Breathomics for Assessing the Effects of Treatment and Withdrawal With Inhaled Beclomethasone/Formoterol in Patients With COPD.

Background: Prospective pharmacological studies on breathomics profiles in COPD patients have not been previously reported. We assessed the effects of treatment and withdrawal of an extrafine inhaled corticosteroid (ICS)-long-acting ß2-agonist (LABA) fixed dose combination (FDC) using a multidimensional classification model including breathomics. Methods: A pilot, proof-of-concept, pharmacological study was undertaken in 14 COPD patients on maintenance treatment with inhaled fluticasone propionate/salmeterol (500/50 µg b.i.d.) for at least 8 weeks (visit 1). Patients received 2-week treatment with inhaled beclomethasone dipropionate/formoterol (100/6 µg b.i.d.) (visit 2), 4-week treatment with formoterol alone (6 µg b.i.d.) (visit 3), and 4-week treatment with beclomethasone/formoterol (100/6 µg b.i.d.) (visit 4). Exhaled breath analysis with two e-noses, based on different technologies, and exhaled breath condensate (EBC) NMR-based metabolomics were performed. Sputum cell counts, sputum supernatant and EBC prostaglandin E2 (PGE2) and 15-F2t-isoprostane, fraction of exhaled nitric oxide, and spirometry were measured. Results: Compared with formoterol alone, EBC acetate and sputum PGE2, reflecting airway inflammation, were reduced after 4-week beclomethasone/formoterol. Three independent breathomics techniques showed that extrafine beclomethasone/formoterol short-term treatment was associated with different breathprints compared with regular fluticasone propionate/salmeterol. Either ICS/LABA FDC vs. formoterol alone was associated with increased pre-bronchodilator FEF25-75% and FEV1/FVC (P = 0.008-0.029). The multidimensional model distinguished fluticasone propionate/salmeterol vs. beclomethasone/formoterol, fluticasone propionate/salmeterol vs. formoterol, and formoterol vs. beclomethasone/formoterol (accuracy > 70%, P < 0.01). Conclusions: Breathomics could be used for assessing ICS treatment and withdrawal in COPD patients. Large, controlled, prospective pharmacological trials are required to clarify the biological implications of breathomics changes. EUDRACT number: 2012-001749-42.

The discovery and development of aclidinium bromide for the treatment of chronic obstructive pulmonary disease.

INTRODUCTION: Bronchodilators, including long-acting muscarinic receptor antagonists (LAMAs), are a mainstay of the pharmacological treatment of chronic obstructive pulmonary disease (COPD). LAMAs act as bronchodilators principally by antagonizing airway smooth muscle cells M3 muscarinic receptors. Aclidinium bromide is a twice-daily LAMA which was developed to improve on the efficacy and/or safety of previous LAMAs. Area covered: Herein, the authors present the pharmacotherapeutic role of aclidinium in COPD and point out unmet need in this research area. The following aspects are covered: a) the discovery and medicinal chemistry of aclidinium bromide; b) an overview of the market; c) its mechanism of action; d) its pharmacokinetic/pharmacodynamic profile derived from pre-clinical studies; e) the clinical studies which led to its licensing; f) the evidence from meta-analyses; g) the aclidinium/formoterol fixed dose combination for COPD and h) priorities in this area of research. Expert opinion: Aclidinium bromide has the pharmacological properties, safety and efficacy profile and inhaler characteristics which makes it a valuable therapeutic option for pharmacological management of patients with COPD. Due to its rapid biotransformation into inactive metabolites, aclidinium is potentially one of the safest LAMAs. Further head-to-head randomized clinical trials are required to define efficacy and safety of aclidinium when compared to once-daily LAMAs. The clinical relevance of airway anti-remodeling effects of aclidinium has to be defined.

Primary Biliary Cholangitis Associated with Skin Disorders: A Case Report and Review of the Literature.

Primary biliary cholangitis (PBC) is a rare autoimmune cholestatic liver disease. It is often associated with extrahepatic autoimmune diseases. Skin disorders are sporadically reported in association with PBC. We report an unusual case of PBC associated with acquired reactive perforating dermatosis (ARPD) and present a review of the literature on skin disorders associated with PBC. Our patient presented to the dermatology department with generalized pruritus associated with nodular perforating skin lesions on the trunk, and cholestatic liver disease of unknown origin. After having established both diagnosis of ARPD and PBC, she was managed in an interdisciplinary manner, and both her skin and liver conditions improved gradually. Only one similar case is reported in the literature, in that case, the liver disease was not treated. By reviewing the literature, we found that lichen planus, vitiligo, and psoriasis are the most frequent skin disorders associated with PBC. However, there is only limited data about specific skin disorders associated with PBC. This case report of a patient with PBC associated with ARPD underlines the importance of interdisciplinary management of patients with rare liver diseases combined with rare skin disorders. The present review of the literature shows that probably, immune-mediated skin conditions are not more frequent in PBC patients than in the general population. However, the available data are scant; there is a need for high-quality data on skin conditions associated with PBC.

Dupilumab for the treatment of asthma.

INTRODUCTION: Dupilumab (REGN668/SAR231893), produced by a collaboration between Regeneron and Sanofi, is a monoclonal antibody currently in phase III for moderate-to-severe asthma. Dupilumab is directed against the α-subunit of the interleukin (IL)-4 receptor and blocks the IL-4 and IL-13 signal transduction. Areas covered: Pathophysiological role of IL-4 and IL-13 in asthma; mechanism of action of dupilumab; pharmacology of IL-4 receptor; phase I and phase II studies with dupilumab; regulatory affairs. Expert opinion: Patients with severe asthma who are not sufficiently controlled with standard-of-care represent the target asthma population for dupilumab. If confirmed, efficacy of dupilumab in both eosinophilic and non-eosinophilic severe asthma phenotype might represent an advantage over approved biologics for asthma, including omalizumab, mepolizumab, and reslizumab. Head-to-head studies to compare dupilumab versus other biologics with different mechanism of action are required. Pediatric studies with dupilumab are currently lacking and should be undertaken to assess efficacy and safety of this drug in children with severe asthma. The lack of preclinical data and published results of the completed four phase I studies precludes a complete assessment of the pharmacological profile of dupilumab. Dupilumab seems to be generally well tolerated, but large studies are required to establish its long-term safety and tolerability.

Nailfold capillaroscopic parameters and skin telangiectasia patterns in patients with systemic sclerosis.

OBJECTIVE: To correlate nailfold capillaroscopic parameters with the presence of skin telangiectases (TAs) in systemic sclerosis patients (SSc). METHODS: Thirty-three consecutive patients (28 women and 5 men, mean age 59±21years) affected by SSc according to the ACR/EULAR criteria, 30 with limited (lcSSc) and 3 with diffuse (dcSSc) skin disease, displaying the presence of skin TAs on face, hands, forearms, neck, and décolleté were recruited. Nailfold videocapillaroscopy (NVC) was performed to classify the patients into one of the three main patterns of SSc microangiopathy ("early", "active", "late"), and to calculate the microangiopathy evolution score (MES). SSc patients underwent also dermoscopy (DS) for the analysis of the TA score and patterns (spot or reticular). Possible correlations between clinical findings, serum autoantibodies, TA patterns and both NVC patterns and MES were investigated. RESULTS: The "late" NVC pattern was found associated with a highest total number of TAs (p=0.005): in particular both "spot" and "reticular" TA patterns were found equally distributed in SSc patients with the "late" pattern. High MES values were found associated with the highest total number of TAs (p=0.003), with the "reticular" but not with the "spot" DS pattern (p=0.003) and with the "late" pattern of microangiopathy (p=0.001). CONCLUSIONS: The severity of nailfold microangiopathy seems to correlate in SSc patients with both progressive cutaneous microvascular abnormalities and Medsger's severity score, as evaluated by NVC analysis and DS. The assessment of the microvascular damage may be useful not only during the onset of SSc for the early diagnosis, but also to monitor its evolution.

Skin lesion image segmentation using Delaunay Triangulation for melanoma detection.

Developing automatic diagnostic tools for the early detection of skin cancer lesions in dermoscopic images can help to reduce melanoma-induced mortality. Image segmentation is a key step in the automated skin lesion diagnosis pipeline. In this paper, a fast and fully-automatic algorithm for skin lesion segmentation in dermoscopic images is presented. Delaunay Triangulation is used to extract a binary mask of the lesion region, without the need of any training stage. A quantitative experimental evaluation has been conducted on a publicly available database, by taking into account six well-known state-of-the-art segmentation methods for comparison. The results of the experimental analysis demonstrate that the proposed approach is highly accurate when dealing with benign lesions, while the segmentation accuracy significantly decreases when melanoma images are processed. This behavior led us to consider geometrical and color features extracted from the binary masks generated by our algorithm for classification, achieving promising results for melanoma detection.

Investigational prostaglandin D2 receptor antagonists for airway inflammation.

INTRODUCTION: By activating DP1 and DP2 receptors on immune and non-immune cells, prostaglandin D2 (PGD2), a major metabolic product of cyclo-oxygenase pathway released after IgE-mediated mast cell activation, has pro-inflammatory effects, which are relevant to the pathophysiology of allergic airway disease. At least 15 selective, orally active, DP2 receptor antagonists and one DP1 receptor antagonist (asapiprant) are under development for asthma and/or allergic rhinitis. AREAS COVERED: In this review, the authors cover the pharmacology of PGD2 and PGD2 receptor antagonists and look at the preclinical, phase I and phase II studies with selective DP1 and DP2 receptor antagonists. EXPERT OPINION: Future research should aim to develop once daily compounds and increase the drug clinical potency which, apart from OC000459 and ADC-3680, seems to be relatively low. Further research and development of DP2 receptor antagonists is warranted, particularly in patients with severe uncontrolled asthma, whose management is a top priority. Pediatric studies, which are not available, are required for assessing the efficacy and safety of this novel drug class in children with asthma and allergic rhinitis. Studies on the efficacy of DP2 receptor antagonists in various asthma phenotypes including: smokers, obese subjects, early vs late asthma onset, fixed vs reversible airflow limitation, are required for establishing their pharmacotherapeutic role.

Exhaled and non-exhaled non-invasive markers for assessment of respiratory inflammation in patients with stable COPD and healthy smokers.

We aimed at comparing exhaled and non-exhaled non-invasive markers of respiratory inflammation in patients with chronic obstructive pulmonary disease (COPD) and healthy subjects and define their relationships with smoking habit. Forty-eight patients with stable COPD who were ex-smokers, 17 patients with stable COPD who were current smokers, 12 healthy current smokers and 12 healthy ex-smokers were included in a cross-sectional, observational study. Inflammatory outcomes, including prostaglandin (PG) E2 and 15-F2t-isoprostane (15-F2t-IsoP) concentrations in exhaled breath condensate (EBC) and sputum supernatants, fraction of exhaled nitric oxide (FENO) and sputum cell counts, and functional (spirometry) outcomes were measured. Sputum PGE2 was elevated in both groups of smokers compared with ex-smoker counterpart (COPD: P < 0.02; healthy subjects: P < 0.03), whereas EBC PGE2 was elevated in current (P = 0.0065) and ex-smokers with COPD (P = 0.0029) versus healthy ex-smokers. EBC 15-F2t-IsoP, a marker of oxidative stress, was increased in current and ex-smokers with COPD (P < 0.0001 for both) compared with healthy ex-smokers, whereas urinary 15-F2t-IsoP was elevated in both smoker groups (COPD: P < 0.01; healthy subjects: P < 0.02) versus healthy ex-smokers. FENO was elevated in ex-smokers with COPD versus smoker groups (P = 0.0001 for both). These data suggest that the biological meaning of these inflammatory markers depends on type of marker and biological matrix in which is measured. An approach combining different types of outcomes can be used for assessing respiratory inflammation in patients with COPD. Large studies are required to establish the clinical utility of this strategy.

Electronic Nose and Exhaled Breath NMR-based Metabolomics Applications in Airways Disease.

Breathomics, the multidimensional molecular analysis of exhaled breath, includes analysis of exhaled breath with gas-chromatography/mass spectrometry (GC/MS) and electronic noses (e-noses), and metabolomics of exhaled breath condensate (EBC), a non-invasive technique which provides information on the composition of airway lining fluid, generally by high-resolution nuclear magnetic resonance (NMR) spectroscopy or MS methods. Metabolomics is the identification and quantification of small molecular weight metabolites in a biofluid. Specific profiles of volatile compounds in exhaled breath and metabolites in EBC (breathprints) are potentially useful surrogate markers of inflammatory respiratory diseases. Electronic noses (e-noses) are artificial sensor systems, usually consisting of chemical cross-reactive sensor arrays for characterization of patterns of breath volatile compounds, and algorithms for breathprints classification. E-noses are handheld, portable, and provide real-time data. E-nose breathprints can reflect respiratory inflammation. E-noses and NMR-based metabolomics of EBC can distinguish patients with respiratory diseases such as asthma, COPD, and lung cancer, or diseases with a clinically relevant respiratory component including cystic fibrosis and primary ciliary dyskinesia, and healthy individuals. Breathomics has also been reported to identify patients affected by different types of respiratory diseases. Patterns of breath volatile compounds detected by e-nose and EBC metabolic profiles have been associated with asthma phenotypes. In combination with other -omics platforms, breathomics might provide a molecular approach to respiratory disease phenotyping and a molecular basis to tailored pharmacotherapeutic strategies. Breathomics might also contribute to identify new surrogate markers of respiratory inflammation, thus, facilitating drug discovery. Validation in newly recruited, prospective independent cohorts is essential for development of e-nose and EBC NMRbased metabolomics techniques.

Liquid chromatography-mass spectrometry measurement of leukotrienes in asthma and other respiratory diseases.

Leukotrienes (LTs), including cysteinyl-LTs (LTC4, LTD4 and LTE4) and LTB4, are potent inflammatory lipid mediators which have been involved in the pathophysiology of respiratory diseases. LC-MS/MS techniques for measuring LT concentrations in sputum supernatants, serum, urine and exhaled breath condensate (EBC) have been developed. In asthmatic adults, reported LTB4 and LTE4 concentrations in sputum range from 79 to 7,220 pg/ml and from 11.9 to 891 pg/ml, respectively. Data on sputum LT concentrations in healthy subjects are not available. In EBC, reported LTE4 concentrations range from 38 to 126 pg/ml (95% CI) in adult asthma patients and from 34 to 48 pg/ml in healthy subjects. LTB4 concentrations in EBC range from 175 to 315 pg/ml (interquartile range) in asthmatic children, and from 25 to 245 pg/ml in healthy children. Enabling an accurate quantitative assessment of LTs in biological fluids, LC-MS/MS techniques provide a valuable tool for exploring the pathophysiological role of LTs in respiratory disease and might be useful for assessing the effects of therapeutic intervention. This review presents the analytical aspects of the LC-MS/MS techniques for measuring LT concentrations in biological fluids and discusses their potential utility for the assessment of airway inflammation and monitoring of pharmacological treatment in patients with asthma phenotypes and other respiratory diseases.

Within-day and between-day repeatability of measurements with an electronic nose in patients with COPD.

Electronic noses (e-noses), artificial sensor systems generally consisting of chemical sensor arrays for the detection of volatile compound profiles, have potential applications in respiratory medicine. We assessed within-day and between-day repeatability of an e-nose made from 32 sensors in patients with stable chronic obstructive pulmonary disease (COPD). We also compared between-day repeatability of an e-nose, fraction of exhaled nitric oxide (FENO) and pulmonary function testing. Within-day and between-day repeatability for the e-nose was assessed in two breath samples collected 30 min and seven days apart, respectively. Repeatability was expressed as an intraclass correlation coefficient (ICC). All sensors had ICC above 0.5, a value that is considered acceptable for repeatability. Regarding within-day repeatability, ICC ranged from 0.75 to 0.84 (mean = 0.80 ± 0.004). Sensors 6 and 19 were the most reproducible sensors (both, ICC = 0.84). Regarding between-day repeatability, ICC ranged from 0.57 to 0.76 (mean = 0.68 ± 0.01). Sensor 19 was the most reproducible sensor (ICC = 0.76). Within-day e-nose repeatability was greater than between-day repeatability (P < 0.0001). Between-day repeatability of FENO (ICC = 0.91) and spirometry (ICC range = 0.94-0.98) was greater than that of e-nose (mean ICC = 0.68). In patients with stable COPD, the e-nose used in this study has acceptable within-day and between-day repeatability which varies between different sensors.

The electronic nose in respiratory medicine.

Several volatile organic compounds have been identified in exhaled breath in healthy subjects and patients with respiratory diseases by gas chromatography/mass spectrometry. Identification of selective patterns of volatile organic compounds in exhaled breath could be used as a biomarker of inflammatory lung diseases. An electronic nose (e-nose) is an artificial sensor system that generally consists of an array of chemical sensors for detection of volatile organic compound profiles (breathprints) and an algorithm for pattern recognition. E-noses are handheld, portable devices that provide immediate results. E-noses discriminate between patients with respiratory disease, including asthma, COPD and lung cancer, and healthy control subjects, and also among patients with different respiratory diseases. E-nose breathprints are associated with airway inflammation activity. In combination with other 'omics' platforms, e-nose technology might contribute to the identification of new surrogate markers of pulmonary inflammation and subphenotypes of patients with respiratory diseases, provide a molecular basis to a personalized pharmacological treatment, and facilitate the development of new drugs.

Diagnostic performance of an electronic nose, fractional exhaled nitric oxide, and lung function testing in asthma.

BACKGROUND: Analysis of exhaled breath by biosensors discriminates between patients with asthma and healthy subjects. An electronic nose consists of a chemical sensor array for the detection of volatile organic compounds (VOCs) and an algorithm for pattern recognition. We compared the diagnostic performance of a prototype of an electronic nose with lung function tests and fractional exhaled nitric oxide (FENO) in patients with atopic asthma. METHODS: A cross-sectional study was undertaken in 27 patients with intermittent and persistent mild asthma and in 24 healthy subjects. Two procedures for collecting exhaled breath were followed to study the differences between total and alveolar air. Seven patients with asthma and seven healthy subjects participated in a study with mass spectrometry (MS) fingerprinting as an independent technique for assessing between group discrimination. Classification was based on principal component analysis and a feed-forward neural network. RESULTS: The best results were obtained when the electronic nose analysis was performed on alveolar air. Diagnostic performance for electronic nose, FENO, and lung function testing was 87.5%, 79.2%, and 70.8%, respectively. The combination of electronic nose and FENO had the highest diagnostic performance for asthma (95.8%). MS fingerprints of VOCs could discriminate between patients with asthma and healthy subjects. CONCLUSIONS: The electronic nose has a high diagnostic performance that can be increased when combined with FENO. Large studies are now required to definitively establish the diagnostic performance of the electronic nose. Whether this integrated noninvasive approach will translate into an early diagnosis of asthma has to be clarified. TRIAL REGISTRATION: EUDRACT https://eudralink.emea.europa.eu; Identifier: 2007-000890-51; and clinicaltrials.gov; Identifier: NCT00819676.

Effects of montelukast treatment and withdrawal on fractional exhaled nitric oxide and lung function in children with asthma.

BACKGROUND: Leukotriene receptor antagonists (LTRAs) reduce fractional exhaled nitric oxide (Feno) concentrations in children with asthma, but the effect of LTRA withdrawal on Feno and lung function is unknown. We aimed to study the effect of treatment and withdrawal of montelukast, a LTRA, on airway inflammation as reflected by Feno and lung function in children with asthma. METHODS: A double-blind, randomized, placebo controlled, parallel group study was undertaken in 14 atopic children with mild persistent asthma who were treated with oral montelukast (5 mg/d for 4 weeks) and 12 atopic children with mild persistent asthma who received matching placebo. A follow-up visit was performed 2 weeks after montelukast or placebo withdrawal. RESULTS: Montelukast reduced Feno concentrations by 17% (p = 0.067), an effect that was more pronounced (35%) [p = 0.0029] when children with seasonal atopy who were exposed to relevant allergens during the treatment phase were excluded from analysis (n = 3). Compared to those at the end of treatment, Feno concentrations were increased 2 weeks after montelukast withdrawal (p = 0.023) concomitant with a reduction in absolute FEV(1) values (p = 0.011), FEV(1) percentage of predicted values (p = 0.006), FEV(1)/FVC ratio (p = 0.002), and forced expiratory flow at 25% to 75% of FVC values (p = 0.021). These changes were not observed in the placebo group. CONCLUSIONS: LTRAs reduce Feno concentrations in children with asthma, and withdrawal can result in increased Feno values and worsening of lung function in children with asthma.

Effects of a leukotriene receptor antagonist on exhaled leukotriene E4 and prostanoids in children with asthma.

BACKGROUND: Leukotriene (LT) E(4) and 8-isoprostane concentrations are elevated in exhaled breath condensate in children with asthma. The effects of leukotriene receptor antagonists (LTRAs) on exhaled leukotriene and prostanoids in children with asthma are unknown. OBJECTIVE: (1) To study the effect of montelukast, a LTRA, on exhaled LTE(4), 8-isoprostane, and prostaglandin E(2) in children with asthma and atopic children; (2) to measure exhaled nitric oxide. METHODS: An open-label study with oral montelukast (5 mg once daily for 4 weeks) was undertaken in 17 atopic children with asthma and 16 atopic children without asthma. RESULTS: Pretreatment exhaled LTE(4) (P < .0001) and 8-isoprostane (P < .0001) values were higher in atopic children with asthma than in atopic children without asthma. In atopic children with asthma, montelukast reduced exhaled LTE(4) by 33% (P < .001), and this reduction was correlated with pretreatment LTE(4) values (r = -0.90; P = .0001). Posttreatment exhaled LTE(4) levels in children with asthma were higher than pretreatment LTE(4) values in atopic children without asthma (P < .004). Montelukast had no effect on exhaled LTE(4) in atopic children without asthma (P = .74), or on exhaled 8-isoprostane (atopic children with asthma, P = .94; atopic children without asthma, P = .55) and PGE(2) (atopic children with asthma, P = .56; atopic children without asthma, P = .93) in both groups. In atopic children with asthma, exhaled nitric oxide concentrations were reduced by 27% (P < .05) after montelukast. CONCLUSION: Leukotriene receptor antagonists decrease exhaled LTE(4) in atopic children with asthma. This reduction is dependent on baseline exhaled LTE(4) values. CLINICAL IMPLICATIONS: Measurement of exhaled LTE(4) might help identify children with asthma most likely to benefit from LTRAs.

Delayed allergic reaction to suxamethonium driven by oligoclonal Th1-skewed CD4+CCR4+IFN-gamma+ memory T cells.

BACKGROUND: Muscle relaxants represent the drugs most frequently involved in intraoperative anaphylaxis during surgical procedures. Our aim was to report the case of a delayed reaction to suxamethonium and analyze specific T cell lines with regard to their specificity, phenotype and cytokine profile. METHODS: We generated a drug-specific T cell line from a biopsy at the site of positive intradermal reactions and analyzed the immunophenotype, T cell receptor Vbeta domain expression and cytokine profile. RESULTS: T cells isolated from positive intradermal test reactions to suxamethonium showed a strict dose-dependent proliferation in response to drug-pulsed autologous antigen-presenting cells. The drug-specific CD4+ T cells were oligoclonal memory CD3+CD4+ T cells and expressed the skin homing receptors cutaneous lymphocyte antigen (CLA) and CCR4. Furthermore CD4+ suxamethonium-reactive T cell lines were IFN-gamma-positive and synthesized high levels of IFN-gamma and TNF-alpha. CONCLUSION: The study describes a delayed hypersensitivity to suxamethonium, driven by an oligoclonal T helper cell 1-skewed CD4+ memory T cell population, expressing the skin homing receptors CLA and CCR4.

Liquid chromatography/mass spectrometry analysis of exhaled leukotriene B4 in asthmatic children.

BACKGROUND: The role of leukotriene (LT) B4, a potent inflammatory mediator, in atopic asthmatic and atopic nonasthmatic children is largely unknown. The lack of a gold standard technique for measuring LTB4 in exhaled breath condensate (EBC) has hampered its quantitative assessment in this biological fluid. We sought to measure LTB4 in EBC in atopic asthmatic children and atopic nonasthmatic children. Exhaled nitric oxide (NO) was measured as an independent marker of airway inflammation. METHODS: Fifteen healthy children, 20 atopic nonasthmatic children, 25 steroid-naïve atopic asthmatic children, and 22 atopic asthmatic children receiving inhaled corticosteroids were studied. The study design was of cross-sectional type. Exhaled LTB4 concentrations were measured using liquid chromatography/mass spectrometry-mass spectrometry (LC/MS/MS) with a triple quadrupole mass spectrometer. Exhaled NO was measured by chemiluminescence with a single breath on-line method. LTB4 values were expressed as the total amount (in pg) of eicosanoid expired in the 15-minute breath test. Kruskal-Wallis test was used to compare groups. RESULTS: Compared with healthy children [87.5 (82.5-102.5) pg, median and interquartile range], exhaled LTB4 was increased in steroid-naïve atopic asthmatic [255.1 (175.0-314.7) pg, p < 0.001], but not in atopic nonasthmatic children [96.5 (87.3-102.5) pg, p = 0.59)]. Asthmatic children who were receiving inhaled corticosteroids had lower concentrations of exhaled LTB4 than steroid-naïve asthmatics [125.0 (25.0-245.0) pg vs 255.1 (175.0-314.7) pg, p < 0.01, respectively]. Exhaled NO was higher in atopic nonasthmatic children [16.2 (13.5-22.4) ppb, p < 0.05] and, to a greater extent, in atopic steroid-naïve asthmatic children [37.0 (31.7-57.6) ppb, p < 0.001] than in healthy children [8.3 (6.1-9.9) ppb]. Compared with steroid-naïve asthmatic children, exhaled NO levels were reduced in asthmatic children who were receiving inhaled corticosteroids [15.9 (11.5-31.7) ppb, p < 0.01]. CONCLUSION: In contrast to exhaled NO concentrations, exhaled LTB4 values are selectively elevated in steroid-naïve atopic asthmatic children, but not in atopic nonasthmatic children. Although placebo control studies are warranted, inhaled corticosteroids seem to reduce exhaled LTB4 in asthmatic children. LC/MS/MS analysis of exhaled LTB4 might provide a non-invasive, sensitive, and quantitative method for airway inflammation assessment in asthmatic children.

Ion trap liquid chromatography/tandem mass spectrometry analysis of leukotriene B4 in exhaled breath condensate.

The objective of this study is the measurement of leukotriene B7 (LTB4), a potent inflammatory mediator, in exhaled breath condensate by using liquid chromatography/mass spectrometry (LC/MS and LC/MS/MS). Condensation of exhaled breath is a non-invasive method to collect airway secretions. Deuterated (d4)-LTB4 was used as internal standard. The MS and MS/MS behavior of LTB4 and LTB4-d4 was studied by electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) in both positive and negative ion polarity mode. Preliminary results show that monitoring negative ions in ESI mode has the best sensitivity for both LTB4 and LTB4-d4. Therefore, negative ESI was chosen, and the [M-H]- ions at m/z 335 and 339 were selected for quantification. The lower limit of quantification for LTB4, expressed as the lowest point of the calibration curve, was 100 pg/mL. Using this technique, we measured LTB4 in exhaled breath condensate in two healthy subjects, four asthmatic patients on anti-inflammatory treatment, and four asthmatic patients who were not on anti-inflammatory drugs. Exhaled LTB4 concentrations were detected only in asthmatic patients who were not on anti-inflammatory therapy. This method is potentially useful for non-invasive assessment of airway inflammation, but the sensitivity of the technique needs to be improved.

Effects of inhaled corticosteroids on exhaled leukotrienes and prostanoids in asthmatic children.

BACKGROUND: Lipid mediators play an important pathophysiologic role in atopic asthmatic children, but their role in the airways of atopic nonasthmatic children is unknown. OBJECTIVE: We sought (1) to measure leukotriene (LT) E 4 , LTB 4 , 8-isoprostane, prostaglandin E 2 , and thromboxane B 2 concentrations in exhaled breath condensate in atopic asthmatic and atopic nonasthmatic children; (2) to measure exhaled nitric oxide (NO) as an independent marker of airway inflammation; and (3) to study the effect of inhaled corticosteroids on exhaled eicosanoids. METHODS: Twenty healthy children, 20 atopic nonasthmatic children, 30 steroid-naive atopic asthmatic children, and 25 atopic asthmatic children receiving inhaled corticosteroids were included in a cross-sectional study. An open-label study with inhaled fluticasone (100 microg twice a day for 4 weeks) was undertaken in 14 steroid-naive atopic asthmatic children. RESULTS: Compared with control subjects, exhaled LTE 4 ( P <.001), LTB 4 ( P <.001), and 8-isoprostane ( P <.001) levels were increased in both steroid-naive and steroid-treated atopic asthmatic children but not in atopic nonasthmatic children (LTE 4 , P=.14; LTB 4 , P=.23; and 8-isoprostane, P=.52). Exhaled NO levels were increased in steroid-naive atopic asthmatic children ( P <.001) and, to a lesser extent, in atopic nonasthmatic children ( P <.01). Inhaled fluticasone reduced exhaled NO (53%, P <.0001) and, to a lesser extent, LTE 4 (18%, P <.01) levels but not LTB 4 , prostaglandin E 2 , or 8-isoprostane levels in steroid-naive asthmatic children. Conclusions Exhaled LTE 4 , LTB 4 , and 8-isoprostane levels are increased in atopic asthmatic children but not in atopic nonasthmatic children. In contrast to exhaled NO, these markers seem to be relatively resistant to inhaled corticosteroids.