Introduction of a new paediatric asthma guideline: Effects on asthma control levels.

BACKGROUND: In 2008, a new national paediatric asthma management guideline based on the international Global Initiative for Asthma (GINA) guideline was launched in the Netherlands. We studied whether asthma control and treatment regimens improved after introduction of the guideline by comparing survey data before and after the guideline introduction. METHODS: Two comparable groups of children (6-16 years) with asthma were included before (2004) and after (2013) the introduction of the guideline. Children, parents and paediatricians completed questionnaires about asthma symptoms, medication and healthcare use. Spirometry was performed. RESULTS: Data of 209 patients were analysed. Level of asthma control did not improve between 2004 and 2013 with a proportion of (partly) controlled asthmatics of 51% in 2004 and 59% in 2013 (p = 0.28). In 2013, paediatricians characterized 76% of children as (partly) controlled, while 59% of children was (partly) controlled according to GINA criteria (p < 0.05). Step-down treatment in controlled patients was more applied by paediatricians in 2013 compared to 2004 (from 8 to 40%, p < 0.05). Step-up treatment in uncontrolled patients did not improve. CONCLUSIONS: Asthma control did not improve after the introduction of the new guideline. Compared to 2004, an improvement was observed in step-down treatment in patients with controlled disease.

Association between exhaled inflammatory markers and asthma control in children.

The relationship between exhaled inflammatory markers and asthma control in children is unclear. To explore the association between inflammatory markers in exhaled breath (fractional nitric oxide (FeNO), volatile organic compounds (VOCs), cytokines/chemokines) and asthma control. To assess whether exhaled inflammatory markers are able to discriminate between children with persistently controlled/uncontrolled asthma. 96 asthmatic children were followed-up in a one-year observational study. Every 2 months, the following parameters were assessed: asthma control, FeNO, lung function (forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), exhaled VOCs, and cytokines/chemokines in exhaled breath condensate (EBC). Random Forest was used to analyse the relationship between exhaled inflammatory markers and asthma control. For each model, patients were randomly selected for a training set and validation set. To assess the accuracy of the classification models, receiver operating characteristic-curves (ROC-curves) were generated. No significant association was found between the exhaled inflammatory markers (FeNO, markers in EBC, VOCs) and asthma control (area under the ROC-curve 49%). However, 15 exhaled VOCs could discriminate between subgroups of children with persistently controlled and uncontrolled asthma during all clinical visits (area under the ROC-curve 86%). Adding FeNO and markers in EBC to this model, did not lead to a more accurate classification (area under the ROC-curve 87%). There was no association between exhaled inflammatory markers and asthma control in children. However, children with persistently controlled or uncontrolled asthma during the 12 month study period could be discriminated by a set of VOCs.

Biomarkers to predict asthma in wheezing preschool children.

Wheezing in preschool children is a very common symptom. An adequate prediction of asthma in these children is difficult and cannot be reliably assessed with conventional clinical tools. The study of potential predictive biomarkers in various media, ranging from invasive sampling (e.g. bronchoscopy) to non-invasive sampling (lung function testing and exhaled breath analysis), was comprehensively reviewed. The evolution in biomarker discovery has resulted in an 'omics' approach, in which hundreds of biomarkers in the field of genomics, proteomics, metabolomics, and 'breath-omics' can be simultaneously studied. First, results on gene expression and exhaled breath profiles in predicting an early asthma diagnosis are promising. However, many hurdles need to be overcome before clinical implementation is possible. To reliably predict asthma in a wheezing child, probably a holistic approach is needed, combining clinical information with blood sampling, lung function tests, and potentially exhaled breath analysis. The further development of predictive, non-invasive biomarkers may eventually improve an early asthma diagnosis in wheezing preschool children and assist clinicians in early treatment decision-making.

Prediction of asthma exacerbations in children: results of a one-year prospective study.

BACKGROUND: Underdiagnosis and low levels of asthma control are frequent occurring problems in patients with asthma. OBJECTIVE: The study aim was to evaluate the ability of non-invasive inflammatory markers in exhaled breath to predict exacerbations of childhood asthma, and to assess the time course of changes in these exhaled markers before, during and after exacerbations. METHODS: The design was a prospective one-year longitudinal study. Regular two-month visits at the outpatient clinic were performed. Forty children with asthma (aged 6-16 years) participated. The primary outcome measure was the occurrence of an exacerbation. Assessment was made of the presence and severity of pulmonary symptoms, use of medication, and measurements of forced expiratory volume in 1 s using home monitor. The following independent parameters were assessed during outpatient visits: (1) exhaled nitric oxide, (2) inflammatory markers in exhaled breath condensate: acidity, nitrite, hydrogen peroxide, interleukin-1α, -5, -13, interferon-γ, (3) lung function, (4) asthma control score. RESULTS: Thirty-eight of 40 children completed the study. Sixteen children developed exacerbations, of which ten were moderate and six severe. Univariate Cox regression analysis revealed that condensate acidity, interleukin-5 and asthma control score were significant predictors of an asthma exacerbation (P < 0.05). In the multivariate Cox regression analysis, exacerbations were best predicted by the asthma control score and by the level of interleukin-5 in exhaled breath condensate (Wald scores of 7.19 and 4.44, P = 0.007 and P = 0.035 respectively). The predicted survival curve of this multivariate model showed a two times reduced risk on exacerbations in the category of children with the 10% most optimal values of IL-5 and asthma control score. CONCLUSIONS AND CLINICAL RELEVANCE: Both exhaled breath condensate interleukin-5 level and asthma control score were significant predictors of asthma exacerbations. These findings open up the possibility of assessing the potential of such parameters to titrate asthma treatment in future studies.

Symptoms, but not a biomarker response to inhaled corticosteroids, predict asthma in preschool children with recurrent wheeze.

BACKGROUND: A reliable asthma diagnosis is challenging in preschool wheezing children. As inhaled corticosteroids (ICS) are more effective in asthmatics than in children with transient wheeze, an ICS response might be helpful in early asthma diagnosis. METHODS: 175 children (aged two-four years) with recurrent wheeze received 200 µg Beclomethasone extra-fine daily for eight weeks. Changes in Exhaled Breath Condensate (EBC) biomarkers (pH, interleukin (IL)-1α, IL-2, IL-4, IL-5, IL-10, IFN-γ, sICAM, and CCL-11), Fractional exhaled Nitric Oxide (FeNO), airway resistance, and symptoms were assessed. At six years of age a child was diagnosed as transient wheezer or asthmatic. Adjusted logistic regression analysis was performed with multiple testing correction. RESULTS: 106 transient wheezers and 64 asthmatics were analysed at six years of age. Neither changes in EBC biomarkers, nor FeNO, airway resistance, or symptoms during ICS trial at preschool age were related to asthma diagnosis at six years of age. However, asthmatics had more airway symptoms before the start of the ICS trial than transient wheezers (P < 0.01). DISCUSSION: Although symptom score in preschool wheezing children at baseline was associated with asthma at six years of age, EBC biomarkers, airway resistance, or symptom response to ICS at preschool age could not predict asthma diagnosis at six years of age.

Can exhaled inflammatory markers predict a steroid response in wheezing preschool children?

BACKGROUND: The efficacy of inhaled corticosteroids (ICS) varies among wheezing preschool children. Currently, it is not possible to predict which fraction of wheezing children will benefit from an ICS treatment. OBJECTIVE: We explored whether fractional exhaled nitric oxide (FeNO) and inflammatory markers in exhaled breath condensate (EBC) can predict an ICS response in preschool wheezers. METHODS: An 8-week ICS study (registered at Clinicaltrial.gov: NCT 00422747; 200 µg; beclomethasone extra-fine daily) was performed in 93 wheezing children (age range 2.0-4.4 years). At baseline, FeNO was determined off-line. EBC was collected using a closed glass-condenser. The acidity of EBC was determined and other EBC markers [interleukin (IL)-1α, IL-2, IL-4, IL-5, IL-10, soluble intercellular adhesion molecule, interferon-γ, eotaxin] were measured using a multiplex immunoassay. The change in airway resistance (Rint) and symptom score following ICS treatment was related to atopy (positive Phadiatop Infant test), FeNO and EBC markers. RESULTS: Airway resistance and symptoms mildly improved after ICS treatment [median (IQR): 1.4 (1.2-1.7) to 1.3 (1.1-1.5) kPa s/L, symptom score: 26 (23-28) to 28 (24-29), P < 0.01, respectively]. Only IL-10 and atopy had limited predictive value regarding a change in symptoms [ß (SE) =-0.13 (0.07), P = 0.08, ß (SE) = 2.05 (1.17), P = 0.08, respectively]. CONCLUSIONS AND CLINICAL RELEVANCE: We did not find convincing evidence that FeNO and EBC markers could predict an ICS response in preschool wheezers. Recommendations for future studies on this topic are given.

Increased cytokines, chemokines and soluble adhesion molecules in exhaled breath condensate of asthmatic children.

BACKGROUND: Airway inflammation in asthma is characterized by the production of cytokines, chemokines and soluble adhesion molecules. The assessment of these inflammatory biomarkers in exhaled breath condensate (EBC) is hampered by low detection rates. However, the use of a glass condenser system combined with a sensitive analytical technique may increase the possibility to assess these biomarkers in EBC in a reliable way. OBJECTIVE: (1) To assess the detection rates of cytokines (IL-1alpha, -1beta, -2, -4, -5, -6, -10, -12p70, -13, -18, IFN-gamma, TNF-alpha), chemokines [MIP1alpha (CCL3), MIF, eotaxin (CCL11), RANTES (CCL5), IP10 (CXCL10), IL8 (CXCL8), MCP1] and soluble adhesion molecules [soluble intercellular adhesion molecule (sICAM), soluble vascular adhesion molecule (sVCAM)] in EBC of children with asthma and healthy control children; (2) To study the differences in the biomarker concentration between children with asthma and controls. METHODS: Sixty children were included: 31 asthmatics (71% atopic) and 29 controls. Exhaled breath condensate was collected using a glass condenser system. The inflammatory markers (IM) were analysed using multiplex immunoassay technology. RESULTS: Detection percentages of cytokines, chemokines and adhesion molecules ranged from 94% to 100%, except for eotaxin (CCL11) and RANTES (CCL5) (detection rates of 10% and 45% in healthy controls, respectively). The intra-subject variability of biomarkers in EBC in the group as a whole ranged from 5.2% to 35.0%. In asthmatics, the levels of cytokines (IL-2, -4, -5, -6, -13, IFN-gamma), chemokines (MIP1alpha [CCL3], MIF, RANTES [CCL5], IP10 [CXCL10], IL8 [CXCL8], MCP1) and adhesion molecules (sICAM, sVCAM) were significantly increased in comparison with controls (P<0.05). CONCLUSION: If collected with a glass condenser and analysed by multiplex immunoassay technology, cytokines, chemokines and soluble adhesion molecules can be reliably demonstrated in EBC of children. Most of these IM were elevated in EBC of asthmatics compared with controls.

Volatile organic compounds in exhaled breath as a diagnostic tool for asthma in children.

BACKGROUND: The correct diagnosis of asthma in young children is often hard to achieve, resulting in undertreatment of asthmatic children and overtreatment in transient wheezers. OBJECTIVES: To develop a new diagnostic tool that better discriminates between asthma and transient wheezing and that leads to a more accurate diagnosis and hence less undertreatment and overtreatment. A first stage in the development of such a tool is the ability to discriminate between asthmatic children and healthy controls. The integrative analysis of large numbers of volatile organic compounds (VOC) in exhaled breath has the potential to discriminate between various inflammatory conditions of the respiratory tract. METHODS: Breath samples were obtained and analysed for VOC by gas chromatography-mass spectrometry from asthmatic children (n=63) and healthy controls (n=57). A total of 945 determined compounds were subjected to discriminant analysis to find those that could discriminate diseased from healthy children. A set of samples from both asthmatic and healthy children was selected to construct a model that was subsequently used to predict the asthma or the healthy status of a test group. In this way, the predictive value of the model could be tested. MEASUREMENTS AND MAIN RESULTS: The discriminant analyses demonstrated that asthma and healthy groups are distinct from one another. A total of eight components discriminated between asthmatic and healthy children with a 92% correct classification, achieving a sensitivity of 89% and a specificity of 95%. Conclusion The results show that a limited number of VOC in exhaled air can well be used to distinguish children with asthma from healthy children.

Biomarker reproducibility in exhaled breath condensate collected with different condensers.

Optimal collection and analysis of exhaled breath condensate (EBC) are prerequisites for standardisation and reproducibility of assessments. The present study aimed to assess reproducibility of EBC volume, hydrogen peroxide (H(2)O(2)), 8-isoprostane and cytokine measurements using different condensers, including a newly developed glass condenser. At four points in time, 30 healthy subjects performed sequential EBC collections randomly using the following four condensers: glass, silicone, EcoScreen (Erich Jaeger GmbH, Hoechberg, Germany) and an optimised glass condenser. In small EBC samples, H(2)O(2) was measured by spectrophotometer, 8-isoprostane by enzyme immunoassay, and cytokines by multiplexed xMAP technology (Luminex Corporation, Austin, TX, USA). The optimised glass condenser yielded significantly more EBC volume (median 2,025 microL, interquartile range 1,600-2,525). The reproducibility of EBC volume, yielded by the new glass condenser, was comparable with EcoScreen (19-20 coefficients of variation (CV)%), but was significantly better compared with silicone and glass (29-37 CV%). The new condenser was associated with significantly more detections of H(2)O(2), 8-isoprostane, interleukin-2, -4, -5 and -13, and tumour necrosis factor-alpha. Isoprostane concentrations were significantly higher using the new condenser, whereas H(2)O(2) and cytokine concentrations were not. Reproducibility of biomarkers was equally variable for all condenser types. In conclusion, significantly more exhaled breath condensate volume and biomarker detections were found using the optimised glass condenser, including higher 8-isoprostane levels. However, biomarker reproducibility in exhaled breath condensate in healthy adults was not influenced by the type of condenser.

Exhaled nitric oxide and biomarkers in exhaled breath condensate indicate the presence, severity and control of childhood asthma.

BACKGROUND: Exhaled nitric oxide and inflammatory biomarkers in exhaled breath condensate may be useful to diagnose and monitor childhood asthma. Their ability to indicate an asthma diagnosis, and to assess asthma severity and control, is largely unknown. OBJECTIVE: To study (1) the ability of exhaled nitric oxide and inflammatory markers in exhaled breath condensate (nitrite, nitrate, hydrogen peroxide, 8-isoprostane, IFN-gamma, TNF-alpha, IL-2, -4, -5, -10 and acidity) to discriminate between childhood asthma and controls. (2) The ability of these biomarkers to indicate asthma severity and control. METHODS: One-hundred and fourteen children were included: 64 asthmatics (10.7+/-3.0 years, 67.2% atopic) and 50 controls (10.0+/-0.4 years). Condensate was collected using a glass condenser. RESULTS: Exhaled nitric oxide, IFN-gamma and IL-4 in exhaled breath condensate differed significantly between asthma and controls. Multivariate backward logistic regression models demonstrated that IL-4 (odds ratio 7.9, 95% confidence interval 1.2-51.0) was the only significant indicator of an asthma diagnosis. Asthma control was best assessed by exhaled nitric oxide, 8-isoprostane, IFN-gamma and IL-4 (sensitivity 82%, specificity 80%, P<0.05), whereas exhaled nitric oxide, 8-isoprostane, nitrate and nitrite in condensate were the best indicators of asthma severity (sensitivity 89%, specificity 72%, P<0.05). CONCLUSION: Different markers in condensate are of an additional value to exhaled nitric oxide, and are needed in non-invasive inflammometry. They could be useful to diagnose asthma and to indicate asthma control and severity in childhood.

Breath condenser coatings affect measurement of biomarkers in exhaled breath condensate.

Exhaled breath condensate collection is not yet standardised and biomarker measurements are often close to lower detection limits. In the current study, it was hypothesised that adhesive properties of different condenser coatings interfere with measurements of eicosanoids and proteins in breath condensate. In vitro, condensate was derived from a collection model using two test solutions (8-isoprostane and albumin) and five condenser coatings (silicone, glass, aluminium, polypropylene and Teflon). In vivo, condensate was collected using these five coatings and the EcoScreen condenser to measure 8-isoprostane, and three coatings (silicone, glass, EcoScreen) to measure albumin. In vitro, silicone and glass coatings had significantly higher albumin recovery compared with the other coatings. A similar trend was observed for 8-isoprostane recovery. In vivo, median (interquartile range) 8-isoprostane concentrations were significantly higher using silicone (9.2 (18.8) pg.mL(-1)) or glass (3.0 (4.5) pg.mL(-1)) coating, compared with aluminium (0.5 (2.4) pg.mL(-1)), polypropylene (0.5 (0.5) pg.mL(-1)), Teflon (0.5 (0.0) pg.mL(-1)), and EcoScreen (0.5 (2.0) pg.mL(-1)). Albumin in vivo was mainly detectable using glass coating. In conclusion, a condenser with silicone or glass coating is more efficient for measurement of 8-isoprostane or albumin in exhaled breath condensate, than EcoScreen, aluminium, polypropylene or Teflon. Guidelines for exhaled breath condensate standardisation should include the most valid condenser coating to measure a specific biomarker.

Exhaled breath condensate: methodological recommendations and unresolved questions.

Collection of exhaled breath condensate (EBC) is a noninvasive method for obtaining samples from the lungs. EBC contains large number of mediators including adenosine, ammonia, hydrogen peroxide, isoprostanes, leukotrienes, nitrogen oxides, peptides and cytokines. Concentrations of these mediators are influenced by lung diseases and modulated by therapeutic interventions. Similarly EBC pH also changes in respiratory diseases. The aim of the American Thoracic Society/European Respiratory Society Task Force on EBC was to identify the important methodological issues surrounding EBC collection and assay, to provide recommendations for the measurements and to highlight areas where further research is required. Based on the currently available evidence and the consensus of the expert panel for EBC collection, the following general recommendations were put together for oral sample collection: collect during tidal breathing using a noseclip and a saliva trap; define cooling temperature and collection time (10 min is generally sufficient to obtain 1-2 mL of sample and well tolerated by patients); use inert material for condenser; do not use resistor and do not use filter between the subject and the condenser. These are only general recommendations and certain circumstances may dictate variation from them. Important areas for future research involve: ascertaining mechanisms and site of exhaled breath condensate particle formation; determination of dilution markers; improving reproducibility; employment of EBC in longitudinal studies; and determining the utility of exhaled breath condensate measures for the management of individual patients. These studies are required before recommending this technique for use in clinical practice.

[Allergic bronchopulmonary aspergillosis in asthma and cystic fibrosis]. / Allergische bronchopulmonale aspergillose bij astma en cystische fibrose.

Three children developed allergic bronchopulmonary aspergillosis (ABPA) as a complication of either asthma or cystic fibrosis (CF). The first patient was a 14-year-old boy with CF who presented with an episode of haemoptysis and a decrease in lung function. He was initially treated with intravenous antibiotics but there was no improvement of his lung function. After starting prednisone-itraconazole his condition improved substantially. The second patient was a 16-year-old girl with CF complicated by ABPA. She was treated for 2 years with prednisone-itraconazole. Although the symptoms worsened when the prednisone dosage was gradually reduced, her growth retardation and increased weight decided us to stop prednisone treatment. Two years later, her CF was once again complicated by ABPA. The third patientwas a 16-year-old boy with asthma who had initially been treated for an asthma exacerbation. In retrospect, the cause of his pulmonary exacerbation was probably an ABPA episode. These cases illustrate how important but also how difficult the early diagnosis of ABPA is, and the dilemmas faced in treatment to prevent the fibrotic end stage.

Chronic bronchiolitis in a 5-yr-old child after exposure to sulphur mustard gas.

Exposure to sulphur mustard (SM) gas may have extensive immediate effects on the respiratory system. However, long-term effects are far less known. This case report describes a Kurdish male child who was exposed to SM gas during a chemical attack in Iraq at 5 yrs of age. In the acute phase, the child developed severe respiratory symptoms with a chemical pneumonia. Extensive burning of the skin occurred. In the course of 10 yrs, lung function deteriorated progressively to a forced expiratory volume in one second of 30% of predicted value. Severe air-trapping occurred. The lung function abnormalities were not reversed by treatment with corticosteroids or bronchodilators. Infectious exacerbations of the child's lung disease occurred. High resolution computed tomography scan showed multiple bronchiectasis. The histological picture of an open lung biopsy was best described as a "chronic bronchiolitis".

[Guideline 'Treating asthma in children' for pediatric pulmonologists (2nd revised edition). I. Diagnosis and prevention]. / Richtlijn 'Astmabehandeling bij kinderen' van kinderlongartsen (2e herziening). I. Diagnostiek en preventie.

The case history and physical examination form the corner-stones for asthma diagnosis. Establishing the correct diagnosis may be difficult in infants and preschool children; in such cases the progression of the symptoms over time is important. Routine laboratory and radiological investigations are advised against. Allergy testing may be useful in children under the age of 4 years. Lung function investigations can be used from the age of 5 to 6 years onwards. Non-invasive investigations into the degree of bronchial inflammation can be performed by measuring the fraction nitric oxide in exhaled air. House dust mite reduction is a useful measure for preventing asthma if sensitisation has been demonstrated. Breast-feeding during the first 4 to 6 months of life can be considered as a preventive measure in infants with an increased risk of developing asthma and allergy.

Off-line sampling of exhaled air for nitric oxide measurement in children: methodological aspects.

Measurement of nitric oxide in exhaled air is a noninvasive method to assess airway inflammation in asthma. This study was undertaken to establish the reference range of exhaled NO in healthy school-aged children and to determine the influence of ambient NO, noseclip and breath-holding on exhaled NO, using an off-line balloon sampling method. All children attending a primary school (age range 8-13 yrs) underwent NO measurements on two occasions with high and low ambient NO. Each time, the children performed four expiratory manoeuvres into NO-impermeable balloons, with and without 10 s of breath-holding and with and without wearing a noseclip. Exhalation flow and pressure were not controlled. NO was measured within 4 h after collection, by means of chemiluminescence. All children completed a questionnaire on respiratory and allergic disorders, and performed flow/volume spirometry. With low ambient NO, the mean exhaled NO value of 72 healthy children with negative questionnaires and normal lung function was 5.1 +/- 0.2 parts per billion (ppb) versus a mean of 6.8 +/- 0.3 ppb in the remaining 49 children with positive questionnaires for asthma and allergy, and/or recent symptoms of cold (p=0.001). Exhaled and ambient NO were significantly related, especially with ambient NO > 10 ppb (r = 0.86, p=0.0001 versus r=0.34, p=0.004 for ambient values <10 ppb). The use of a noseclip, with low ambient NO and without breath-holding, caused a small decrease in exhaled NO values (p=0.001). The effect of breath-holding on exhaled NO depended on ambient NO. With ambient NO > 10 ppb, exhaled NO decreased, whereas with ambient NO < 10 ppb, exhaled NO increased after 10 s breath-hold. It is concluded that off-line sampling in balloons is a simple and, hence, attractive method for exhaled nitric oxide measurements in children which differentiates between groups with and without self-reported asthma, allergy and colds, when ambient nitric oxide is < 10 parts per billion. Wearing a noseclip and breath-holding affected measured values and should, therefore be standardized or, preferably, avoided.