Edward Dompeling

Mode and place of delivery, gastrointestinal microbiota, and their influence on asthma and atopy.

BACKGROUND Both gastrointestinal microbiota composition and cesarean section have been linked to atopic manifestations. However, results are inconsistent, and the hypothesized intermediate role of the microbiota in the association between birth mode and atopic manifestations has not been studied yet. OBJECTIVES We sought to investigate the relationship between microbiota composition, mode and place of delivery, and atopic manifestations. METHODS The Child, Parent and Health: Lifestyle and Genetic Constitution Birth Cohort Study included data on birth characteristics, lifestyle factors, and atopic manifestations collected through repeated questionnaires from birth until age 7 years. Fecal samples were collected at age 1 month (n = 1176) to determine microbiota composition, and blood samples were collected at ages 1 (n = 921), 2 (n = 822), and 6 to 7 (n = 384) years to determine specific IgE levels. RESULTS Colonization by Clostridium difficile at age 1 month was associated with wheeze and eczema throughout the first 6 to 7 years of life and with asthma at age 6 to 7 years. Vaginal home delivery compared with vaginal hospital delivery was associated with a decreased risk of eczema, sensitization to food allergens, and asthma. After stratification for parental history of atopy, the decreased risk of sensitization to food allergens (adjusted odds ratio, 0.52; 95% CI, 0.35-0.77) and asthma (adjusted odds ratio, 0.47; 95% CI, 0.29-0.77) among vaginally home-born infants was only found for children with atopic parents. Mediation analysis showed that the effects of mode and place of delivery on atopic outcomes were mediated by C difficile colonization. CONCLUSION Mode and place of delivery affect the gastrointestinal microbiota composition, which subsequently influences the risk of atopic manifestations.

Slowing the Deterioration of Asthma and Chronic Obstructive Pulmonary Disease Observed during Bronchodilator Therapy by Adding Inhaled Corticosteroids: A 4-Year Prospective Study

Rates of morbidity and mortality due to asthma and chronic obstructive pulmonary disease (COPD) have increased during the last two decades [1, 2]. These increases might be related to the use of bronchodilator therapy without anti-inflammatory medication [3, 4]. Recently, two studies found that regular bronchodilator treatment had adverse effects on the control of asthma [5] and the progression of asthma and COPD [6]. In a previous study of 160 patients with asthma or COPD [6], we found that continuous treatment with a bronchodilator (ipratropium bromide, 40 g, or salbutamol, 400 g, four times daily) was associated with a much higher annual decline in the forced expiratory volume in 1 second (FEV1) compared with treatment on demand. It is unclear whether an unfavorable course of asthma or COPD during bronchodilator therapy alone can be reversed or decelerated by additional anti-inflammatory therapy with inhaled corticosteroids. We studied 56 of the 160 patients who had an unfavorable disease course during bronchodilator therapy alone (an annual decline in FEV1 of at least 80 mL/y in combination with at least two exacerbations per year). These 56 patients (28 with asthma and 28 with COPD) were also treated with an inhaled corticosteroid (beclomethasone dipropionate, 800 g daily) during years 3 and 4 of the study. We assessed whether the worsening of their disease during bronchodilator therapy alone was reversed or decelerated by additional anti-inflammatory treatment with beclomethasone. The outcome measures were dynamic lung function indices (annual decline in pre- and postbronchodilator FEV1, peak expiratory flow rate [PEFR], and forced inspiratory volume in 1 second [FIV1]), static lung function indices (residual volume [RV], ratio of residual volume to total lung capacity (RV/TLC), inspiratory vital capacity [IVC]), nonspecific bronchial responsiveness (assessed by determining the concentration of histamine that provokes a 20% decrease in FEV1 [Pc 20]), exacerbations, and respiratory symptoms. Methods Patients Patient selection has been previously described [6]. In short, 29 family physicians in the catchment area of the University of Nijmegen, Nijmegen, the Netherlands, selected all patients who were 30 years or older and had symptoms of asthma or COPD. Only patients who showed mild-to-moderate airway obstruction (FEV1 > 50% of the predicted value [7]) or bronchial hyper-responsiveness to histamine (Pc 20 8 mg/mL) were included in the study. Patients dependent on inhaled corticosteroids who had chronic heart failure, malignant disorders, or other severe life-threatening diseases were excluded from the study. Of these patients, 160 (59 with asthma and 101 with COPD) completed the bronchodilator trial. During the 2 years of bronchodilator treatment, a rapid decline in FEV1 ( 80 mL/y) and a relatively high exacerbation rate ( 1/y) were observed in a subgroup of 56 patients (35%). Because of their unfavorable disease course, these patients were selected for additional treatment with inhaled beclomethasone for 2 years. The criteria for diagnosis of asthma or COPD were based on the standards of the American Thoracic Society [8]. Asthma was defined [6, 8] by a combination of factors: bronchial hyper-responsiveness to histamine (Pc 20 8 mg/mL); reversible obstruction (an improvement in FEV1 of more than 15% of the prebronchodilator value 60 minutes after the administration of both salbutamol, 400 g, and ipratropium bromide, 80 g); dyspnea; and allergy (defined as at least one positive result on seven radioallergosorbent tests that assessed sensitivity to pollen from weeds, grasses, and trees; cats and dogs; house dust mite; and Aspergillus fumigatus) or wheezing. Chronic obstructive pulmonary disease was defined [6, 8] by the combination of chronic cough or chronic sputum production for at least 3 months during at least 2 consecutive years; and continuous bronchus obstruction (FEV1 85% of the predicted value). The separate features of asthma and COPD overlap (for instance, some asthmatic patients had chronic cough, and some COPD patients had a Pc 20 8 mg/mL), but the definitions based on feature combinations ensured that no patients with asthma also had COPD and vice versa [6]. The study was approved by the Medical Ethics Committee of the University of Nijmegen. All patients gave informed consent. Study Design and Treatment At the start of the 4-year intervention study, the patients were randomly assigned to one of two parallel treatment regimens: continuous bronchodilator therapy (four times daily) or treatment on demand (dry powder inhalations during symptomatic periods) [6]. The patients used salbutamol, 400 g, during 1 year and ipratropium bromide, 40 g, during the other year; both were administered as dry powder inhalations. The sequence of the drugs was determined by random allocation. During years 3 and 4, the 56 patients received 400 g of beclomethasone, two times daily, in combination with 400 g of salbutamol or 40 g of ipratropium bromide, four times daily (all dry powder inhalations). The bronchodilator inhaled during year 2 was also used in years 3 and 4. During the first 2 years of the study, 27 of the 56 patients received bronchodilator therapy on demand (of the 27, 15 had asthma and 12 had COPD). For patients treated on demand, the mean (SE) daily number of dry powder inhalations of salbutamol or ipratropium bromide was 1.2 0.3 in those with asthma and 0.8 0.2 in those with COPD. During years 3 and 4, 28 patients received salbutamol (15 with asthma and 13 with COPD) and 28 received ipratropium bromide (13 with asthma and 15 with COPD). Once every 3 months, inhalation technique and compliance with the prescribed medication were checked. Patients were instructed to rinse their mouths after the dry powder inhalations. During the second year of beclomethasone therapy, a single-blind prospective study was done to assess patient compliance with beclomethasone and the additional bronchodilator. Compliance was measured by counting capsules at the end of a 4-month period. Patients were unaware that their medication was counted after this period. Lung Function, Nonspecific Bronchial Responsiveness, and Reversibility All measurements were carried out by two qualified laboratory assistants during exacerbation-free periods. No bronchodilator was inhaled for at least 8 hours before the pulmonary function tests. At the start and after 24 and 48 months of the study, the inspiratory vital capacity (IVC), residual volume (RV), functional residual capacity (FRC), and total lung capacity (TLC) were assessed using the wet Gould spirometer (Sensormedics, Bilthoven, the Netherlands) according to the standards of the European Coal and Steel Community [7]. The FEV1, bronchial responsiveness to histamine, and the reversibility of airway obstruction were assessed at 6-month intervals using the Microspiro HI-298 (Chest Corporation, Tokyo, Japan) [9]. Moreover, FEV1 and reversibility were also assessed after 1 and 13 months of study [6]. The best of three forced expiratory maneuvers, with the highest sum of the forced vital capacity (FVC) and FEV1, was used for data analysis. The bronchial responsiveness to histamine was measured according to the method described by Cockcroft and colleagues [10]. Results were expressed as the concentration of histamine that provoked a 20% decrease in FEV1 (Pc 20). After the FEV1 had returned to the baseline value, the bronchodilating response (reversibility) was assessed 60 minutes after the administration of both 80 g of ipratropium bromide and 400 g of salbutamol (metered dose aerosol) [6]. The bronchodilating response was expressed as the increase in FEV1 relative to the predicted value of the FEV1. Peak Expiratory Flow Assessments Once a week (on the same day and at the same time), peak expiratory flow rate (PEFR) was measured with the Assess peak flow meter (HealthScan Products, Cedar Grove, New Jersey) [11] in the morning and in the evening. The highest value of three measurements was included in the analysis. The diurnal PEFR index (absolute difference between the evening value and the morning value divided by the highest value) was calculated. Exacerbations Our definition of exacerbation was based on that of Fletcher as modified by Boman and colleagues [12]. When an exacerbation occurred, a 10-day course of oral prednisone was administered. Patients received 25 mg for 2 days, 20 mg for 2 days, 15 mg for 2 days, and so forth. Symptoms and Adverse Effects Using a scale of 0 to 4, all patients recorded, on a weekly basis, the presence and severity of symptoms (cough, phlegm, dyspnea, fatigue, disturbed sleep at night). The adverse effects of medication (dysphonia and oropharyngeal irritation) were recorded by the patients once every 3 months. Moreover, every 6 months, the presence and severity of oral candidiasis were assessed using a questionnaire (no, light, or severe symptoms). Smoking At the start of the study, smoking history was assessed in pack-years. During the study, the average number of cigarettes smoked per day was also recorded in weekly diary entries. Power Calculations Assuming that the clinically relevant, decreased annual decline in FEV1 during beclomethasone treatment is 25 mL/y and that the residual standard deviation is 50 mL/y, the coefficient of variation is 25/50 or 0.5. Based on an of 0.05 and a of 0.20 (power:1 0.2, or 0.8), the required number of patients for the study would be 51. Based on an estimated dropout rate of 10%, the required initial number of study patients would be 56. Statistical Analysis Data on outcome variables obtained before and during beclomethasone therapy were compared. Differences were tested by repeated-measures analysis of variance, the paired Student t-test for normally distributed variables, and the Wilcoxon paired signed-rank test for non-normally distributed variables. Before the analysis, the Pc 20 values were 2log transformed. The an

Exhaled breath condensate in children: Pearls and pitfalls

Exhaled breath condensate (EBC) is a rapidly growing field of research in respiratory medicine. Airway inflammation is a central feature of chronic lung diseases, like asthma, cystic fibrosis, bronchopulmonary dysplasia and primary ciliary dyskinesia. EBC may be a useful technique for non‐invasive assessment of markers of airway inflammation. The non‐invasive character of EBC ‘inflammometry’ and the general lack of appropriate techniques makes it particularly interesting for paediatrics.

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.

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.

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.

Clinical use of exhaled volatile organic compounds in pulmonary diseases: a systematic review.

There is an increasing interest in the potential of exhaled biomarkers, such as volatile organic compounds (VOCs), to improve accurate diagnoses and management decisions in pulmonary diseases. The objective of this manuscript is to systematically review the current knowledge on exhaled VOCs with respect to their potential clinical use in asthma, lung cancer, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), and respiratory tract infections. A systematic literature search was performed in PubMed, EMBASE, Cochrane database, and reference lists of retrieved studies. Controlled, clinical, English-language studies exploring the diagnostic and monitoring value of VOCs in asthma, COPD, CF, lung cancer and respiratory tract infections were included. Data on study design, setting, participant characteristics, VOCs techniques, and outcome measures were extracted. Seventy-three studies were included, counting in total 3,952 patients and 2,973 healthy controls. The collection and analysis of exhaled VOCs is non-invasive and could be easily applied in the broad range of patients, including subjects with severe disease and children. Various research groups demonstrated that VOCs profiles could accurately distinguish patients with a pulmonary disease from healthy controls. Pulmonary diseases seem to be characterized by a disease specific breath-print, as distinct profiles were found in patients with dissimilar diseases. The heterogeneity of studies challenged the inter-laboratory comparability. In conclusion, profiles of VOCs are potentially able to accurately diagnose various pulmonary diseases. Despite these promising findings, multiple challenges such as further standardization and validation of the diverse techniques need to be mastered before VOCs can be applied into clinical practice.

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 (H2O2), 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, H2O2 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 µL, 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 H2O2, 8-isoprostane, interleukin-2, -4, -5 and -13, and tumour necrosis factor-α. Isoprostane concentrations were significantly higher using the new condenser, whereas H2O2 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.

Cytokines in exhaled breath condensate of children with asthma and cystic fibrosis.

BACKGROUND Inflammatory mediators in exhaled breath condensate (EBC) indicate ongoing inflammation in the lungs and might differentiate between asthma and cystic fibrosis (CF). OBJECTIVES To evaluate the presence, concentration, and short-term variability of TH1- and TH2-mediated cytokines (interferon-gamma [IFN-gamma], tumor necrosis factor alpha [TNF-alpha], interleukin 10 [IL-10], IL-5, IL-4, and IL-2) in EBC of children with asthma or CF and in controls and to analyze the discriminating ability of inflammatory markers in EBC between children with asthma or CF and controls. METHODS Expired air was conducted through a double-jacketed glass tube cooled by circulating ice water. In 33 asthmatic children, 12 children with CF, and 35 control children, EBC was collected during tidal breathing. Cytokines were measured using flow cytometry. RESULTS Interleukin 2, IL-4, IFN-gamma, and IL-10 were detected in 16%, 16%, 11%, and 9%, respectively, of all samples in asthma and CF. Interleukin 5 and TNF-alpha were not detected in children with CF. Cytokine concentrations did not differ significantly in children with asthma vs CF. In controls, IFN-gamma, TNF-alpha, and IL-10 were detected in 9%, 14%, and 3%, respectively; IL-2, IL-4, and IL-5 were not detected in controls. CONCLUSIONS Cytokines such as IFN-gamma, TNF-alpha, IL-10, IL-5, IL-4, and IL-2 can be detected in EBC of children with asthma or CF. However, the concentrations found are close to the detection limits of the assay used. These findings emphasize the importance of developing more sensitive techniques for the analysis of EBC and of standardizing the EBC collection method.

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.