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.

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".

['Inflammometry' with nitric oxide in exhaled air: a new test for lung diseases]. / 'Inflammometrie' met stikstofmonoxide in uitademingslucht: een nieuw onderzoek bij longaandoeningen.

The gas nitric oxide (NO) is produced in increased amounts in certain types of inflammatory responses and its presence in exhaled air can be demonstrated. The nitric oxide fraction in exhaled air (FeNO) is elevated in patients with asthma and lowered in the case of several other lung diseases such as cystic fibrosis and primary ciliary dyskinesia. The FeNO can be quickly measured in a non-invasive and reproducible manner: on-line if the patient (adult or child), having taken a deep breath in, breathes out with a low flow rate into the NO measuring device or off-line if the expired air is collected in an NO inert reservoir. Confounding factors are contamination of inhaled air with ambient NO and contamination of exhaled air with NO that has been produced in the paranasal sinuses and the nose. The possible applications of FeNO measurement as a new lung function test include diagnostic tests for chronic respiratory symptoms and the possible guidance of anti-inflammatory therapy for asthma and, perhaps, other respiratory disorders.

Hydrogen peroxide and nitric oxide in exhaled air of children with cystic fibrosis during antibiotic treatment.

Cystic fibrosis (CF) patients characteristically have severe chronic airway inflammation associated with bacterial infection. A noninvasive marker of airway inflammation could be a useful guide to treatment of CF lung disease. The aim of this study was to assess whether measurement of hydrogen peroxide (H2O2) and nitric oxide (NO) in exhaled air can serve to monitor the effect of treatment with antibiotics in CF-children with acute infective pulmonary exacerbations. Sixteen CF-patients (mean age 12.3 yrs) with exacerbation of their lung infection were treated with intravenous antibiotics in an uncontrolled study. During treatment, H2O2 in exhaled air condensate was measured twice a week. In addition, serial NO measurements were performed in nine patients. During antibiotic treatment the median H2O2 concentration in exhaled air condensate decreased significantly from 0.28 microM (range 0.07-1.20 microM) to 0.16 microM (range 0.05-0.24 microM, p=0.002) and the mean forced expiratory volume in one second significantly increased from 55% predicted to 75% pred (p=0.001). In individual subjects, changes of H2O2 and FEV1 between pairs of serial measurements correlated weakly (p=0.08). Data on exhaled NO were inconclusive; exhaled NO did not change systematically during treatment. It is concluded that cystic fibrosis patients with an acute pulmonary exacerbation have abnormally high concentrations of hydrogen peroxide, but not of nitric oxide, in exhaled air, which decrease during intravenous antibiotic treatment. Further controlled studies should establish if exhaled hydrogen peroxide, may serve as a noninvasive parameter of airway inflammation to guide antibiotic treatment in cystic fibrosis lung disease.

Flow-dependency of exhaled nitric oxide in children with asthma and cystic fibrosis.

The concentration of nitric oxide in exhaled air, a marker of airway inflammation, depends critically on the flow of exhalation. Therefore, the aim of this study was to determine the effect of varying the flow on end-expiratory NO concentration and NO output in children with asthma or cystic fibrosis (CF) and in healthy children. Nineteen children with stable asthma, 10 with CF, and 20 healthy children exhaled from TLC while controlling expiratory flow by means of a biofeedback signal at approximately 2, 5, 10 and 20% of their vital capacity per second. NO was measured in exhaled air with a chemiluminescence analyser. Comparisons between the three groups were made by analysing the NO concentration at the endexpiratory plateau and by calculating NO output at different flows. Exhaled NO decreased with increasing flow in all children. Children with asthma had significantly higher NO concentrations than healthy children, but only at the lowest flows. Asthmatics using inhaled steroids (n=13) tended to have lower median exhaled NO than those without steroids. The slope of linearized (log-log transformed) NO/flow plots was significantly steeper in asthmatics than in healthy controls. CF patients had a significantly lower NO concentration and output over the entire flow range studied, compared to asthmatic and control subjects, with a similar NO/flow slope as control subjects. In conclusion, the nitric oxide concentration in exhaled air is highly flow-dependent, and the nitric oxide-flow relationship differs between asthmatics versus cystic fibrosis patients and control subjects. Assessment of the nitric oxide/flow relationship may help in separating asthmatics from normal children.