Mannitol dry powder challenge in comparison with exercise testing in children

Rationale Mannitol dry powder (MDP) challenge is an indirect bronchial provocation test, which is well studied in adults but not established for children. Objective We compared feasibility, validity, and clinical significance of MDP challenge with exercise testing in children in a clinical setting. Methods Children aged 6–16 years, referred to two respiratory outpatient clinics for possible asthma diagnosis, underwent standardized exercise testing followed within a week by an MDP challenge (Aridol™, Pharmaxis, Australia). Agreement between the two challenge tests using Cohen's kappa and receiving operating characteristic (ROC) curves was compared. Results One hundred eleven children performed both challenge tests. Twelve children were excluded due to exhaustion or insufficient cooperation (11 at the exercise test, 1 at the MDP challenge), leaving 99 children (mean ± SD age 11.5 ± 2.7 years) for analysis. MDP tests were well accepted, with minor side effects and a shorter duration than exercise tests. The MDP challenge was positive in 29 children (29%), the exercise test in 21 (21%). Both tests were concordant in 83 children (84%), with moderate agreement (κ = 0.58, 95% CI 0.39–0.76). Positive and negative predictive values of the MDP challenge for exercise-induced bronchoconstriction were 68% and 89%. The overall ability of MDP challenge to separate children with or without positive exercise tests was good (area under the ROC curve 0.83). Conclusions MDP challenge test is feasible in children and is a suitable alternative for bronchial challenge testing in childhood. Pediatr. Pulmonol. 2011; 46:842–848. © 2011 Wiley-Liss, Inc.

[Analgesia for pediatric patients. Standards and special aspects]

In this paper we describe the assessment and medical treatment of pain in children according to the concept of the Centre of Pediatrics and Adolescent Medicine at the university of Freiburg, Germany. Opiate therapy in children as well as novel data about the association of paracetamol (acetaminophen) and wheezing/asthma bronchiale in children are discussed. Special aspects of analgesia for painful procedures and a nitrous oxide/oxygen mixture which has been recently introduced in Germany are described. The second part of the paper presents results of our prospective study about continuous infusion of fentanyl and midazolam in a fixed combination in 19 critically ill patients with a median age of 46 months, 40% of these patients had an ARDS. The mortality rate was 21%. A median dose of fentanyl of 3.9 microg/kg/h (midazolam 0.26 mg/kg/h) was infused. The fentanyl serum level (median 4.2 ng/ml, range 1.7-17.8 ng/ml) correlated significantly with the administered dose while the midazolam serum levels (median 911 ng/ml, range 234-4 651 ng/ml) correlated neither with the administered dose nor with any of the analysed parameters. Conclusion: A standard protocol for the assessment and treatment of pain should be established in every pediatric hospital. The data about the association of asthma bronchiale and paracetamol cannot be interpreted conclusively, but show that even for well known substances clinical trials may lead to new awareness. The study data about continuous infusion of fentanyl and midazolam show a good correlation of the fentanyl application to serum levels, while midazolam appears to be not the optimal substance for continuous sedation in this setting.

The chitinase-like protein YKL-40 modulates cystic fibrosis lung disease

The chitinase-like protein YKL-40 was found to be increased in patients with severe asthma and chronic obstructive pulmonary disease (COPD), two disease conditions featuring neutrophilic infiltrates. Based on these studies and a previous report indicating that neutrophils secrete YKL-40, we hypothesized that YKL-40 plays a key role in cystic fibrosis (CF) lung disease, a prototypic neutrophilic disease. The aim of this study was (i) to analyze YKL-40 levels in human and murine CF lung disease and (ii) to investigate whether YKL-40 single-nucleotide polymorphisms (SNPs) modulate CF lung disease severity. YKL-40 protein levels were quantified in serum and sputum supernatants from CF patients and control individuals. Levels of the murine homologue BRP-39 were analyzed in airway fluids from CF-like βENaC-Tg mice. YKL-40SNPs were analyzed in CF patients. YKL-40 levels were increased in sputum supernatants and in serum from CF patients compared to healthy control individuals. Within CF patients, YKL-40 levels were higher in sputum than in serum. BRP-39 levels were increased in airways fluids from βENaC-Tg mice compared to wild-type littermates. In both CF patients and βENaC-Tg mice, YKL-40/BRP-39 airway levels correlated with the severity of pulmonary obstruction. Two YKL-40 SNPs (rs871799 and rs880633) were found to modulate age-adjusted lung function in CF patients. YKL-40/BRP-39 levelsare increased in human and murine CF airway fluids, correlate with pulmonary function and modulate CF lung disease severity genetically. These findings suggest YKL-40 as a potential biomarker in CF lung disease.

Fluctuation phenotyping based on daily fraction of exhaled nitric oxide values in asthmatic children

Fraction of exhaled nitric oxide (Feno), a marker of airway inflammation, has been proposed to be useful for asthma management, but conclusions are inconsistent. This might be due to the failure of mean statistics to characterize individual variability in Feno values, which is possibly a better indicator of asthma control than single measurements.

The GABRIEL Advanced Surveys: study design, participation and evaluation of bias

Exposure to farming environments has been shown to protect substantially against asthma and atopic disease across Europe and in other parts of the world. The GABRIEL Advanced Surveys (GABRIELA) were conducted to determine factors in farming environments which are fundamental to protecting against asthma and atopic disease. The GABRIEL Advanced Surveys have a multi-phase stratified design. In a first-screening phase, a comprehensive population-based survey was conducted to assess the prevalence of exposure to farming environments and of asthma and atopic diseases (n = 103,219). The second phase was designed to ascertain detailed exposure to farming environments and to collect biomaterial and environmental samples in a stratified random sample of phase 1 participants (n = 15,255). A third phase was carried out in a further stratified sample only in Bavaria, southern Germany, aiming at in-depth respiratory disease and exposure assessment including extensive environmental sampling (n = 895). Participation rates in phase 1 were around 60% but only about half of the participating study population consented to further study modules in phase 2. We found that consenting behaviour was related to familial allergies, high parental education, wheeze, doctor diagnosed asthma and rhinoconjunctivitis, and to a lesser extent to exposure to farming environments. The association of exposure to farm environments with asthma or rhinoconjunctivitis was not biased by participation or consenting behaviour. The GABRIEL Advanced Surveys are one of the largest studies to shed light on the protective 'farm effect' on asthma and atopic disease. Bias with regard to the main study question was able to be ruled out by representativeness and high participation rates in phases 2 and 3. The GABRIEL Advanced Surveys have created extensive collections of questionnaire data, biomaterial and environmental samples promising new insights into this area of research.

The interleukin 4 receptor gene and its role in recurrent airway obstruction in Swiss Warmblood horses

Recurrent airway obstruction (RAO) in horses is the result of an interaction of genetic and environmental factors and shares many characteristics with human asthma. Many studies have suggested that the interleukin-4 receptor gene (IL4R) is associated with this disease, and a QTL region on chromosome 13 containing IL4R was previously detected in one of the two Swiss Warmblood families. We sequenced the entire IL4R gene in this family and detected 93 variants including five non-synonymous protein-coding variants. The allele distribution at these SNPs supported the previously detected QTL signal. Subsequently, we investigated IL4R mRNA expression in bronchoalveolar lavage fluid cells. During exacerbation, IL4R expression was increased in RAO-affected offspring in the implicated family, but not in the other family. These findings support that IL4R plays a role in some cases of RAO.

Molecular cloning and characterization of equine thymic stromal lymphopoietin

Thymic stromal lymphopoietin (TSLP) is a novel cytokine that plays a central role in T helper 2 (Th2) cell differentiation and allergic inflammation. It is predominantly expressed by epithelial cells, and its expression is increased in patients with atopic dermatitis and asthma. Mice overexpressing TSLP in the skin develop allergic dermatitis and mice overexpressing TSLP in lungs develop asthma-like disease. However, it is not known whether TSLP plays an important role in equine allergies. Therefore, we cloned and sequenced the complete translated region of equine TSLP gene and measured its expression in various tissues. The equine TSLP gene is organized in 4 exons and encodes a protein of 143 amino acids, which has 62% amino acid identity with human TSLP.

Novel insights into mechanisms of food allergy and allergic airway inflammation using experimental mouse models

Over the last decades, considerable efforts have been undertaken in the development of animal models mimicking the pathogenesis of allergic diseases occurring in humans. The mouse has rapidly emerged as the animal model of choice, due to considerations of handling and costs and, importantly, due to the availability of a large and increasing arsenal of genetically modified mouse strains and molecular tools facilitating the analysis of complex disease models. Here, we review latest developments in allergy research that have arisen from in vivo experimentation in the mouse, with a focus on models of food allergy and allergic asthma, which constitute major health problems with increasing incidence in industrialized countries. We highlight recent novel findings and controversies in the field, most of which were obtained through the use of gene-deficient or germ-free mice, and discuss new potential therapeutic approaches that have emerged from animal studies and that aim at attenuating allergic reactions in human patients.

Pediatric and adult eosinophilic esophagitis: similarities and differences

Early in the 1990s, several case series described adults suffering from dysphagia and children with refractory reflux symptoms, both accompanied by an eosinophil-predominant infiltration, thereby conclusively distinguishing it from gastroesophageal reflux disease. Eosinophilic esophagitis (EoE) was recognized as its own entity in the adult and in the pediatric literature. In the last decade, evidence has accumulated that EoE represents a T-helper (Th)2-type inflammatory disease. Remodeling of the esophagus is a hallmark of EoE, leading to esophageal dysfunction and bolus impaction. Familial occurrence and disease association with single-nucleotide polymorphisms underscore the influence of genetics in this disease. Eosinophilic esophagitis may affect individuals at any age, although the clinical presentation is highly age dependent. There is a significant allergic bias in the EoE population, with the majority of patients having concurrent allergic rhinitis, asthma, eczema, and/or a history of atopy. One noteworthy difference is that in children, EoE seems to be primarily a food antigen-driven disease, whereas in adults, mainly aeroallergen sensitization has been observed. Treatment modalities for EoE include the 3Ds: drugs, diet, and dilation. The crucial question of whether adult and pediatric EoE are different phenotypes of one single entity or whether we are confronted with two different diseases is still open. Here, we review similarities and differences between EoE in adults and children.

Increased parasite resistance and recurrent airway obstruction in horses of a high-prevalence family

BACKGROUND: Equine recurrent airway obstruction (RAO) shares many characteristics with human asthma. In humans, an inverse relationship between susceptibility to asthma and resistance to parasites is suspected. HYPOTHESIS/OBJECTIVES: Members of a high-incidence RAO half-sibling family (F) shed fewer strongylid eggs compared with RAO-unaffected pasture mates (PM) and that RAO-affected horses shed fewer eggs than RAO-unaffected half-siblings. ANIMALS: Seventy-three F and 73 unrelated, age matched PM. METHODS: Cases and controls kept under the same management and deworming regime were examined. Each individual was classified as RAO affected or RAO unaffected and fecal samples were collected before and 1-3 weeks and 3 months after deworming. Samples were analyzed by combined sedimentation-flotation and modified McMaster methods and classified into 3 categories of 0 eggs per gram of feces (EpG), 1-100 EpG, and > 100 EpG, respectively. RESULTS: PM compared with RAO-affected F had a 16.7 (95% confidence interval [CI]: 2.0-136.3) times higher risk for shedding > 100 EpG compared with 0 EpG and a 5.3 (95% CI: 1.0-27.4) times higher risk for shedding > 100 EpG compared with 0 EpG. There was no significant effect when RAO-unaffected F were compared with their PM. RAO-unaffected compared with RAO-affected offspring had a 5.8 (95% CI: 0.0-1.0) times higher risk for shedding 1-100 EpG. Age, sex, breed, and sharing pastures with other species had no significant confounding effects. CONCLUSION AND CLINICAL IMPORTANCE: RAO is associated with resistance against strongylid parasites in a high-prevalence family.

Accelerated disassembly of IgE-receptor complexes by a disruptive macromolecular inhibitor

IgE antibodies bind the high-affinity IgE Fc receptor (FcεRI), found primarily on mast cells and basophils, and trigger inflammatory cascades of the allergic response. Inhibitors of IgE-FcεRI binding have been identified and an anti-IgE therapeutic antibody (omalizumab) is used to treat severe allergic asthma. However, preformed IgE-FcεRI complexes that prime cells before allergen exposure dissociate extremely slowly and cannot be disrupted by strictly competitive inhibitors. IgE-Fc conformational flexibility indicated that inhibition could be mediated by allosteric or other non-classical mechanisms. Here we demonstrate that an engineered protein inhibitor, DARPin E2_79 (refs 9, 10, 11), acts through a non-classical inhibition mechanism, not only blocking IgE-FcεRI interactions, but actively stimulating the dissociation of preformed ligand-receptor complexes. The structure of the E2_79-IgE-Fc(3-4) complex predicts the presence of two non-equivalent E2_79 sites in the asymmetric IgE-FcεRI complex, with site 1 distant from the receptor and site 2 exhibiting partial steric overlap. Although the structure is indicative of an allosteric inhibition mechanism, mutational studies and quantitative kinetic modelling indicate that E2_79 acts through a facilitated dissociation mechanism at site 2 alone. These results demonstrate that high-affinity IgE-FcεRI complexes can be actively dissociated to block the allergic response and suggest that protein-protein complexes may be more generally amenable to active disruption by macromolecular inhibitors.

An integrated nano-scale approach to profile miRNAs in limited clinical samples

Profiling miRNA expression in cells that directly contribute to human disease pathogenesis is likely to aid the discovery of novel drug targets and biomarkers. However, tissue heterogeneity and the limited amount of human diseased tissue available for research purposes present fundamental difficulties that often constrain the scope and potential of such studies. We established a flow cytometry-based method for isolating pure populations of pathogenic T cells from bronchial biopsy samples of asthma patients, and optimized a high-throughput nano-scale qRT-PCR method capable of accurately measuring 96 miRNAs in as little as 100 cells. Comparison of circulating and airway T cells from healthy and asthmatic subjects revealed asthma-associated and tissue-specific miRNA expression patterns. These results establish the feasibility and utility of investigating miRNA expression in small populations of cells involved in asthma pathogenesis, and set a precedent for application of our nano-scale approach in other human diseases. The microarray data from this study (Figure 7) has been submitted to the NCBI Gene Expression Omnibus (GEO; http://ncbi.nlm.nih.gov/geo) under accession no. GSE31030.

Guidelines for treatment of atopic eczema (atopic dermatitis) Part II

The existing evidence for treatment of atopic eczema (atopic dermatitis, AE) is evaluated using the national standard Appraisal of Guidelines Research and Evaluation. The consensus process consisted of a nominal group process and a DELPHI procedure. Management of AE must consider the individual symptomatic variability of the disease. Basic therapy is focused on hydrating topical treatment, and avoidance of specific and unspecific provocation factors. Anti-inflammatory treatment based on topical glucocorticosteroids and topical calcineurin inhibitors (TCI) is used for exacerbation management and more recently for proactive therapy in selected cases. Topical corticosteroids remain the mainstay of therapy, but the TCI tacrolimus and pimecrolimus are preferred in certain locations. Systemic immune-suppressive treatment is an option for severe refractory cases. Microbial colonization and superinfection may induce disease exacerbation and can justify additional antimicrobial treatment. Adjuvant therapy includes UV irradiation preferably with UVA1 wavelength or UVB 311 nm. Dietary recommendations should be specific and given only in diagnosed individual food allergy. Allergen-specific immunotherapy to aeroallergens may be useful in selected cases. Stress-induced exacerbations may make psychosomatic counselling recommendable. 'Eczema school' educational programs have been proven to be helpful. Pruritus is targeted with the majority of the recommended therapies, but some patients need additional antipruritic therapies.

Guidelines for treatment of atopic eczema (atopic dermatitis) part I

The existing evidence for treatment of atopic eczema (atopic dermatitis, AE) is evaluated using the national standard Appraisal of Guidelines Research and Evaluation. The consensus process consisted of a nominal group process and a DELPHI procedure. Management of AE must consider the individual symptomatic variability of the disease. Basic therapy is focused on hydrating topical treatment, and avoidance of specific and unspecific provocation factors. Anti-inflammatory treatment based on topical glucocorticosteroids and topical calcineurin inhibitors (TCI) is used for exacerbation management and more recently for proactive therapy in selected cases. Topical corticosteroids remain the mainstay of therapy, but the TCI tacrolimus and pimecrolimus are preferred in certain locations. Systemic immune-suppressive treatment is an option for severe refractory cases. Microbial colonization and superinfection may induce disease exacerbation and can justify additional antimicrobial treatment. Adjuvant therapy includes UV irradiation preferably with UVA1 wavelength or UVB 311 nm. Dietary recommendations should be specific and given only in diagnosed individual food allergy. Allergen-specific immunotherapy to aeroallergens may be useful in selected cases. Stress-induced exacerbations may make psychosomatic counselling recommendable. 'Eczema school' educational programs have been proven to be helpful. Pruritus is targeted with the majority of the recommended therapies, but some patients need additional antipruritic therapies.

Atemwegserkrankungen und Allergien

Aufgrund ihrer großen Oberfläche und des dort stattfindenden Gasaustauschs ist die Lunge den zahlreichen Luftschadstoffen unmittelbar ausgesetzt. Besonders empfindlich hierfür ist die noch wachsende Lunge. Atemwegserkrankungen und Allergien können dann die Folge sein. Sowohl in Mitteleuropa wie auch in den sog. Entwicklungsländern sind Atemwegserkrankungen eine bedeutende Ursache der Krankheitslast (Burden of Disease). Betroffen sind vorwiegend Kinder und ältere Menschen. In Entwicklungsländern tragen Lungenentzündung und Tuberkulose signifikant zur Gesamtmortalität bei, in den westlichen Industrienationen sind chronische Atemwegserkrankungen wie COPD und Asthma für einen erheblichen Teil der Gesamtmorbidität verantwortlich. In diesem Abschnitt betrachten wir die Entwicklung der Lungenfunktion im Laufe des Lebens, die unterschiedliche Vulnerabilität der Lunge gegenüber Umwelteinflüssen in den verschiedenen Entwicklungsstadien sowie die globale Krankheitslast als Folge von respiratorischen Erkrankungen. Anschließend beschreiben wir das Asthma und die COPD hinsichtlich ihrer Risikofaktoren und erörtern, mit welchen präventiven Maßnahmen diese Erkrankungen zu verhindern wären. Schweizerische Lernziele: CPH 40