induced asthma in children.

The aim of this study was to evaluate the timing of onset and the duration of action of a single oral-dose treatment with montelukast in comparison to placebo on exercise-induced asthma (EIA) in asthmatic children. Nineteen children (7-13 years) with stable asthma were evaluated. Patients undertook three consecutive treadmill exercise tests, respectively, 2, 12 and 24 h after a single-dose administration. A double-blind randomized, single-dose, placebo-controlled, crossover design was used. To assess bronchoconstriction after the exercise challenge, the maximal percentage fall in FEV1 (DeltaFEV1) from the baseline value was considered. Two hours after dosing, DeltaFEV1 was -15.33 +/- 2.93 for placebo and -13.33 +/- 2.03 for montelukast. At 12 h, DeltaFEV1 was -18.69 +/- 2.83 for placebo, -9.78 +/- 1.85 for montelukast (p < 0.005). No difference was observed between placebo (DeltaFEV1-10.21 +/- 2.07) and montelukast (DeltaFEV1-9.10 +/- 2.02) at 24 h. Analysis of the degree of protection showed a significant efficacy of montelukast (p = 0.02) in comparison with placebo only at 12 h. Montelukast showed a significant protective effect 12 h after dosing, but no effect after 2 and 24 h. In mild asthmatics, the timing of administration of single dosage before exercise should be strictly considered in order to obtain the drug protective effects.