Assessment of neuro-pulmonary crosstalk in asthmatic mice: effects of DiNP exposure on cellular respiration, mitochondrial oxidative status and apoptotic signaling.

Human health is becoming concerned about exposure to endocrine disrupting chemicals (EDCs) emanating from plastic, such as phthalates, which are industrially employed as plasticizers in the manufacturing of plastic products. Due to some toxicity concerns, di(2-ethylhexyl) phthalate (DEHP) was replaced by diisononyl phthalate (DiNP). Recent data, however, highlights the potential of DiNP to interfere with the endocrine system and influence allergic responses. Asthma affects brain function through hypoxia, systemic inflammation, oxidative stress, and sleep disturbances and its effective management is crucial for maintaining respiratory and brain health. Therefore, in DiNP-induced asthmatic mice, this study investigated possible crosstalk between the lungs and the brain inducing perturbations in neural mitochondrial antioxidant status, inflammation biomarkers, energy metabolizing enzymes, and apoptotic indicators. To achieve this, twelve (n = 12, 20-30 g) male BALB/c mice were divided into two (2) experimental groups, each with five (6) mice. Mice in group II were subjected to 50 mg/kg body weight (BW) DiNP (Intraperitoneal and intranasal), while group I served as the control group for 24 days. The effects of DiNP on neural energy metabolizing enzymes (Hexokinase, Aldolase, NADase, Lactate dehydrogenase, Complex I, II, II & IV), biomarkers of inflammation (Nitric oxide, Myeloperoxidase), oxidative stress (malondialdehyde), antioxidants (catalase, glutathione-S-transferase, and reduced glutathione), oncogenic and apoptotic factors (p53, K-ras, Bcl, etc.), and brain histopathology were investigated. DiNP-induced asthmatic mice have significantly (p < 0.05) altered neural energy metabolizing capacities due to disruption of activities of enzymes of glycolytic and oxidative phosphorylation. Other responses include significant inflammation, oxidative distress, decreased antioxidant status, altered oncogenic-apoptotic factors level and neural degeneration (as shown in hematoxylin and eosin-stained brain sections) relative to control. Current findings suggest that neural histoarchitecture, energy metabolizing potentials, inflammation, oncogenic and apoptotic factors, and mitochondrial antioxidant status may be impaired and altered in DiNP-induced asthmatic mice suggesting a pivotal crosstalk between the two intricate organs (lungs and brain).

Characterization and applicability of a novel physiologically relevant 3D-tetraculture bronchial model for in vitro assessment of respiratory sensitization.

Chemical Respiratory Allergy (CRA) is triggered after exposure to Low Molecular Weight (LMW) sensitizers and manifests clinically as asthma and rhinitis. From a risk/toxicity assessment point of view, there are few methods, none of them validated, for evaluating the respiratory sensitization potential of chemicals once the in vivo-based models usually employed for inhalation toxicity addressment do not comprise allergenicity endpoints specifically. Based on that, we developed, characterized, and evaluated the applicability of a 3D-tetraculture airway model reconstructed with bronchial epithelial, fibroblasts, endothelial and monocytic cell lines. Moreover, we exposed the tissue to maleic anhydride (MA) aerosols to challenge the model and subsequently assessed inflammatory and functional aspects of the tissue. The reconstructed tissue presented phenotypic biomarkers compatible with human bronchial epithelium, and MA aerosol exposure triggered an increased IL-8 and IL-6 production, reactive oxygen species (ROS) formation, and apoptosis of epithelial cells. Besides, augmented IL-8 production by monocytic cells was also found, correlating with dendritic cell activation within the co-culture model after MA exposure. Our results demonstrated that the 3D-tetraculture bronchial model presents hallmarks related to human airways' structure and function. Additionally, exposure to a respiratory sensitizer induced inflammatory and functional alterations in the reconstructed tissue, rendering it a valuable tool for exploring the mechanistic framework of chemically induced respiratory sensitization.

Multimorbidity in asthma, association with allergy, inflammatory markers and symptom burden, results from the Swedish GA2 LEN study.

BACKGROUND: Asthma is common worldwide and a large part of subjects with asthma have concomitant allergic multimorbidity in the form of rhinitis and/or eczema. OBJECTIVE: The aim of this study is to investigate whether the presence of allergic multimorbidity in asthma relates to allergic sensitization, allergic and respiratory symptoms, quality of life, inflammatory markers, lung function, use of medication and background factors. METHODS: A total of 437 asthmatics from the (GA2 LEN) cross-sectional survey in Sweden were grouped depending on the presence of rhinitis and/or eczema. The impact of allergic multimorbidity was assessed in terms of allergic sensitization, allergic and respiratory symptoms, quality of life, type-2 inflammatory markers (exhaled nitric oxide, eosinophil activation markers, periostin), lung function, use of medication and background factors. RESULTS: Subjects with asthma, rhinitis and eczema were more likely to be sensitized to seasonal allergens (67% vs 32%, P < .001), food allergens (54% vs 18%, P < .001) and to have a higher degree of sensitization than subjects with only asthma (23% vs 10%, P < .001). Subjects with allergic multimorbidity more often had allergic reactions to food (28% vs 10%, P = .002), more respiratory symptoms and anxiety/depression (40% vs, 14%, P < .001) than subjects with only asthma, despite having similar levels of type 2 inflammatory markers. Individuals with allergic multimorbidity were more likely to be diagnosed with asthma before the age of 12 (48% vs 27%, P = .016) and to have maternal heredity for allergy (53% vs 33%, P = .011) than subjects with only asthma. CONCLUSION AND CLINICAL RELEVANCE: Asthmatics with allergic multimorbidity are more likely to be sensitized to seasonal aeroallergens, food allergens and they have a higher degree of sensitization compared with those with only asthma. Allergic multimorbidity is associated with respiratory and allergy symptoms, anxiety and/or depression.

Assessment of adherence to corticosteroids in asthma by drug monitoring or fractional exhaled nitric oxide: A literature review.

BACKGROUND: Although the efficacy of corticosteroid treatment in controlling asthma is widely accepted, its effectiveness is undermined by poor adherence. However, the optimal method for measuring adherence to asthma therapy remains unclear. OBJECTIVE: To perform a review of the literature reporting biological, objective methods for assessing adherence to inhaled or oral corticosteroids in asthma; we included studies reporting direct measurement of exogenous corticosteroids in blood, or the effect of adherence on exhaled nitric oxide. DESIGN: We searched three databases MEDLINE (using both PubMed and Ovid), the Cumulative Index of Nursing and Allied Health Literature (CINAHL) and Web of Science for articles published between January 1975 and July 2020. Quality of the studies was assessed using the National Institute of Health checklist. RESULTS: From 2850 screened articles, 26 fulfilled the inclusion criteria. Measurement of blood prednisolone with or without cortisol was used in eight studies as a measure of oral corticosteroid adherence, and fractional exhaled nitric oxide (FeNO) in 17 studies for inhaled corticosteroid adherence. Inhaled corticosteroids were measured directly in the blood in one study. By direct measurement of drug levels in the blood, adherence rates to oral corticosteroids ranged from 47% to 92%, although the performance and timing of the test were often not known, making interpretation of findings and serum prednisolone concentrations difficult. FeNO is generally lower in adherent than non-adherent patients, but no absolute cut-off can be proposed based on the available data. However, a fall in FeNO following supervised inhaled corticosteroid dosing could indicate previous poor adherence. CONCLUSIONS AND CLINICAL RELEVANCE: Despite prednisolone and cortisol levels commonly being used as adherence markers in clinical practice, further work is required to assess the influence of the dose and timing on blood levels. The promising findings of FeNO suppression testing should be explored in further prospective studies.

Assessment of Lung Eosinophils In Situ Using Immunohistological Staining.

Eosinophils are rare white blood cells that are recruited from circulation to accumulate in the lung in mouse models of allergic respiratory inflammation. In hematoxylin-eosin (HE) stained lungs, eosinophils may be difficult to detect despite their bright eosin staining in the secondary granules. For this reason, antibody-mediated detection of eosinophils is preferable for specific and clearer identification of these cells. Moreover, eosinophils may degranulate, releasing their granule proteins into surrounding tissue, and remnants of cytolysed cells cannot be detected by HE staining. The methods here demonstrate the use of eosinophil-specific anti-mouse antibodies to detect eosinophil granule proteins in formalin-fixed cells both in situ in paraffin-embedded lungs, as well as in cytospin preparations from the lung. These antibody staining techniques enable either colorimetric or fluorescence imaging of eosinophils or their granule proteins with the potential for additional antibodies to be added for detection of multiple molecules.

Impact of different fixed flow sampling protocols on flow-independent exhaled nitric oxide parameter estimates using the Bayesian dynamic two-compartment model.

Exhaled nitric oxide (FeNO) is an established respiratory biomarker with clinical applications in the diagnosis and management of asthma. Because FeNO depends strongly on the flow (exhalation) rate, early protocols specified that measurements should be taken when subjects exhaled at a fixed rate of 50 ml/s. Subsequently, multiple flow (or "extended") protocols were introduced which measure FeNO across a range of fixed flow rates, allowing estimation of parameters including Caw NO and CA NO which partition the physiological sources of NO into proximal airway wall tissue and distal alveolar regions (respectively). A recently developed dynamic model of FeNO uses flow-concentration data from the entire exhalation maneuver rather than plateau means, permitting estimation of Caw NO and CA NO from a wide variety of protocols. In this paper, we use a simulation study to compare Caw NO and CA NO estimation from a variety of fixed flow protocols, including: single maneuvers (30, 50,100, or 300 ml/s) and three established multiple maneuver protocols. We quantify the improved precision with multiple maneuvers and the importance of low flow maneuvers in estimating Caw NO. We conclude by applying the dynamic model to FeNO data from 100 participants of the Southern California Children's Health Study, establishing the feasibility of using the dynamic method to reanalyze archived online FeNO data and extract new information on Caw NO and CA NO in situations where these estimates would have been impossible to obtain using traditional steady-state two compartment model estimation methods.

Reducing Asthma Attacks in Children using Exhaled Nitric Oxide as a biomarker to inform treatment strategy: a randomised trial (RAACENO).

BACKGROUND: Childhood asthma is a common condition. Currently there is no validated objective test which can be used to guide asthma treatment in children. This study tests the hypothesis that the addition of fractional exhaled nitric oxide (FENO) monitoring in addition to standard care reduces the number of exacerbations (or attacks) in children with asthma. METHODS: This is a multi-centre, randomised controlled study. Children will be included of age 6-16 years who have a diagnosis of asthma, currently use inhaled corticosteroids (ICSs) and have had an exacerbation in the previous 12 months. Exclusion criteria include being unable to provide FENO measurement at baseline assessment, having another chronic respiratory condition and being currently treated with maintenance oral steroids. Participants will be recruited in both primary and secondary care settings and will be randomised to either receive asthma treatment guided by FENO plus symptoms (FENO group) or asthma treatment guided by symptoms only (standard care group). Within the FENO group, different treatment decisions will be made dependent on changes in FENO. Participants will attend assessments 3, 6, 9 and 12 months post randomisation. The primary outcome is asthma exacerbation requiring prescription and/or use of an oral corticosteroid over 12 months as recorded by the participant/parent or in general practitioner records. Secondary outcomes include time to first attack, number of attacks, asthma control score and quality of life. Adherence to ICS treatment is objectively measured by an electronic logging device. Participants are invited to participate in a "phenotyping" assessment where skin prick reactivity and bronchodilator response are determined and a saliva sample is collected for DNA extraction. Qualitative interviews will be held with participants and research nurses. A health economic evaluation will take place. DISCUSSION: This study will evaluate whether FENO can provide an objective index to guide and stratify asthma treatment in children. TRIAL REGISTRATION: ISRCTN, ISRCTN67875351. Registered on 12 April 2017. Prospectively registered.

Validation of Asthma Control Assessment Among Urban Adolescents Using the Asthma Control and Communication Instrument.

BACKGROUND: The National Institutes of Health guidelines recommend questionnaires to assess asthma control, but there are few self-reported asthma morbidity surveys validated among urban, African American, Hispanic, and/or poor adolescents. The Asthma Control and Communication Instrument (ACCI) is a 12-item self-reported questionnaire previously validated among a diverse adult population, but not among adolescents. OBJECTIVE: To assess the ability of the ACCI to accurately describe asthma control in an urban adolescent population. METHODS: Between November 13, 2014, and March 2, 2017, we collected information using the ACCI, the Asthma Control Test, the Pediatric Asthma Quality of Life Questionnaire, and lung function among adolescents enrolled in a school-based asthma intervention study. The ACCI measure of asthma control was validated by evaluating accuracy (on the basis of receiver operating characteristic curve), internal reliability, and concurrent and discriminative validity. RESULTS: We collected information on 280 adolescents (mean age, 13.4 years; 56% males; and 51% African American). ACCI control showed good internal reliability and strong concurrent and discriminative validity with the Asthma Control Test and the Pediatric Asthma Quality of Life Questionnaire. The accuracy of the ACCI in classifying adolescents with uncontrolled asthma was good (area under the curve, 0.83; 95% CI, 0.79-0.88). CONCLUSION: The ACCI, a clinical tool developed to assist communication about asthma control, has demonstrated strong construct validity as a self-reported questionnaire within an urban, African American, and Hispanic sample of adolescents. It has the potential to assist in the assessment of asthma control in urban, minority, and/or poor adolescents.

Asthma alleviates obesity in males through regulating metabolism and energy expenditure.

Many epidemiological studies suggested a correlation between obesity and asthma. However, little is known about the molecular details explaining this correlation. Here, we show that asthma decreased body weight of asthmatic male mice fed with high fat diet via increasing energy expenditure and insulin sensitivity. The increase of energy expenditure was mainly due to upregulation of pAMPK and Sirt1. The activation of AMPK/Sirt1/PGC1α signaling promoted the expression of the thermogenic genes like ucp1, PRDM16, cidea, Elovl3, PPARα, which occurred in brown adipocyte tissue and subcutaneous white adipose tissue. Besides, by activating IL33/ILC2/AAMac pathway in subcutaneous white adipose tissue, asthma promoted subcutaneous white adipose tissue into beige fat. In addition, insulin sensitivity was improved in the asthmatic male mice by decreasing the expression of G6Pase in the liver, which was recapitulated in HepG2. In human, we found that Body Mass Index (BMI) and waist circumference were significantly lower in males suffering asthma compared with the control in the National Health and Nutrition Examination Survey (NHANES) cohort. These data together suggest asthma in males decreases obesity by improving the metabolism function of brown and subcutaneous adipose tissue, and decreasing insulin resistant in the liver.

Cost impact of monitoring exhaled nitric oxide in asthma management.

BACKGROUND: Asthma guidelines recommend periodic assessment of impairment and risk factors to prevent exacerbations, which can lead to hospitalization and increased health care utilization and cost. According to recent meta-analysis data, fractional exhaled nitric oxide (FeNO) monitoring is associated with a 40-50% reduction in the risk of exacerbations. OBJECTIVE: Cost modeling of these data indicates the potential for significant cost savings with FeNO use. Therefore, we attempted to verify this potential for cost savings within a real-world data base of Medicare beneficiaries. METHODS: This retrospective observational study investigated asthma-related claims from a Medicare data base. Beneficiaries were included who had 2 years of records after an asthma-related inpatient hospitalization (IP) or emergency department (ED) claim. A case-crossover analysis was completed of asthma-related IP or ED events before and after FeNO use during the 2-year study period. RESULTS: Of the 5911 asthma beneficiaries who met the inclusion criteria within the data base, 101 had an FeNO test during the 2-year study period. During the period before FeNO use, 98 of 101 (97%) beneficiaries had an asthma-related IP or ED event compared with 46 of 101 (46%) during the FeNO period. Asthma-related IP or ED claims and charges per beneficiary per day during the period before FeNO were 0.004 and $16.21 compared with 0.002 and $6.46 during the FeNO period (p = 0.0433 and p = 0.0133, respectively). CONCLUSION: FeNO monitoring in beneficiaries with a history of exacerbations was associated with a substantial reduction in asthma-related IP and ED claims and charges. These data supported cost modeling estimates and demonstrated that FeNO use in asthma management was associated with significant cost savings.

A Review of the Utility and Cost Effectiveness of Monitoring Fractional Exhaled Nitric Oxide (FeNO) in Asthma Management.

Asthma is a common chronic respiratory disease affecting nearly 8% of the U.S. POPULATION: It results in substantially higher direct and indirect costs as well as an increased mortality risk and poorer quality of life, particularly among patients with difficult-to-control asthma. While several physiologic tests, including spirometry, are typically used to diagnose and characterize asthma, they do not provide the sensitivity and specificity required to accurately reflect the underlying heterogeneous inflammatory pathways. Fractional exhaled nitric oxide (FeNO) is a validated, noninvasive biomarker for T2-driven (i.e., allergic) airway inflammation that correlates with sputum eosinophils at or greater than 3% across various asthma phenotypes. Its use as a biomarker in asthma is well supported by numerous peer-reviewed articles and guidelines. There is also evidence that its use in clinical settings for patients with uncontrolled asthma is cost effective, given its ability to improve the accurate diagnosis of asthma, monitor treatment response, optimize inhaled corticosteroid dosing, and identify patient nonadherence. It may also have a role in identifying patients who are possible candidates for treatment with biologics.

Cost-Effectiveness Analysis of Monitoring Fractional Exhaled Nitric Oxide (FeNO) in the Management of Asthma.

PURPOSE: Current asthma guidelines combine treatment, follow-up, and reevaluation to manage asthma control, reduce impairment, and decrease risk of morbidity in patients. Clinical use of biomarkers, such as fractional exhaled nitric oxide (FeNO), along with standard management can provide clinicians with improved ability to recognize airway inflammation, optimize drug therapy, and potentially increase asthma control. Our objective is to examine the impact of FeNO monitoring on the cost effectiveness of asthma management compared with management without FeNO. Sensitivity analyses further examine the impact of FeNO monitoring on patients with varying levels of severity and exacerbations. DESIGN AND METHODS: A decision-tree analysis of estimated outcomes and costs associated with annual management of asthma was utilized to simulate asthma management and treatment cost scenarios, comparing estimated 12-month costs and outcomes using the following treatment alternatives: (1) current standard of care (SOC) or (2) FeNO utilized in conjunction with the current SOC. Costs were estimated from the perspective of the health care payer; cost effectiveness was estimated as cost per quality-adjusted life year (QALY). RESULTS: FeNO in conjunction with SOC guidelines has decreased expected per-patient annual expenditure ($2,228) and increased expected per-patient annual QALYs (0.844) compared with SOC alone ($2,637 and 0.767). FeNO monitoring with SOC resulted in decreased annual costs and increased annual QALYs compared with SOC alone, and this difference was consistent through all one-way sensitivity analyses. CONCLUSION: Our analysis revealed that FeNO monitoring to guide asthma management is cost effective and could result in increased QALYs and decreased health care costs associated with asthma management.

U-BIOPRED: evaluation of the value of a public-private partnership to industry.

Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED) was initiated in the first year of the Innovative Medicines Initiative (IMI). It was an ambitious plan to tackle the understanding of asthma through an integration of clinical and multi-'omics approaches that necessitated the bringing together of industry, academic, and patient representatives because it was too large to be managed by any one of the partners in isolation. It was a novel experience for all concerned. In this review, we describe the main features of the U-BIOPRED experience from the industry perspective. We list some of the key advantages and learnings from the perspective of the authors, and also improvements that we feel could be made in future projects.

Biomarkers for severe allergic asthma in children: could they be useful to guide disease control and use of omalizumab?

INTRODUCTION: Although symptom controls in asthmatic children can be achieved through compliant use of conventional medication, some children have uncontrolled severe persistent asthma, especially if they are allergic. For these children, omalizumab (approved by the EMA and FDA in children aged > 6 years) could be a therapeutic option. However, response to omalizumab varies from one child to another. Predictive biomarkers of omalizumab effectiveness could be useful to monitor response to treatment. Area covered: The authors searched in the PubMed database for publications related to the use of biomarkers in allergic asthma. Supported by their own experience in phenotyping asthma in children, they analyzed whether these biomarkers could be useful in assessing response to omalizumab. Expert commentary: Th2 inflammation in children with allergic asthma can be assessed by measuring several biomarkers (blood eosinophil, serum ECP or periostin, FeNO). While a single measurement may be insufficient, a combination of biomarkers assessments may improve the follow-up of children treated by omalizumab.

Assessment of hair cortisol as a potential biomarker for possible adrenal suppression due to inhaled corticosteroid use in children with asthma: A retrospective observational study.

BACKGROUND: Inhaled corticosteroids (ICS) are the recommended long-term control therapy for asthma in children. However, concern exists regarding potential adrenal suppression with chronic ICS use. Our pilot study reported that hair cortisol in children was 50% lower during ICS therapy than prior to therapy, suggestive of adrenal suppression. OBJECTIVE: To evaluate hair cortisol concentration (HCC) as a potential biomarker for possible adrenal suppression from ICS use in children with asthma. METHODS: A retrospective observational study was performed at asthma clinics in Vancouver, Winnipeg, and Toronto, Canada. Children (n = 586) were recruited from July 2012 to December 2014 inclusive of those without asthma, with asthma not using ICS, and with asthma using ICS. The most recent three-month HCC was measured by enzyme immunoassay and compared among the groups. Quantile regression analysis was performed to identify factors potentially affecting HCC. RESULTS: The median HCC was not significantly different among the children: No ICS (n = 47, 6.7 ng/g, interquartile range (IQR) 3.7-9.8 ng/g), ICS Treated (n = 360, 6.5 ng/g, IQR 3.8-14.3 ng/g), and Controls (n = 53, 5.8 ng/g, IQR 4.6-16.7 ng/g). 5.6% of the children using ICS had hair cortisol <2.0 ng/g compared to none in the control groups (P < .05, comparing ICS Treated (20/360) to all Controls combined (0/100)) and only half had been exposed to systemic corticosteroids. Age, sex, BMI, and intranasal corticosteroid use were significantly associated with HCC. CONCLUSIONS: Results suggest HCC may be a potential biomarker for adrenal suppression as a population of children using ICS with HCC < 2.0 ng/g was identified compared to none in the control groups. Further research is needed to determine if those children have or are at risk of adrenal suppression or insufficiency.

Spirometry-adjusted fraction of exhaled nitric oxide increases accuracy for assessment of asthma control in children.

Spirometry and exhaled nitric oxide are two important complimentary tools to identify and assess asthma control in children. We aimed to determine the ability of a new suggested spirometry-adjusted fraction of exhaled nitric oxide (NO) index in doing that. A random sample of 1602 schoolchildren were screened by a health questionnaire, skin prick tests, spirometry with bronchodilation and exhaled NO. A total of 662 children were included with median (IQR) exhaled NO 11(14) ppb. Receiver operating characteristic (ROC) curves using exhaled NO equations from Malmberg, Kovesi and Buchvald, and spirometry-adjusted fraction of exhaled NO values were applied to identify asthmatic children and uncontrolled asthma. Receiver operating characteristic (ROC) curves failed to identify asthmatic children (all AUC < 0.700). Spirometry-adjusted fraction of exhaled NO/FEV1 (AUC = 0.712; P = .010) and NO/FEF25%-75% (AUC = 0.735 P = .004) had a fair and increased ability to identify uncontrolled disease compared with exhaled NO (AUC = 0.707; P = .011) or the Malmberg equation (AUC = 0.701; P = .014). Sensitivity and specificity identifying non-controlled asthma were 59% and 81%, respectively, for the cut-off value of 9.7 ppb/L for exhaled NO/FEV1 , and 40% and 100% for 15.7 ppb/L/s for exhaled NO/FEF25%-75% . Exhaled NO did not allow to identify childhood asthma. Spirometry-adjusted fraction of exhaled NO performed better-assessing asthma control in children. Thus, although more validation studies are needed, we suggest its use in epidemiological studies to assess asthma control.

A novel pathway-based distance score enhances assessment of disease heterogeneity in gene expression.

BACKGROUND: Distance based unsupervised clustering of gene expression data is commonly used to identify heterogeneity in biologic samples. However, high noise levels in gene expression data and relatively high correlation between genes are often encountered, so traditional distances such as Euclidean distance may not be effective at discriminating the biological differences between samples. An alternative method to examine disease phenotypes is to use pre-defined biological pathways. These pathways have been shown to be perturbed in different ways in different subjects who have similar clinical features. We hypothesize that differences in the expressions of genes in a given pathway are more predictive of differences in biological differences compared to standard approaches and if integrated into clustering analysis will enhance the robustness and accuracy of the clustering method. To examine this hypothesis, we developed a novel computational method to assess the biological differences between samples using gene expression data by assuming that ontologically defined biological pathways in biologically similar samples have similar behavior. RESULTS: Pre-defined biological pathways were downloaded and genes in each pathway were used to cluster samples using the Gaussian mixture model. The clustering results across different pathways were then summarized to calculate the pathway-based distance score between samples. This method was applied to both simulated and real data sets and compared to the traditional Euclidean distance and another pathway-based clustering method, Pathifier. The results show that the pathway-based distance score performs significantly better than the Euclidean distance, especially when the heterogeneity is low and genes in the same pathways are correlated. Compared to Pathifier, we demonstrated that our approach achieves higher accuracy and robustness for small pathways. When the pathway size is large, by downsampling the pathways into smaller pathways, our approach was able to achieve comparable performance. CONCLUSIONS: We have developed a novel distance score that represents the biological differences between samples using gene expression data and pre-defined biological pathway information. Application of this distance score results in more accurate, robust, and biologically meaningful clustering results in both simulated data and real data when compared to traditional methods. It also has comparable or better performance compared to Pathifier.

Longterm clinical outcomes of omalizumab therapy in severe allergic asthma: Study of efficacy and safety.

Omalizumab has been shown to be an effective add-on therapy for patients with uncontrolled severe persistent allergic asthma. There has been a steady accumulation of evidence on the long-term effectiveness of omalizumab; however, data on real-life outcomes beyond one year of treatment is limited. In this study, we report on long-term outcomes of omalizumab treatment. We collected data from our severe asthma registry on hospitalisations, exacerbations, corticosteroid sparing, asthma control, lung function, biomarkers and side effects, to determine if the benefit was sustained and treatment was safe on the long term. Forty-five patients [mean age 44.9 years (range 19-69), females 37/45 (82%), mean duration of omalizumab treatment = 60.7 ± 30.9 months (range 23-121) were included in the analysis. We observed a reduction in the annual acute asthma related hospital admissions for the total population from 207 at baseline to 40 on treatment (80.7% reduction), whilst the per patient annual hospitalisations were reduced from a mean of 4.8 to 0.89 post-omalizumab treatment (p < 0.00001). There was a 76.7% reduction in daily mean maintenance OCS dose (prednisolone equivalent) from 25.8 mg (n = 43) to 6.0 mg (p < 0.0001), associated with clinically significant improvement in asthma control questionnaire (ACQ) from mean score of 4.1 (range 3.7-4.7) to 2.27 (range 0.5-4.1) p < 0.0001. The mean % predicted FEV1 has improved from 59.2% at baseline to 75.7% on treatment (p = 0.001). There was a statistically non-significant reduction in median peripheral blood eosinophils (PBE) from 300 cells/µl (range 40-1050) at baseline to 175 cells/µl (range 0-1500) post-treatment (p = 0.068), and statistically significant reduction of median fraction exhaled nitric oxide (FeNO) level from 37 parts per billion (range 12-178) to 24 ppb (range 7-50) (p = 0.0067). The work/school missed days were reduced in 17/19 patients who were at employment or school. The overall safety profile of the treatment seemed acceptable and was consistent with published experience. In conclusion, results from this real-life study demonstrate that improved outcomes in patients with severe allergic asthma are sustained with longer-term omalizumab therapy.

Serum cytokine profiles as predictors of asthma control in adults from the EGEA study.

BACKGROUND: To which extent serum cytokines may predict asthma control in adults remains understudied. OBJECTIVES: We investigated cross-sectional and longitudinal associations between cytokine profiles and asthma outcomes. METHODS: Serum interleukin (IL)-1Ra, IL-5, IL-7, IL-8, IL-10, IL-13 and TNF-α levels were determined in 283 adults with current asthma from the 2nd survey of the Epidemiological Study on the Genetics and Environment of Asthma (EGEA2). Participants were followed-up seven years later. Asthma symptom control was assessed according to GINA 2015 guidelines. Cytokine profiles were identified by principal component (PC) analyses, and expressed as above/below the median. RESULTS: The first two PCs captured 82.5% of the variability. While all seven cytokines scored high on PC1, only IL-1Ra and IL-10 scored high on PC2. At EGEA2, neither PC1 nor PC2 were related to exacerbations, asthma attacks, asthma symptom control, lung function, or allergic diseases. High level of PC1 (above the median) was associated with higher blood neutrophil counts (P = 0.02), while high level of PC2 was associated with lower IgE levels (P = 0.04). High level of PC2 at EGEA2 was associated with lower bronchial hyperresponsiveness (adjusted(a) OR[95%CI] = 0.46[0.23; 0.91]) and with subsequent lower risk of worsening asthma control and attacks (aOR[95%CI] = 0.24[0.09; 0.60]; 0.31[0.11; 0.85] respectively). CONCLUSIONS: Serum cytokine profiles with high levels of IL-1Ra and IL-10 were associated with lower subsequent risks of worsening asthma control and attacks in adults. This study adds new findings for the role of serum cytokine profiles to help identifying adults with subsequent risk of asthma burden that could be targeted for specific therapies.