Understanding uncontrolled severe allergic asthma by integration of omic and clinical data.

BACKGROUND: Asthma is a complex, multifactorial disease often linked with sensitization to house dust mites (HDM). There is a subset of patients that does not respond to available treatments, who present a higher number of exacerbations and a worse quality of life. To understand the mechanisms of poor asthma control and disease severity, we aim to elucidate the metabolic and immunologic routes underlying this specific phenotype and the associated clinical features. METHODS: Eighty-seven patients with a clinical history of asthma were recruited and stratified in 4 groups according to their response to treatment: corticosteroid-controlled (ICS), immunotherapy-controlled (IT), biologicals-controlled (BIO) or uncontrolled (UC). Serum samples were analysed by metabolomics and proteomics; and classifiers were built using machine-learning algorithms. RESULTS: Metabolomic analysis showed that ICS and UC groups cluster separately from one another and display the highest number of significantly different metabolites among all comparisons. Metabolite identification and pathway enrichment analysis highlighted increased levels of lysophospholipids related to inflammatory pathways in the UC patients. Likewise, 8 proteins were either upregulated (CCL13, ARG1, IL15 and TNFRSF12A) or downregulated (sCD4, CCL19 and IFNγ) in UC patients compared to ICS, suggesting a significant activation of T cells in these patients. Finally, the machine-learning model built including metabolomic and clinical data was able to classify the patients with an 87.5% accuracy. CONCLUSIONS: UC patients display a unique fingerprint characterized by inflammatory-related metabolites and proteins, suggesting a pro-inflammatory environment. Moreover, the integration of clinical and experimental data led to a deeper understanding of the mechanisms underlying UC phenotype.

Bioremediation of an agricultural saline soil contaminated with endosulfan and Escherichia coli by an active surface agent induced in a Penicillium crustosum culture.

This study evaluates the production of a biological active surface agent (BASA) through its surface tension (ST) and emulsifying activity (E24) for endosulfan degradation (ED) and Escherichia coli growth inhibition (EcGI) in an agricultural saline soil. The fungus, identified as Penicillium crustosum was isolated from the Citrus sinensis peel (CsP), then the surface properties were evaluated in 9 culture media through a Taguchi L9 experimental design. The culture conditions included: stirring speed, pH, carbon (C) and nitrogen (N) sources; being glucose, NH4N03, 120 rpm and pH of 5, the most significant parameters in the BASA production. The BASA identified as a lipopeptide type, showed a ST = 38 mN m-1 and E24=71%. Both properties were stable at 80 °C, while ST presented stability in the pH range of 2 - 12, and a saline concentration of 200 g L-1; E24 was also stable at a pH between 8-12. Further application of BASA and fungal inoculum to a contaminated agricultural saline soil presented an EcGI of 99.8% on the 8th day, and ED of 92.9 ± 4.7% in 30 days, respectively; being the first report that uses this fungus for pesticide and bacteria elimination from an agricultural saline soil.

Saharan dust and the impact on adult and elderly allergic patients: the effect of threshold values in the northern sector of Gran Canaria, Spain.

Gran Canaria Island is frequently impacted by Saharan dust, a health hazard of particular concern to the island population and health agencies. Airborne mineral dust has the severest impact on the higher age groups of the population, and those with respiratory conditions; despite that, on average, the ambient particulate matter (PM) concentrations fall within international PM guidelines. During 2010 and 2011, an epidemiological survey, in parallel with an air quality study, was conducted at the Dr Negrín hospital in Gran Canaria. This included the quarterly monitoring of outpatients and recording of emergency patients with respiratory diseases, together with the measurement of aerosol, meteorological, and PM-related air quality levels. The finer more toxic particles were collected with PM2.5 (particulate matter with aerodynamic diameter less than 2.5 µm) aerosol samplers. The filter samples were gravimetrically and chemically analyzed for their elemental, water-soluble ions, carbon, and mineralogical contents. Individual particle morphology was measured by Scanning Electron Microscopy. Statistical analysis of the chemical and clinical data included the analysis of variance and calculation of Spearman correlation coefficients. No statistically significant relations were found between the allergic control group, the emergency room admissions, pulmonary conditions, medication, and elevated Saharan dust levels. However, changing environmental conditions, such as an increase in humidity or a reduction in ambient air temperature made a significant difference to the outcomes recorded on the health statements of the allergic and respiratory illness groups of the Gran Canary population.

Efficacy and safety of sublingual tablets of house dust mite allergen extracts in adults with allergic rhinitis.

BACKGROUND: Preliminary studies have suggested the efficacy of sublingual tablets of house dust mite (HDM) extracts in adults with allergic rhinitis. OBJECTIVES: We sought to assess the efficacy and safety of 2 doses of HDM sublingual tablets over 1 treatment year and the subsequent immunotherapy-free year. METHODS: Adults with HDM-associated allergic rhinitis were randomized in a double-blind, placebo-controlled study to receive 500 index of reactivity (IR) tablets, 300IR tablets, or placebo administered once daily for 1 year and were followed for the subsequent year. The primary efficacy variable was the Average Adjusted Symptom Score over the year 1 primary period (ie, October 1 to December 31). Symptoms and rescue medication scores, onset of action, patient-reported outcomes, and safety were secondary variables. The same end points were evaluated during the immunotherapy-free year. The primary efficacy end point was analyzed by using analysis of covariance. RESULTS: Five hundred nine participants were randomized, and 427 continued in the immunotherapy-free year. Both the 500IR and 300IR HDM sublingual tablets significantly reduced mean Average Adjusted Symptom Scores compared with placebo by -20.2% (P = .0066) and -17.9% (P = .0150), respectively. Efficacy of both doses was maintained during the treatment-free follow-up phase. The onset of action was at 4 months. Participants' global evaluation of treatment success was significantly higher in the 500IR and 300IR groups compared with the placebo group (P = .0206 and P = .0001, respectively). Adverse events were generally application-site reactions. There were no reports of anaphylaxis. CONCLUSIONS: Twelve months of treatment with 500IR and 300IR sublingual tablets of HDM allergen extracts was efficacious and well tolerated. Efficacy was maintained during the treatment-free follow-up year.

Potential impact of mepolizumab in stepping down anti-osteporotic treatment in corticosteroid-dependent asthma.

Oral corticosteroids (OCS) are commonly used for the acute management of severe asthma exacerbations or as maintenance therapy; however, chronic use is associated with significant toxicities, e.g., osteoporosis. In the REal worlD Effectiveness and Safety (REDES) study of mepolizumab in a multicentric Spanish cohort of asthma patients, mepolizumab effectively reduced clinically severe asthma exacerbations and decreased OCS dependence. This post-hoc analysis further evaluates mepolizumab's de-escalation effect on OCS dose. Patients enrolled in REDES who had OCS consumption data available for 12 months pre- and post-mepolizumab treatment were included in this analysis. Primary outcomes were to determine the change in the proportion of patients eligible for anti-osteoporotic treatment due to the changes in OCS consumption before and after 1 year of mepolizumab treatment. All analyses are descriptive. Approximately one-third (98/318; 30.8%) of patients in REDES were on maintenance OCS at the time of mepolizumab treatment initiation. In REDES, mean cumulative OCS exposure decreased by 54.3% after 1 year of treatment. The proportion of patients on high-dose OCS (≥7.5 mg/day) fell from 57.1% at baseline to 28.9% after 12 months of mepolizumab treatment. Thus, 53.6% of OCS-dependent asthma patients treated with mepolizumab would cease to be candidates for anti-osteoporotic treatment according to guidelines thresholds.

No association between genetic ancestry and susceptibility to asthma or atopy in Canary Islanders.

Asthma is a complex respiratory disease characterized by chronic inflammation of airways and frequently associated with atopic symptoms. The population from the Canary Islands, which has resulted from a recent admixture of North African and Iberian populations, shows the highest prevalence of asthma and atopic symptoms among the Spanish populations. Although environmental particularities would account for the majority of such disparity, genetic ancestry might play a role in increasing the susceptibility of asthma or atopy, as have been demonstrated in other recently African-admixed populations. Here, we aimed to explore whether genetic ancestry was associated with asthma or related traits in the Canary Islanders. For that, a total of 734 DNA samples from unrelated individuals of the GOA study, self-reporting at least two generations of ancestors from the Canary Islands (391 asthmatics and 343 controls), were successfully genotyped for 83 ancestry informative markers (AIMs), which allowed to precisely distinguishing between North African and Iberian ancestries. No association was found between genetic ancestry and asthma or related traits after adjusting by demographic variables differing among compared groups. Similarly, none of the individual AIMs was associated with asthma when results were considered in the context of the multiple comparisons performed (0.005 ≤ p value ≤ 0.042; 0.221 ≤ q value ≤ 0.443). Our results suggest that if genetic ancestry were involved in the susceptibility to asthma or related traits among Canary Islanders, its effects would be modest. Larger studies, examining more genetic variants, would be needed to explore such possibility.

Development of a Novel Targeted Metabolomic LC-QqQ-MS Method in Allergic Inflammation.

The transition from mild to severe allergic phenotypes is still poorly understood and there is an urgent need of incorporating new therapies, accompanied by personalized diagnosis approaches. This work presents the development of a novel targeted metabolomic methodology for the analysis of 36 metabolites related to allergic inflammation, including mostly sphingolipids, lysophospholipids, amino acids, and those of energy metabolism previously identified in non-targeted studies. The methodology consisted of two complementary chromatography methods, HILIC and reversed-phase. These were developed using liquid chromatography, coupled to triple quadrupole mass spectrometry (LC-QqQ-MS) in dynamic multiple reaction monitoring (dMRM) acquisition mode and were validated using ICH guidelines. Serum samples from two clinical models of allergic asthma patients were used for method application, which were as follows: (1) corticosteroid-controlled (ICS, n = 6) versus uncontrolled (UC, n = 4) patients, and immunotherapy-controlled (IT, n = 23) versus biologicals-controlled (BIO, n = 12) patients. The results showed significant differences mainly in lysophospholipids using univariate analyses in both models. Multivariate analysis for model 1 was able to distinguish both groups, while for model 2, the results showed the correct classification of all BIO samples within their group. Thus, this methodology can be of great importance for further understanding the role of these metabolites in allergic diseases as potential biomarkers for disease severity and for predicting patient treatment response.

Contribution of allergy in the acquisition of uncontrolled severe asthma.

Asthma is a multifactorial, heterogeneous disease that has a challenging management. It can be divided in non-allergic and allergic (usually associated with house dust mites (HDM) sensitization). There are several treatments options for asthma (corticosteroids, bronchodilators, antileukotrienes, anticholinergics,…); however, there is a subset of patients that do not respond to any of the treatments, who can display either a T2 or a non-T2 phenotype. A deeper understanding of the differential mechanisms underlying each phenotype will help to decipher the contribution of allergy to the acquisition of this uncontrolled severe phenotype. Here, we aim to elucidate the biological pathways associated to allergy in the uncontrolled severe asthmatic phenotype. To do so, twenty-three severe uncontrolled asthmatic patients both with and without HDM-allergy were recruited from Hospital Universitario de Gran Canaria Dr. Negrin. A metabolomic fingerprint was obtained through liquid chromatography coupled to mass spectrometry, and identified metabolites were associated with their pathways. 9/23 patients had uncontrolled HDM-allergic asthma (UCA), whereas 14 had uncontrolled, non-allergic asthma (UCNA). 7/14 (50%) of the UCNA patients had Aspirin Exacerbated Respiratory Disease. There were no significant differences regarding gender or body mass index; but there were significant differences in age and onset age, which were higher in UCNA patients; and in total IgE, which was higher in UCA. The metabolic fingerprint revealed that 103 features were significantly different between UCNA and UCA (p < 0.05), with 97 being increased in UCA and 6 being decreased. We identified lysophosphocholines (LPC) 18:2, 18:3 and 20:4 (increased in UCA patients); and deoxycholic acid and palmitoleoylcarnitine (decreased in UCA). These metabolites were related with a higher activation of phospholipase A2 (PLA2) and other phospholipid metabolism pathways. Our results show that allergy induces the activation of specific inflammatory pathways, such as the PLA2 pathway, which supports its role in the development of an uncontrolled asthma phenotype. There are also clinical differences, such as higher levels of IgE and earlier onset ages for the allergic asthmatic group, as expected. These results provide evidences to better understand the contribution of allergy to the establishment of a severe uncontrolled phenotype.

Greater epitope recognition of shrimp allergens by children than by adults suggests that shrimp sensitization decreases with age.

BACKGROUND: Shellfish allergy is a long-lasting disorder typically affecting adults. Despite its high prevalence, there is limited information about allergenic shrimp proteins and the epitopes implicated in such allergic reactions. OBJECTIVE: We sought to identify the IgE-binding epitopes of the 4 shrimp allergens and to characterize epitope recognition profiles of children and adults with shrimp allergy. METHODS: Fifty-three subjects, 34 children and 19 adults, were selected with immediate allergic reactions to shrimp, increased shrimp-specific serum IgE levels, and positive immunoblot binding to shrimp. Study subjects and 7 nonatopic control subjects were tested by means of peptide microarray for IgE binding with synthetic overlapping peptides spanning the sequences of Litopenaeus vannamei shrimp tropomyosin, arginine kinase (AK), myosin light chain (MLC), and sarcoplasmic calcium-binding protein (SCP). The Wilcoxon test was used to determine significant differences in z scores between patients and control subjects. RESULTS: The median shrimp IgE level was 4-fold higher in children than in adults (47 vs 12.5 kU(A)/L). The frequency of allergen recognition was higher in children (tropomyosin, 81% [94% for children and 61% for adults]; MLC, 57% [70% for children and 31% for adults]; AK, 51% [67% for children and 21% for adults]; and SCP, 45% [59% for children and 21% for adults]), whereas control subjects showed negligible binding. Seven IgE-binding regions were identified in tropomyosin by means of peptide microarray, confirming previously identified shrimp epitopes. In addition, 3 new epitopes were identified in tropomyosin (epitopes 1, 3, and 5b-c), 5 epitopes were identified in MLC, 3 epitopes were identified in SCP, and 7 epitopes were identified in AK. Interestingly, frequency of individual epitope recognition, as well as intensity of IgE binding, was significantly greater in children than in adults for all 4 proteins. CONCLUSIONS: Children with shrimp allergy have greater shrimp-specific IgE antibody levels and show more intense binding to shrimp peptides and greater epitope diversity than adults.

Differences among pollen-allergic patients with and without plant food allergy.

BACKGROUND: A considerable number of pollen-allergic patients develops allergy to plant foods, which has been attributed to cross-reactivity between food and pollen allergens. The aim of this study was to analyze the differences among pollen-allergic patients with and without plant food allergy. METHODS: Eight hundred and six patients were recruited from 8 different hospitals. Each clinical research group included 100 patients (50 plant food-allergic patients and 50 pollen-allergic patients). Diagnosis of pollen allergy was based on typical case history of pollen allergy and positive skin prick tests. Diagnosis of plant-food allergy was based on clear history of plant-food allergy, skin prick tests and/or plant-food challenge tests. A panel of 28 purified allergens from pollens and/or plant foods was used to quantify specific IgE (ADVIA-Centaur® platform). RESULTS: Six hundred and sixty eight patients (83%) of the 806 evaluated had pollen allergy: 396 patients with pollen allergy alone and 272 patients with associated food and pollen allergies. A comparison of both groups showed a statistically significant increase in the food and pollen allergy subgroup in frequency of: (1) asthma (47 vs. 59%; p < 0.001); (2) positive skin test results to several pollens: Plantago, Platanus, Artemisia, Betula, Parietaria and Salsola (p < 0.001); (3) sensitization to purified allergens: Pru p 3, profilin, Pla a 1 - Pla a 2, Sal k 1, PR-10 proteins and Len c 1. CONCLUSION: Results showed relevant and significant differences between both groups of pollen-allergic patients depending on whether or not they suffered from plant-derived food allergy.

Sarcoplasmic calcium-binding protein is an EF-hand-type protein identified as a new shrimp allergen.

BACKGROUND: Shellfish allergy is a long-lasting disorder usually persisting throughout life. Despite its high prevalence, there is limited information about allergenic shrimp proteins. OBJECTIVE: Characterization of shrimp allergens. METHODS: Fifty-two adults and children with a history of immediate allergic reactions to shrimp and elevated serum IgE to shrimp were selected for this study. Tryptic digests from a 20-kd IgE-binding protein were analyzed by LC-MS/MS, identifying the protein as a sarcoplasmic-calcium-binding protein. cDNA encoding sarcoplasmic calcium-binding protein (SCP) from a shrimp cDNA library (Litopenaeus vannamei) was amplified by PCR, cloned into an expression vector, and sequenced. Recombinant SCP was tested with patients' sera. ELISA inhibition experiments determined the fraction of total shrimp IgE recognizing SCP. A functional assay with a rat basophilic leukemia cell line was used to determine the capacity for mediator release induced by SCP. RESULTS: Immunoblotting demonstrated IgE binding by 31 of 52 (59.6%) of the sera to a 20-kd shrimp protein. The protein was identified as a SCP. Amplified cDNA encoding SCP was isolated and sequenced. Open reading frame translation provided the complete amino acid sequence of shrimp SCP. Recombinant SCP was recognized by serum IgE from 20 of 52 (38.4%) subjects, of whom 17 of 20 (85%) were children. ELISA inhibition of pooled sera IgE reactivity to BS extract using recombinant SCP was significant (as high as 79%). For some subjects, mediator release induced by recombinant SCP was higher than that induced by recombinant tropomyosin. CONCLUSION: We have identified and cloned a new shrimp allergen, Lit v 4.0101, an SCP, which appears to be of particular importance in the pediatric population.

Myosin light chain is a novel shrimp allergen, Lit v 3.

BACKGROUND: Shellfish allergy is a prevalent, long-lasting disorder usually persisting throughout life. Few options are available for treatment, and avoidance is the only therapy recommended. OBJECTIVE: We sought to identify relevant crustacean allergens for use as diagnostic and safe immunotherapeutic agents for subjects with shellfish allergy. METHODS: Thirty-eight patients were selected with immediate allergic reactions to shrimp and increased shrimp-specific serum IgE levels. One-dimensional and 2-dimensional electrophoresis of shrimp extracts were followed by IgE immunoblotting. Protein identification was done with matrix-assisted laser desorption/ionization-mass spectrometry and Edman sequencing. A cDNA library was generated from white pacific shrimp (Litopenaeus vannamei) and screened with primers designed on the basis of internal sequences obtained from 2-dimensional tryptic digests. Full-length cDNA clones were isolated from the library and sequenced. Recombinant protein was expressed and tested with sera from patients with shrimp allergy. RESULTS: Immunoblotting demonstrated IgE binding to a 20-kDa shrimp protein by 21 (55%) of 38 sera. Tryptic digestion of the protein followed by matrix-assisted laser desorption/ionization-mass spectrometric analysis and Edman sequencing identified it as a myosin light chain (MLC). Screening of the shrimp cDNA library resulted in isolation of a novel protein cDNA. Open reading frame translation provided the amino acid sequence of a new allergenic shrimp protein with high similarity to Bla g 8 (cockroach MLC). Recombinant protein was recognized by 17 patients, confirming the allergenicity of shrimp MLC. CONCLUSIONS: We have identified and cloned a new major shrimp allergen, Lit v 3.0101, an MLC protein.

Troubleshooting in Large-Scale LC-ToF-MS Metabolomics Analysis: Solving Complex Issues in Big Cohorts.

Metabolomics, understood as the science that manages the study of compounds from the metabolism, is an essential tool for deciphering metabolic changes in disease. The experiments rely on the use of high-throughput analytical techniques such as liquid chromatography coupled to mass spectrometry (LC-ToF MS). This hyphenation has brought positive aspects such as higher sensitivity, specificity and the extension of the metabolome coverage in a single run. The analysis of a high number of samples in a single batch is currently not always feasible due to technical and practical issues (i.e., a drop of the MS signal) which result in the MS stopping during the experiment obtaining more than a single sample batch. In this situation, careful data treatment is required to enable an accurate joint analysis of multi-batch data sets. This paper summarizes the analytical strategies in large-scale metabolomic experiments; special attention has been given to QC preparation troubleshooting and data treatment. Moreover, labeled internal standards analysis and their aim in data treatment, and data normalization procedures (intra- and inter-batch) are described. These concepts are exemplified using a cohort of 165 patients from a study in asthma.

Sputum eosinophilia and maximal airway narrowing in Dermatophagoides pteronyssinus allergic rhinitis patients: only rhinitis or rhinitis plus mild asthma?

STUDY OBJECTIVE: To study the existence of bronchial disease among rhinitis patients. To evaluate the laboratory test or set of tests (ie, symptoms, exposure, and sensitization to the allergen, and the provocative dose of methacholine [Mth] causing a 20% fall in FEV(1) [PD(20)] and the maximal response plateau [MRP] to Mth) that best identifies a case of mild asthma. DESIGN: Cross-sectional analysis in 52 Dermatophagoides pteronyssinus-monosensitized patients who were consulting a physician for perennial rhinitis. SETTING: Allergy Department, Hospital Doctor Negrín, Las Palmas, Grand Canary Island, Spain. INTERVENTIONS AND MEASUREMENTS: Patients filled out a standardized asthma symptom questionnaire, and underwent sputum induction and Mth challenge in which 40% falls in FEV(1) were attained. Dose-response curves were expressed in terms of both PD(20) values and the level of the MRP. D pteronyssinus allergen exposure was assessed in dust samples from patients' beds. RESULTS: No difference between patients who positively responded to the questionnaire and those who did not was observed. Mth-PD(20) values were not detected in 13% of the patients reporting bronchial symptoms, and an MRP was not identified in 59% of the subjects who did not respond positively. A higher degree of allergen sensitization (ascertained from skin test results, and total and specific serum IgE levels) and higher degree of sputum eosinophilia were detected in subjects in whom an MRP had not been identified. The presence of sputum eosinophilia provided the best differentiation between those patients who presented with an MRP and those who did not. CONCLUSION: The individual perception of bronchial symptoms is highly variable among perennial allergic rhinitis patients. The lack of a maximal airway-narrowing plateau is related to the presence of sputum eosinophilia, which might be useful in the detection of patients susceptible to anti-inflammatory therapy. Prospective studies evaluating whether these patients are more likely to develop symptomatic asthma in the future and if the early anti-inflammatory treatment prevents its development are needed.

Assessing the validity of asthma associations for eight candidate genes and age at diagnosis effects.

BACKGROUND: Before the advent of genome-wide association studies (GWAS), ADAM33, ADRB2, CD14, MS4A2 (alias FCER1B), IL13, IL4, IL4R, and TNF constituted the most replicated non-HLA candidate genes with asthma and related traits. However, except for the IL13-IL4 region, none of these genes have been found in close proximity of genome-wide significant hits among GWAS for asthma or related traits. Here we aimed to assess the reproducibility of these asthma associations and to test if associations were more evident considering the effect of age at diagnosis. METHODOLOGY/PRINCIPAL FINDINGS: We systematically evaluated 286 common single nucleotide polymorphisms (SNPs) of these 8 genes in a sample of 1,865 unrelated Spanish individuals (606 asthmatics and 1,259 controls). We found that variants at MS4A2, IL4R and ADAM33 genes demonstrated varying association effects with the age at diagnosis of asthma, with 10 SNPs showing study-wise significance after the multiple comparison adjustment. In addition, in silico replication with GWAS data supported the association of IL4R. CONCLUSIONS/SIGNIFICANCE: Our results support the important role of MS4A2, IL4R and ADAM33 genes in asthma and/or atopy susceptibility. However, additional studies in larger samples sets are needed to firmly implicate these genes in asthma susceptibility, and also to identify the causal variation underlying the associations found.