Correlation of nitrites in breath condensates and lung function in asthmatic children

Alpine altitude climate treatment for severe and uncontrolled asthma: An EAACI position paper

Currently available European Alpine Altitude Climate Treatment (AACT) programs combine the physical characteristics of altitude with the avoidance of environmental triggers in the alpine climate and a personalized multidisciplinary pulmonary rehabilitation approach. The reduced barometric pressure, oxygen pressure, and air density, the relatively low temperature and humidity, and the increased UV radiation at moderate altitude induce several physiological and immunological adaptation responses. The environmental characteristics of the alpine climate include reduced aeroallergens such as house dust mites (HDM), pollen, fungi, and less air pollution. These combined factors seem to have immunomodulatory effects controlling pathogenic inflammatory responses and favoring less neuro‐immune stress in patients with different asthma phenotypes. The extensive multidisciplinary treatment program may further contribute to the observed clinical improvement by AACT in asthma control and quality of life, fewer exacerbations and hospitalizations, reduced need for oral corticosteroids (OCS), improved lung function, decreased airway hyperresponsiveness (AHR), improved exercise tolerance, and improved sinonasal outcomes. Based on observational studies and expert opinion, AACT represents a valuable therapy for those patients irrespective of their asthma phenotype, who cannot achieve optimal control of their complex condition despite all the advances in medical science and treatment according to guidelines, and therefore run the risk of falling into a downward spiral of loss of physical and mental health. In the light of the observed rapid decrease in inflammation and immunomodulatory effects, AACT can be considered as a natural treatment that targets biological pathways.

The Effects of Climate Therapy on Cardiorespiratory Fitness and Exercise-Induced Bronchoconstriction in Children with Asthma

We investigated whether a 1-week stay in the mountains may have a positive impact on Exercise-Induced Bronchoconstriction (EIB) and cardiorespiratory endurance in asthmatic children from an urban area. Spirometry was performed before and 10 min after a 20 m shuttle run test (20mSRT) on the first and seventh day of a summer asthma camp in the Italian Alps at 900 m of altitude. Spirometry z-scores were derived from the Global Lung Initiative 2012 prediction equations, and percentiles of the 20mSRT performance were assigned according to De Miguel-Etayo’s and Tomkinson’s predictive equations. A FEV1 decrease ≥10% after the exercise was defined as EIB. Particulate matter pollution was monitored during the camp and in the urban area of provenience. Twenty-four subjects (age range 7–16 years) were included. Frequency of EIB decreased from 58% (14/24) at day-1 to 33% (8/24) at the end of the camp (p = 0.08). Most subjects with a 20mSRT in the lowest quartile at day 1 had EIB (9/11). The proportion of children with a 20mSRT <25° percentile decreased from 45% (11/24) at day-1 to 16% (4/24) at day-7 (p = 0.02). Conclusion: One-week climate therapy in the mountains improved both bronchial hyperreactivity and cardiorespiratory endurance in our cohort of asthmatic children.

Altitude healing effect in severe asthmatic children

BACKGROUND

The beneficial effect of a climatic treatment in children with asthma was established quite some time ago, but the mechanism of this beneficial effect has not been fully elucidated. We investigated the role of the cytokines of the TH2 pathway, reactive oxygen species (ROS) and reactive nitrogen species (RNS) over the course of a high-altitude climatic therapy.

METHODS

A group of 67 children originating from various French towns suffering from uncontrolled severe asthma was sent via their medical specialists, to the Briançon climatic area. They were monitored over the course of an entire school year. During this time, they returned home for 15 days during the Christmas holidays. At each stage, assessment of asthma control, lung function examination (peak flow meter and spirometry), and measurement of exhaled NO, ROS and RNS in exhaled breath condensate (EBC), and the level of cytokines in the plasma of the TH2 pathway were carried out.

RESULTS

The degree of asthma control improved at high altitude and worsened upon returning home. The average value of the peak expiratory flow also improved during the first 3 months but then worsened upon returning home, while the other spirometric parameters did not change. The level of expired NO and the scores for quality of life underwent a similar change. The level of RNS and ROS in the EBC did not change significantly. Besides, a marked and statistically significant decrease in the level of IL-13 and IL-10 was noted.

CONCLUSION

The beneficial effect of a climatic stay of children suffering from allergic asthma at altitude appears to be linked with less allergenic stimulation.

Lung function improvement and airways inflammation reduction in asthmatic children after a rehabilitation program at moderate altitude

BACKGROUND

Rehabilitational programs at moderate altitude (1500-2500 m) showed improvement of lung function and reduction in airways inflammation in asthmatic adults. Allergen avoidance was postulated as the major cause of these improvements.

METHODS

Spirometries of 344 and fractional exhaled nitric oxide measurements (FeNO) of 124 asthmatic children and adolescents, staying in a rehabilitation hospital in Davos (1590 m) with at least 14 days between admission and discharge, were analyzed in association with atopic sensitization (skin-prick testing and/or specific IgE), level of asthma control, and inhalative corticosteroid (ICS) dose.

RESULTS

Pulmonary conditions improved significantly on average during the sojourn. Uncontrolled asthmatics benefited most with an absolute increase in predicted FEV₁ , MEF₂₅ , and MEF₇₅ of 7.7%, 9.9%, and 12.7%, respectively (P < .001). FeNO decreased by 36.9 ppb for uncontrolled, by 26.9 ppb for partly controlled, and by 11.8 ppb for controlled asthmatics. In uncontrolled subjects, pulmonary improvement was comparable between patients with and without house dust mites (HDM) sensitization. Pulmonary improvements of pollen-sensitized patients were not dependent on the season of the sojourn. For the group with constant ICS level, the absolute increase in FEV₁ was 4.9% (P < .001) with a FeNO decreased by 32.7 ppb (P < .001). When the ICS dose was elevated by one GINA level, the absolute increase in FEV₁ was slightly higher (6.6%, P < .001), with a FeNO decrease of 31.4 ppb (P < .001).

CONCLUSION

Inpatient rehabilitation at moderate altitude improved pulmonary conditions in asthmatic children and adolescents independent of sensitization status to HDM or pollen. A positive effect was also observed in patients without change in medication.

High-altitude alpine therapy and lung function in asthma: systematic review and meta-analysis

We used meta-analysis to measure the effect of high-altitude climate therapy (HACT) on lung function outcomes in asthma, and systematically searched PubMed, Embase and www.elibrary.ru for publications appearing from 1970 to mid-2015. We included studies carried out with children or adults with an exposure of up to 12 weeks at an altitude of ≥1500 m above sea level. Changes in forced expiratory volume in 1 s (FEV₁), FEV₁/vital capacity ratio or peak expiratory flow rate as the HACT intervention outcomes were analysed. We included data for 907 participants (age range 4–58 years) from 21 studies, altogether including 28 substrata based on asthma type or severity. Only three of 21 included studies had high quality, whereas 93% of substudies reported lung function improvement with an overall pooled standardised mean difference (SMD) of 0.53 (95% CI 0.43–0.62). The measured effect of HACT was greater in adults (SMD 0.75, 95% CI 0.63–0.88, n=14) than in children (SMD 0.24, 95% CI 0.09–0.38, n=14). Studies at altitude >2000 m above sea level yielded the same effect as those at lower altitude. Based on a cut-point of a 0.50 change in SMD to define a meaningful clinical difference, HACT appears to have efficacy as an intervention. This extent of benefit appears to be limited to adults with asthma.

High-altitude alpine therapy may be an effective intervention to improve lung function in patients with asthmahttp://ow.ly/u3i23008vU5

The analysis of volatile organic compounds in exhaled breath and biomarkers in exhaled breath condensate in children - clinical tools or scientific toys?

Current monitoring strategies for respiratory diseases are mainly based on clinical features, lung function and imaging. As airway inflammation is the hallmark of many respiratory diseases in childhood, noninvasive methods to assess the presence and severity of airway inflammation might be helpful in both diagnosing and monitoring paediatric respiratory diseases. At present, the measurement of fractional exhaled nitric oxide is the only noninvasive method available to assess eosinophilic airway inflammation in clinical practice. We aimed to evaluate whether the analysis of volatile organic compounds (VOCs) in exhaled breath (EB) and biomarkers in exhaled breath condensate (EBC) is helpful in diagnosing and monitoring respiratory diseases in children. An extensive literature search was conducted in Medline, Embase and PubMed on the analysis and applications of VOCs in EB and EBC in children. We retrieved 1165 papers, of which nine contained original data on VOCs in EB and 84 on biomarkers in EBC. These were included in this review. We give an overview of the clinical applications in childhood and summarize the methodological issues. Several VOCs in EB and biomarkers in EBC have the potential to distinguish patients from healthy controls and to monitor treatment responses. Lack of standardization of collection methods and analysis techniques hampers the introduction in clinical practice. The measurement of metabolomic profiles may have important advantages over detecting single markers. There is a lack of longitudinal studies and external validation to reveal whether EB and EBC analysis have added value in the diagnostic process and follow-up of children with respiratory diseases. In conclusion, the use of VOCs in EB and biomarkers in EBC as markers of inflammatory airway diseases in children is still a research tool and not validated for clinical use.

Correlation between nitrites in induced sputum and asthma symptoms in asthmatic schoolchildren

OBJECTIVE

To determine if nitrites (nitric oxide metabolites) measured in induced sputum decrease and correlate with improvement of clinical asthma symptoms after treatment, we performed a prospective longitudinal study in a tertiary care hospital in Arequipa, Peru.

METHODS

In 95 schoolchildren with mild and moderate persistent asthma we determined nitrites in induced sputum samples (measured using the Griess assay). Clinical parameters and exercise bronchial challenge (EBC) test were performed twice, at baseline and after 3 months of beclomethasone-dipropionate treatment (median doses: 300 mcg/day, IQR: 300-450).

RESULTS

Sixty out of 95 children completed the study (median age of 9-year [IQR: 7-13]). A significant change in sputum nitrites levels between admission and the end of the study was observed (34.4 nmol/ml [IQR:18.2-58.4] and 11.2 nmol/ml [6-20.1], respectively, P = < 0.0001). Also a significant correlation between decrease of sputum nitrites levels and improvement of clinical parameters (acute exacerbations [r = 0.361, P = 0.005]; use of salbutamol [r = 0.322, P = 0.013]; emergency visits [r = 0.275, P = 0.033]; and school absence [r = 0.41, P = 0.001]) from admission to the end of the study was found. However, sputum nitrites levels did not correlated with peripherical blood eosinophils or serum IgE levels or with EBC test at any point of the study. The decrease of sputum nitrites levels after the treatment was significant in each asthma group (mild and moderate), but not between groups.

CONCLUSION

This study showed that measured nitrite in induced sputum (a simple and cheap non-invasive method) is a good alternative for monitoring asthmatic treatment in schoolchildren.

Does climate therapy at moderate altitudes improve pulmonary function in asthma patients? A systematic review

PURPOSE

Allergic bronchial asthma is one of the most common chronic diseases worldwide. For many years, the climate at moderate altitude has been used as an alternative therapy for patients suffering from bronchial asthma. The aim of such therapy is to reduce the medication dose and to improve the quality of life for each patient. The aim of our current work was to assess published data evaluating the effects of climate therapy at moderate altitude on the health status of patients with bronchial asthma. The health status is represented through surrogate parameters for the pulmonary function (forced expiratory volume in one second (FEV1)), bronchial hyperresponsiveness (PC20), and inflammation (total number of eosinophils, eosinophilic cationic protein, and exhaled nitric oxide).

METHODS

Our systematic review included randomized controlled trials (RCTs) and single-armed studies with adults and children participating. Included in our review were climate therapies occurring at moderate altitudes between 1,500 and 2,500 m and evaluation of patient FEV1 or PC20 values.

RESULTS

A literature research in MEDLINE and EMBASE identified three RCTs, two clinically controlled trials, and 15 single-armed studies. Analysis revealed a lack of evidence regarding the moderate altitude therapy arising from small sample sizes, deficits in documentation, and heterogeneous results. Most of the studies, however, showed a tendency for improvement of the analyzed parameters.

CONCLUSIONS

The currently available data do not allow for valid and generalizable recommendations with respect to moderate altitude therapy for patients with allergic bronchial asthma. There is a need for additional, qualitatively strong research including larger sample sizes and randomized, controlled trial design.

Inpatient paediatric rehabilitation in chronic respiratory disorders

Inpatient pulmonary rehabilitation programs have evolved from tuberculosis sanatoriums to modern medical centres providing standardized comprehensive care in a multidiciplinatory environment. Goals of rehabilitation programs for children and adolescents include restoration of professional activity, improvement of health condition, compliance and disease management as well as restoration of quality of life. Eligibility for an intervention is assessed by defined social and medical criteria. Comprehensive pulmonary rehabilitation programs provide a wide range of health care recourses, including diagnostic procedures, specific medical care, educational interventions and a multiprofessional team. Paediatric rehabilitation programs for chronic respiratory diseases, such as asthma or cystic fibrosis, have been shown to reduce symptoms, increase aerobic fitness and physical strength, improve pulmonary function and inflammation and enhance compliance, self-management, quality of life and psychological symptoms. Regional climatic effects have demonstrated an additional positive effect on the rehabilitation outcome. In addition, first evidence suggests an overall reduction of health care costs.

Increased exhaled nitrite in children with allergic asthma is not related to nitric oxide formation

INTRODUCTION

Nitrite sampled from the upper airways could originate from inflammation-induced nitric oxide (NO), as reports of elevated nitrite in exhaled breath condensate (EBC) from asthmatics suggest, but also through bacterial action in the pharyngo-oral tract.

OBJECTIVES

To correlate EBC nitrite and nitrate to exhaled NO (FENO, fraction of expired NO) and other markers of disease activity in children with allergic asthma and thereby further investigate their role and origin.

MATERIALS AND METHODS

EBC was collected from 27 asthmatic subjects (ages 6-17 years, all immunoglobulin E-positive for aeroallergens) and 21 age-matched non-atopic healthy controls for fluorometric analysis of nitrite and nitrate. These markers were compared with measurements of FENO, blood eosinophil count (EOS), methacholine reactivity (PD(20)) and baseline spirometry.

RESULTS

EBC nitrite, in contrast to nitrate, was significantly increased (P < 0.01) in the asthmatic children. They also had increased levels of FENO (P < 0.001) and EOS (P < 0.001) along with decreased PD(20) (P < 0.001) and FEV1/FVC (P < 0.01). However, there was no correlation between EBC nitrite and FENO (r = 0.05) or any other marker of disease activity in the asthmatic children, whereas between the other markers correlations could be established.

CONCLUSION

EBC nitrite is elevated in childhood asthma but the lack of correlation to FENO and other markers, together with simultaneously normal levels of nitrate, make its origin as a metabolite of inflammation-induced NO questionable.

Nitrites in induced sputum as a simple and cheap non-invasive marker of airway inflammation for asthmatic schoolchildren

To determine if there are differences in the nitric oxide metabolites (nitrites) in sputum of patients with persistent asthma and healthy schoolchildren, we performed a case-control study in a tertiary care hospital in Arequipa, Perú. Nitrites in induced sputum samples were measured using the Griess assay in 30 persistent asthmatics (mean age of 10.1 yr) and 30 controls (mean age of 11.9 yr). The mean +/- s.d. of nitrites among asthmatics was significantly higher than the controls (16.30 +/- 8.6 vs. 10.25 +/- 4.68 nmol/ml, respectively, p = 0.001). Moreover, the nitrite level in the sputum in children with severe persistent asthma was higher than in the level found in the moderate and mild asthmatics (32.83 +/- 9.48 vs. 18.10 +/- 1.96 vs. 11.84 +/- 4.73 nmol/ml, respectively, p < 0.01 for linear trend). This study showed for the first time in children that asthmatics have significantly higher levels of nitrites in induced sputum than healthy controls and that the level of nitrite correlates with the severity of the asthma. Nitrite levels in sputum, a simple and cheap, non-invasive method, may be a good alternative to measure the severity of inflammation in asthmatic children.

Exhaled breath condensate nitrite/nitrate and pH in relation to pediatric asthma control and exhaled nitric oxide

BACKGROUND

Combining exhaled breath condensate (EBC) and exhaled nitric oxide (eNO) may be a useful, non-invasive method to assess airway inflammation in pediatric asthma. This cross-sectional study evaluated the relationship of both EBC nitrite/nitrate (NOx) and EBC pH with asthma control and eNO in asthmatic, normal, and atopic children.

METHODS

A total of 92 children were recruited, comprising 62 with asthma, 14 with atopy only, and 16 who were normal and non-atopic. All completed a questionnaire for asthma symptoms and control. Variables measured were spirometry, EBC NOx, pH, and eNO.

RESULTS

EBC NOx in those with asthma (mean 8.4 microM, CI 7.5-9.4) was significantly elevated when compared with normal (4.8 microM, CI 3.4-6.2, P = 0.0007) and atopic children (6.5 microM, CI 4.0-9.1, P = 0.02). The mean level of eNO was significantly higher in those with asthma (43.7 ppb, CI 34.7-51.1, P < 0.001) and atopy (24 ppb, CI 16.7-31.2, P < 0.05) when compared with normal children (11.5 ppb, CI 6.7-16.2). There was a significantly lower pH in those with asthma and a FEV(1) < 80% predicted (P = 0.03), but no significant overall differences in EBC pH between the three groups of children. There was a significant correlation between eNO and EBC NOx in the group as a whole, but not between eNO and EBC pH.

CONCLUSIONS

Mean EBC NOx levels differ between children with asthma, atopy, and those who are normal, but it is not interchangeable with eNO. EBC pH may be an additional marker of asthma control.

Inflammatory Mediators in Exhaled Breath Condensate of Children With Obstructive Sleep Apnea Syndrome

BACKGROUND

Upper airway inflammation is now recognized in adults with obstructive sleep apnea (OSA) syndrome. However, the role played by eicosanoids such as leukotrienes and prostaglandins is unclear.

OBJECTIVE

To investigate whether eicosanoids are measurable in exhaled breath condensate (EBC), and to determine whether differences in these inflammatory mediators emerge among children with and without sleep-disordered breathing (SDB).

METHODS

EBC was collected from 50 consecutive snoring children undergoing overnight polysomnography for suspected SDB, and from 12 nonsnoring control subjects. Prostaglandin E2 (PGE2), leukotriene B4 (LTB4), and cysteinyl leukotrienes (cys-LTs: leukotriene C4 [LTC4]/leukotriene D4 [LTD4]/leukotriene E4 [LTE4]) EBC levels were analyzed using enzyme-linked immunosorbent assay.

RESULTS

LTB4 levels were elevated in children with an apnea-hypopnea index (AHI) > 5/h (SDB; 97.6 +/- 6.3 pg/mL) compared to children with an AHI < 5/h (mild SDB; 66.4 +/- 19.1 pg/mL; p < 0.01) and control subjects (27.8 +/- 3.7 pg/mL; p < 0.01). Similarly, cys-LT (LTC4/LTD4/LTE4) concentrations were also increased in SDB (45.1 +/- 10.6 pg/mL in SDB vs 27.6 +/- 8.3 pg/mL in mild SDB, and 15.7 +/- 7.6 pg/mL in control subjects; p < 0.01). In contrast, PGE2 concentrations were similar among the three groups.

CONCLUSIONS

Inflammatory mediators such as leukotrienes and prostaglandins can be readily quantified in EBC collected from the upper airway of children. Disease severity-dependent increases in leukotriene concentrations (LTB4 and LTC4/LTD4/LTE4) emerge among children and may serve as a noninvasive tool in the clinical assessment of these children.

Variability of nitric oxide metabolites in exhaled breath condensate

The collection of exhaled breath condensate (EBC) is simple and non-invasive, however, there are few data on the methodological aspects affecting concentrations of compounds in EBC. The aim of this study was to investigate methodological issues for measuring nitric oxide metabolites (NO(x)) in EBC. Twenty-five healthy adults (12 females, age range 23-55 years) and 22 children (11 females, age range 7-6 years) were recruited for studies investigating inter- and intra-day repeatability, repeatability with controlled expiratory flows and temperature, flow dependence, and analytical variability of EBC NO(x). Both intra- and inter-day repeatability was poor with a coefficient of repeatability of 103.4% of the mean difference between intra-day (15 min) measures and 118.6% of inter-day (24 h) differences. Repeatability was not improved when expiratory flow and temperature of the collection device were controlled. However, some of the variability (approximately 50%) may be accounted for by variability in the analytical technique (analytical variability) and this may result from difficulties in controlling for contamination. NO(x) levels were not affected by different expiratory flows in either adults or children but there was still significant variation within individuals. Levels of NO(x) in EBC seem to be highly variable and this needs to be considered if EBC NO(x) is to be used in clinical studies.

High-Altitude Climate Therapy Reduces Local Airway Inflammation and Modulates Lymphocyte Activation

High-altitude climate therapy is a well-established therapeutic option, which improves clinical symptoms in asthma. However, little is known about the underlying immunological mechanisms. The study investigates the influence of high-altitude climate therapy on airway inflammation and cellular components of specific and unspecific immune response. Exhaled NO significantly decreased within 3 weeks of therapy in patients with allergic and intrinsic, moderate and severe asthma. Interleukin-10 (IL-10)-secreting peripheral blood mononuclear cells (PBMC) increased within 3 weeks of therapy in six of 11 patients, whereas transforming growth factor-beta(1)-secreting PBMC remained stable. Furthermore, monocyte activation, assessed by CD80 expression significantly decreased during therapy. The frequency of CRTH2-expressing T cells decreased, while regulatory T cells (T(reg)) remained stable. FOXP3 and GATA-3 mRNA expression in CD4(+) T cells did not change, while interferon-gamma and IL-13 mRNA expression decreased in eight of 10 patients. The current data demonstrate that high-altitude climate therapy reduces local airway inflammation. Furthermore, monocytes switch towards a tolerogenic phenotype under high-altitude climate therapy. The T(reg)/Th2 ratio increases; however, because of the absence of antigens/allergens, no de novo differentiation of Th2 nor T(reg) cells is observed. The high-altitude climate therapy therefore may form the immunological basis for the endogenous control of allergen-driven diseases.