Signature Proteins in Small Extracellular Vesicles of Granulocytes and CD4+ T-Cell Subpopulations Identified by Comparative Proteomic Analysis.

Several studies have described the proteomic profile of different immune cell types, but only a few have also analysed the content of their delivered small extracellular vesicles (sEVs). The aim of the present study was to compare the protein signature of sEVs delivered from granulocytes (i.e., neutrophils and eosinophils) and CD4+ T cells (i.e., TH1, TH2, and TH17) to identify potential biomarkers of the inflammatory profile in chronic inflammatory diseases. Qualitative (DDA) and quantitative (DIA-SWATH) analyses of in vitro-produced sEVs revealed proteome variations depending on the cell source. The main differences were found between granulocyte- and TH cell-derived sEVs, with a higher abundance of antimicrobial proteins (e.g., LCN2, LTF, MPO) in granulocyte-derived sEVs and an enrichment of ribosomal proteins (RPL and RPS proteins) in TH-derived sEVs. Additionally, we found differentially abundant proteins between neutrophil and eosinophil sEVs (e.g., ILF2, LTF, LCN2) and between sEVs from different TH subsets (e.g., ISG15, ITGA4, ITGB2, or NAMPT). A "proof-of-concept" assay was also performed, with TH2 biomarkers ITGA4 and ITGB2 displaying a differential abundance in sEVs from T2high and T2low asthma patients. Thus, our findings highlight the potential use of these sEVs as a source of biomarkers for diseases where the different immune cell subsets studied participate, particularly chronic inflammatory pathologies such as asthma or chronic obstructive pulmonary disease (COPD).

Biomarker Profiles Associated with COVID-19 Severity and Mortality.

INTRODUCTION: The aim of this study was to analyze biomarkers that might predict the severity and progression of the SARS-CoV-2 infection, both in the acute phase and after recovery. METHODS: Unvaccinated patients infected with the original strain of COVID-19 requiring ward (Group 1, n = 48) or ICU (Group 2, n = 41) admission were included. At the time of admission (visit 1), a clinical history was acquired, and blood samples were obtained. One and six months after discharge from the hospital (visits 2 and 3, respectively), a clinical history, lung function tests, and blood samples were carried out. At visit 2, patients also underwent a chest CT scan. Different cytokines (IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, IL-17A, G-CSF, GM-CSF, IFN-É£, MCP-1, MIP-1ß, and TNF-α) and lung fibrosis biomarkers (YKL-40 and KL-6) were measured in blood samples obtained at visits 1, 2, and 3. RESULTS: At visit 1, IL-4, IL-5, and IL-6 levels were higher in Group 2 (p = 0.039, 0.011, and 0.045, respectively), and IL-17 and IL-8 levels were higher in Group 1 (p = 0.026 and 0.001, respectively). The number of patients in Groups 1 and 2 who died during hospitalization was 8 and 11, respectively. YKL-40 and KL-6 levels were higher in patients who died. Serum YKL-40 and KL-6 levels determined at visit 2 correlated negatively with FVC (p = 0.022 and p = 0.024, respectively) and FEV1 (p = 0.012 and p = 0.032, respectively) measured at visit 3. KL-6 levels also correlated negatively with the diffusing capacity of the lungs for carbon monoxide (DLCO, p = 0.001). CONCLUSIONS: Patients who required ICU admission had higher levels of Th2 cytokines, while patients admitted to the ward showed an innate immune response activation, with IL-8 release and Th1/Th17 lymphocyte contribution. Increased levels of YKL-40 and KL-6 were associated with mortality in COVID-19 patients.

Admixture mapping of severe asthma exacerbations in Hispanic/Latino children and youth.

BACKGROUND: In the USA, genetically admixed populations have the highest asthma prevalence and severe asthma exacerbations rates. This could be explained not only by environmental factors but also by genetic variants that exert ethnic-specific effects. However, no admixture mapping has been performed for severe asthma exacerbations. OBJECTIVE: We sought to identify genetic variants associated with severe asthma exacerbations in Hispanic/Latino subgroups by means of admixture mapping analyses and fine mapping, and to assess their transferability to other populations and potential functional roles. METHODS: We performed an admixture mapping in 1124 Puerto Rican and 625 Mexican American children with asthma. Fine-mapping of the significant peaks was performed via allelic testing of common and rare variants. We performed replication across Hispanic/Latino subgroups, and the transferability to non-Hispanic/Latino populations was assessed in 1001 African Americans, 1250 Singaporeans and 941 Europeans with asthma. The effects of the variants on gene expression and DNA methylation from whole blood were also evaluated in participants with asthma and in silico with data obtained through public databases. RESULTS: Genomewide significant associations of Indigenous American ancestry with severe asthma exacerbations were found at 5q32 in Mexican Americans as well as at 13q13-q13.2 and 3p13 in Puerto Ricans. The single nucleotide polymorphism (SNP) rs1144986 (C5orf46) showed consistent effects for severe asthma exacerbations across Hispanic/Latino subgroups, but it was not validated in non-Hispanics/Latinos. This SNP was associated with DPYSL3 DNA methylation and SCGB3A2 gene expression levels. CONCLUSIONS: Admixture mapping study of asthma exacerbations revealed a novel locus that exhibited Hispanic/Latino-specific effects and regulated DPYSL3 and SCGB3A2.

A longitudinal and multidesign epidemiological study to analyze the effect of the volcanic eruption of Tajogaite volcano (La Palma, Canary Islands). The ASHES study protocol.

INTRODUCTION: Volcanic eruptions emit gases and particulate matter into the atmosphere which, if inhaled, can have an impact on health. The eruption of the volcano situated in the Cumbre Vieja Nature Reserve (La Palma, Canary Islands, Spain) affords a unique opportunity to study the effect of such a phenomenon on health. The aim of the proposed study is to assess the short-, medium- and long-term respiratory health effects of exposure to volcanic emissions from the eruption in three different population groups. METHODS: We propose to undertake a multidesign study: an ambispective cohort study to analyze the effect of the eruption on the general population, the highly exposed population, and the childhood population; and a pre-post quasi-experimental study on subjects with previously diagnosed respiratory diseases. The information will be collected using a personal interview, biologic specimens, air pollution data, data from medical records, respiratory tests and imaging tests. The study has an envisaged follow-up of five years, to run from the date of initial recruitment, with annual data-collection. This study has been approved by the Santa Cruz de Tenerife Provincial Research Ethics Committee (Canary Island Health Service) on March 10, 2022. CONCLUSIONS: This study will make it possible to advance our knowledge of the effect a volcano eruption has on population health, both short- and long-term, and to assess the potential respiratory injury attributable to volcanic eruptions. It may serve as a model for future studies of new volcanic eruptions in the coming years.

Immunopathological Mechanisms of Bird-Related Hypersensitivity Pneumonitis.

Bird-related hypersensitivity pneumonitis (BRHP) is an interstitial lung disease induced by avian proteins. The immunopathological pathways involved in the disease are still unknown. This study assesses the cellular immune response and the cytokine pattern in a mouse model of BRHP. On days -3 and -1, mice were intraperitoneally sensitized with commercial pigeon serum (PS) or saline. Intranasal instillations with PS or saline were carried out on three consecutive days/week over either 3 weeks (Group 1) or 12 weeks (Group 2). Leukocyte and cytokine patterns in lung tissue and pulmonary inflammation in bronchoalveolar lavage (BAL) were analysed. Both groups presented increases in resident monocytes, interstitial macrophages and type 2 dendritic cells (DCs), but also reductions in inflammatory monocytes, alveolar macrophages and tolerogenic DCs compared with their control groups. Group 1 had increased levels of eosinophils and T cells with reductions in neutrophils and B cells, while Group 2 showed high levels of B cells. Both groups exhibited increases in Th1 and Th2 cytokines. Group 2 also showed increased levels of IL-23, a Th17 cytokine. Increased levels of neutrophils, eosinophils and lymphocytes were observed in BAL samples of both groups compared with controls. In the first stages of BRHP, there is a mixed Th1/Th2 immune response, while during the progression of the disease, although there is a Th1 response, the cytokine levels seem to indicate a switch towards a Th2/Th17 mixed response.

Analysis of Differentially Expressed MicroRNAs in Serum and Lung Tissues from Individuals with Severe Asthma Treated with Oral Glucocorticoids.

Nowadays, microRNAs (miRNAs) are increasingly used as biomarkers due to their potential contribution to the diagnosis and targeted treatment of a range of diseases. The aim of the study was to analyze the miRNA expression profiles in serum and lung tissue from patients with severe asthma treated with oral corticosteroids (OCS) and those without OCS treatment. For this purpose, serum and lung tissue miRNAs of OCS and non-OCS asthmatic individuals were evaluated by miRNAs-Seq, and subsequently miRNA validation was performed using RT-qPCR. Additionally, pathway enrichment analysis of deregulated miRNAs was conducted. We observed altered expression by the next-generation sequencing (NGS) of 11 miRNAs in serum, of which five (hsa-miR-148b-3p, hsa-miR-221-5p, hsa-miR-618, hsa-miR-941, and hsa-miR-769-5p) were validated by RT-qPCR, and three miRNAs in lung tissue (hsa-miR-144-3p, hsa-miR-144-5p, and hsa-miR-451a). The best multivariate logistic regression model to differentiate individuals with severe asthma, treated and untreated with OCS, was to combine the serum miRNAs hsa-miR-221-5p and hsa-miR-769-5p. Expression of hsa-miR-148b-3p and hsa-miR-221-5p correlated with FEV1/FVC (%) and these altered miRNAs act in key signaling pathways for asthma disease and the regulated expression of some genes (FOXO3, PTEN, and MAPK3) involved in these pathways. In conclusion, there are miRNA profiles differentially expressed in OCS-treated individuals with asthma and could be used as biomarkers of OCS treatment.

Multiple Copies of flhDC in Paraburkholderia unamae Regulate Flagellar Gene Expression, Motility, and Biofilm Formation.

FlhDC is a heterohexameric complex that acts as a master regulator of flagellar biosynthesis genes in numerous bacteria. Previous studies have identified a single flhDC operon encoding this complex. However, we found that two flhDC loci are present throughout Paraburkholderia, and two additional flhC copies are also present in Paraburkholderia unamae. Systematic deletion analysis in P. unamae of the different flhDC copies showed that one of the operons, flhDC1, plays the predominant role, with deletion of its genes resulting in a severe inhibition of motility and biofilm formation. Expression analysis using promoter-lacZ fusions and real-time quantitative PCR support the primary role of flhDC1 in flagellar gene regulation, with flhDC2 a secondary contributor. Phylogenetic analysis shows the presence of the flhDC1 and flhDC2 operons throughout Paraburkholderia. In contrast, Burkholderia and other bacteria only carry the copy syntenous with flhDC2. The variations in impact each copy of flhDC has on downstream processes indicate that regulation of FlhDC in P. unamae, and likely other Paraburkholderia species, is regulated at least in part by the presence of multiple copies of these genes. IMPORTANCE Motility is important in the colonization of plant roots by beneficial and pathogenic bacteria, with flagella playing essential roles in host cell adhesion, entrance, and biofilm formation. Flagellar biosynthesis is energetically expensive. Its complex regulation by the FlhDC master regulator is well studied in peritrichous flagella expressing enterics. We report the unique presence throughout Paraburkholderia of multiple copies of flhDC. In P. unamae, the flhDC1 copy showed higher expression and a greater effect on swim motility, flagellar development, and regulation of downstream genes, than the flhDC2 copy that is syntenous to flhDC in Escherichia coli and pathogenic Burkholderia spp. The flhDC genes have evolved differently in these plant-growth-promoting bacteria, giving an additional layer of complexity in gene regulation by FlhDC.

Benefit of switching to mepolizumab from omalizumab in severe eosinophilic asthma based on patient characteristics.

BACKGROUND: The OSMO study assessed the efficacy of switching to mepolizumab in patients with severe eosinophilic asthma that was uncontrolled whilst receiving omalizumab. The objective of this analysis was to assess the proportion of patients achieving pre-defined improvements in up to four efficacy outcomes and the relationship between patient baseline characteristics and treatment response. METHODS: This was a post hoc analysis of OSMO study data (GSK ID:204471; ClinicalTrials.gov No. NCT02654145). Patients with severe eosinophilic asthma uncontrolled by high-dose inhaled corticosteroids, other controller(s) and omalizumab subcutaneously (≥ 4 months) were switched to mepolizumab 100 mg administered subcutaneously. Endpoints included the proportion of responders-i.e. patients achieving a pre-defined clinical improvement in ≥ 1 of the following outcomes: (1) Asthma Control Questionnaire (ACQ)-5 score (≥ 0.5-points), (2) St George's Respiratory Questionnaire (SGRQ) total score (≥ 4-points), (3) pre-bronchodilator forced expiratory volume in 1s (FEV1; ≥ 100 mL), all at Week 32, and (4) annualised rate of clinically significant exacerbations (≥ 50% reduction). RESULTS: Of the 145 patients included, 94%, 83%, 63% and 31% were responders for ≥ 1, ≥ 2, ≥ 3 and 4 outcomes, respectively; 75% and 78% were ACQ-5 and SGRQ score responders, and 50% and 69% were FEV1 and exacerbation responders. Subgroup analyses demonstrated improvements irrespective of baseline blood eosinophil count, prior omalizumab treatment regimen/duration, comorbidities, prior exacerbation history, maintenance oral corticosteroid use, ACQ-5 and SGRQ scores, and body weight/body mass index. CONCLUSIONS: After switching to mepolizumab, almost all patients with uncontrolled severe eosinophilic asthma on omalizumab achieved a beneficial response in ≥ 1 clinical outcome. Improvements were observed regardless of baseline characteristics. Trial registration This manuscript is a post hoc analysis of data from the OSMO study. ClinicalTrials.gov, NCT02654145. Registered January 13, 2016.

Comprehensive analysis and ACMG-based classification of CHEK2 variants in hereditary cancer patients.

CHEK2 variants are associated with intermediate breast cancer risk, among other cancers. We aimed to comprehensively describe CHEK2 variants in a Spanish hereditary cancer (HC) cohort and adjust the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG-AMP) guidelines for their classification. First, three CHEK2 frequent variants were screened in a retrospective Hereditary Breast and Ovarian Cancer cohort of 516 patients. After, the whole CHEK2 coding region was analyzed by next-generation sequencing in 1848 prospective patients with HC suspicion. We refined ACMG-AMP criteria and applied different combined rules to classify CHEK2 variants and define risk alleles. We identified 10 CHEK2 null variants, 6 missense variants with discordant interpretation in ClinVar database, and 35 additional variants of unknown significance. Twelve variants were classified as (likely)-pathogenic; two can also be considered "established risk-alleles" and one as "likely risk-allele." The prevalence of (likely)-pathogenic variants in the HC cohort was 0.8% (1.3% in breast cancer patients and 1.0% in hereditary nonpolyposis colorectal cancer patients). Here, we provide ACMG adjustment guidelines to classify CHEK2 variants. We hope that this study would be useful for variant classification of other genes with low effect variants.

Long-term outcomes in chronic hypersensitivity pneumonitis.

INTRODUCTION: The objective of this study was to analyze mortality, possible predictors of long-term survival, and health-related quality of life of a large chronic hypersensitivity pneumonitis (CHP) patient sample. METHODS: Longitudinal study in patients diagnosed with CHP during 2004-2013, followed for at least 1 year. Patients remaining alive and consenting to participate had a follow-up visit during 2015, including a complete pulmonary function study and the EuroQol-5D and Beck Depression and Anxiety Inventories. RESULTS: Out of the 160 patients finally included, 87 remained alive. Seventy-three had died or underwent lung transplantation at the time of the study with a median survival of 7.0 (4.4-14.5) years. A Cox proportional risk model showed that factors associated with lower survival were as follows: increased age, a low percentage of lymphocytes in bronchoalveolar lavage (BAL), a decreased transfer factor of the lung for carbonmonoxide (DLCO), presence of honeycomb in the high-resolution chest scan (HRCT), and the usual interstitial pneumonia (UIP) histologic pattern. At follow-up, all patients presented an EuroQol-5D score <0.8 and 21(50%) and 9(28.6%) subjects presented a probable anxiety and depressive syndrome, respectively. CONCLUSION: CHP is a severe disease with a bad mid-term prognosis. Lymphocyte values in BAL and DLCO values at baseline, presence of honeycomb in HRCT, and UIP histologic pattern were found to be predictors of survival. Early accurate diagnosis of the disease is fundamental for prompt initiation of antigen avoidance.

The clinical benefit of mepolizumab replacing omalizumab in uncontrolled severe eosinophilic asthma.

BACKGROUND: Mepolizumab and omalizumab are treatments for distinct but overlapping severe asthma phenotypes. OBJECTIVE: To assess if patients eligible for both biologics but not optimally controlled with omalizumab experience improved asthma control when switched directly to mepolizumab. METHODS: OSMO was a multicenter, open-label, single-arm, 32-week trial in patients with ≥2 asthma exacerbations in the year prior to enrollment, despite receiving high-dose inhaled corticosteroids and other controller(s), plus omalizumab (≥4 months). At baseline, patients with blood eosinophil counts ≥150 cells/µL (or ≥300 cells/µL in the prior year) and an Asthma Control Questionnaire (ACQ)-5 score ≥1.5 discontinued omalizumab and immediately commenced mepolizumab 100 mg subcutaneously every 4 weeks. Endpoints included change from baseline in ACQ-5 score (primary), St George's Respiratory Questionnaire (SGRQ) score and the proportions of ACQ-5 and SGRQ responders, all at Week 32, and the annualized exacerbation rate over the study period. RESULTS: At Week 32 (intent-to-treat population [n = 145]), the least squares (LS) mean changes (standard error [SE]) in ACQ-5 and SGRQ total scores were -1.45 (0.107) and -19.0 (1.64) points; with 77% and 79% of patients achieving the minimum clinically important differences (ACQ-5: ≥0.5 points; SGRQ: ≥4 points), respectively. The annualized rate of clinically significant exacerbations was 1.18 events/year, a 64% reduction from 3.26 events/year during the previous year. Safety and immunogenicity profiles were consistent with previous trials. CONCLUSION: After directly switching from omalizumab to mepolizumab, patients with uncontrolled severe eosinophilic asthma experienced clinically significant improvements in asthma control, health status, and exacerbation rate, with no tolerability issues reported.

Immunological methods for diagnosis and monitoring of IgE-mediated allergy caused by industrial sensitizing agents (IMExAllergy).

Industrial sensitizing agents (allergens) in living and working environments play an important role in eliciting type 1 allergic disorders including asthma and allergic rhinitis. Successful management of allergic diseases necessitates identifying their specific causes (ie, identify the causative agent(s) and the route of contact to allergen: airborne, or skin contact) to avoid further exposure. Identification of sensitization by a sensitive and validated measurement of specific IgE is an important step in the diagnosis. However, only a limited number of environmental and occupational allergens are available on the market for use in sIgE testing. Accordingly, specific in-house testing by individual diagnostic and laboratory centers is often required. Currently, different immunological tests are in use at various diagnostic centers that often produce considerably divergent results, mostly due to lack of standardized allergen preparation and standardized procedures as well as inadequate quality control. Our review and meta-analysis exhibited satisfactory performance of sIgE detection test for most high molecular weight (HMW) allergens with a pooled sensitivity of 0.74 and specificity of 0.71. However, for low molecular weight (LMW) allergens, pooled sensitivity is generally lower (0.28) and specificity higher (0.89) than for HMW tests. Major recommendations based on the presented data include diagnostic use of sIgE to HMW allergens. A negative sIgE result for LMW agents does not exclude sensitization. In addition, the requirements for full transparency of the content of allergen preparations with details on standardization and quality control are underlined. Development of standard operating procedures for in-house sIgE assays, and clinical validation, centralized quality control and audits are emphasized. There is also a need for specialized laboratories to provide a custom service for the development of tests for the measurement of putative novel occupational allergens that are not commercially available.

Are high- and low-molecular-weight sensitizing agents associated with different clinical phenotypes of occupational asthma?

BACKGROUND: High-molecular-weight (HMW) proteins and low-molecular-weight (LMW) chemicals can cause occupational asthma (OA) although few studies have thoroughly compared the clinical, physiological, and inflammatory patterns associated with these different types of agents. The aim of this study was to determine whether OA induced by HMW and LMW agents shows distinct phenotypic profiles. METHODS: Clinical and functional characteristics, and markers of airway inflammation were analyzed in an international, multicenter, retrospective cohort of subjects with OA ascertained by a positive inhalation challenge response to HMW (n = 544) and LMW (n = 635) agents. RESULTS: Multivariate logistic regression analysis showed significant associations between OA caused by HMW agents and work-related rhinitis (OR [95% CI]: 4.79 [3.28-7.12]), conjunctivitis (2.13 [1.52-2.98]), atopy (1.49 [1.09-2.05]), and early asthmatic reactions (2.86 [1.98-4.16]). By contrast, OA due to LMW agents was associated with chest tightness at work (2.22 [1.59-3.03]), daily sputum (1.69 [1.19-2.38]), and late asthmatic reactions (1.52 [1.09-2.08]). Furthermore, OA caused by HMW agents showed a higher risk of airflow limitation (1.76 [1.07-2.91]), whereas OA due to LMW agents exhibited a higher risk of severe exacerbations (1.32 [1.01-1.69]). There were no differences between the two types of agents in the baseline sputum inflammatory profiles, but OA caused by HMW agents showed higher baseline blood eosinophilia and a greater postchallenge increase in fractional nitric oxide. CONCLUSION: This large cohort study describes distinct phenotypic profiles in OA caused by HMW and LMW agents. There is a need to further explore differences in underlying pathophysiological pathways and outcome after environmental interventions.

Blood eosinophils could be useful as a biomarker in chronic obstructive pulmonary disease exacerbations.

Introduction The aim of analysing the usefulness of the blood eosinophil count (BEC) as a prognostic marker in exacerbations of patients with Chronic Obstructive Pulmonary Disease (COPD), evaluating its relationship with hospital mortality, the length of stay and the early and late re-admissions. Materials and Methods We have carried out a retrospective study including all patients who required hospital admission from 1 January 2008 to 31 December 2009, with a diagnosis on hospital discharge of COPD exacerbation. These patients were classified using three cut-off points of BEC: less than 200 vs ≥ 200/µL, less than 300 vs ≥ 300/µL and less than 400 vs ≥ 400/µL. Results There were a total of 1626 hospital admissions during the study period with the diagnosis of exacerbation of COPD. In this study we have included 358 patients. The probability of any late re-admission increased with a BEC ≥ 300/µL (odds ratio: 1.684) and for those with a BEC ≥ 400/µL (odds ratio: 2.068). The BEC does not appear to be related to hospital mortality or the probability of early re-admission after an exacerbation of COPD. Conclusions In our study an elevated BEC is associated with a higher incidence of late hospital readmissions in COPD exacerbations.

Genetic variants with gene regulatory effects are associated with diisocyanate-induced asthma.

BACKGROUND: Isocyanates are major causes of occupational asthma, but susceptibility and mechanisms of diisocyanate-induced asthma (DA) remain uncertain. OBJECTIVE: The aim of this study was to identify DA-associated functional genetic variants through next-generation sequencing (NGS), bioinformatics, and functional assays. METHODS: NGS was performed in 91 workers with DA. Fourteen loci with known DA-associated single nucleotide polymorphisms (SNPs) were sequenced and compared with data from 238 unexposed subjects. Ranking of DA-associated SNPs based on their likelihood to affect gene regulatory mechanisms in the lung yielded 21 prioritized SNPs. Risk and nonrisk oligonucleotides were tested for binding of nuclear extracts from A549, BEAS-2B, and IMR-90 lung cell lines by using electrophoretic mobility shift assays. DNA constructs were cloned into a pGL3 promoter vector for luciferase gene reporter assays. RESULTS: NGS detected 130 risk variants associated with DA (3.1 × 10-6 to 6.21 × 10-4), 129 of which were located in noncoding regions. The 21 SNPs prioritized by using functional genomic data sets were in or proximal to 5 genes: cadherin 17 (CDH17; n = 10), activating transcription factor 3 (ATF3; n = 7), family with sequence similarity, member A (FAM71A; n = 2), tachykinin receptor 1 (TACR1; n = 1), and zinc finger and BTB domain-containing protein 16 (ZBTB16; n = 1). Electrophoretic mobility shift assays detected allele-dependent nuclear protein binding in A549 cells for 8 of 21 variants. In the luciferase assay 4 of the 21 SNPs exhibited allele-dependent changes in gene expression. DNA affinity precipitation and mass spectroscopy of rs147978008 revealed allele-dependent binding of H1 histones, which was confirmed by using Western blotting. CONCLUSIONS: We identified 5 DA-associated potential regulatory SNPs. Four variants exhibited effects on gene regulation (ATF rs11571537, CDH17 rs2446824 and rs2513789, and TACR1 rs2287231). A fifth variant (FAM71A rs147978008) showed nonrisk allele preferential binding to H1 histones. These results demonstrate that many DA-associated genetic variants likely act by modulating gene regulation.

Current controversies in the stepping up and stepping down of inhaled therapies for COPD at the patient level.

The implementation of potential new step-up or step-down treatment recommendations in response to current guidelines is one of the main challenges currently faced in actual daily practice settings. In the present narrative review, we aim to discuss the relevance of these step-up and step-down proposals at the patient level in daily clinical practice. In particular, we aim to review the challenges associated with inhaled maintenance therapy for chronic obstructive pulmonary disease (COPD) in four clinical scenarios. First, we discuss the step up from single to double bronchodilation, including current controversies regarding the addition of a second bronchodilator versus initial treatment with two bronchodilators. Second, we discuss the step up from double bronchodilation to triple therapy while challenging current indications for inhaled steroid therapy and discussing triple therapy designs. Third, we discuss the step down from triple therapy to double bronchodilation while evaluating the effect of this downshift in risk categories on the patient according to the new classifications. Finally, we discuss the step down from double to single bronchodilation, with a special focus on safety. We believe this review will help to highlight the most relevant discussion points regarding the treatment of COPD in a manner that will stimulate and guide related clinical research.

Specific inhalation challenge: the relationship between response, clinical variables and lung function.

INTRODUCTION: The specific inhalation challenge (SIC) is considered the gold standard for the diagnosis of occupational asthma (OA). However, its use is not standardised, and the intensity of exposure is regulated empirically. The aim of this study was to identify clinical variables and/or pulmonary function variables able to predict the scale of patients' response to SIC. MATERIAL AND METHODS: All patients who underwent SIC at our centre between 2005 and 2013 were studied. Anthropometric characteristics, atopic status, type of causal agent, latency times, pulmonary function tests and SIC results were analysed. RESULTS: Two hundred and one patients (51% men) were assessed, of whom 86 (43%) had positive SIC. In the patients with positive results, 29 (34%) were exposed to high molecular weight (HMW) agents and 57 (64%) to low molecular weight (LMW) agents. Patients with a positive SIC exposed to HMW agents had a higher fall in FEV1 after SIC compared with those exposed to LMW agents (p=0.036). The type of asthmatic reaction after SIC also differed between the groups (p=0.020). The logistic regression analysis showed that patients with a higher PC20 before SIC were less likely to have severe decreases in FEV1 after SIC after adjusting for potential confounders (OR=0.771, 95% CI 0.618 to 0.961, p=0.021). CONCLUSIONS: The scale of the response to SIC is influenced mainly by the degree of bronchial hyper-responsiveness, regardless of whether the causative agent is HMW or LMW, or whether the response is early or late.

Hypersensitivity Pneumonitis: Challenges in Diagnosis and Management, Avoiding Surgical Lung Biopsy.

This review presents an update of the currently available information related to hypersensitivity pneumonitis, with a particular focus on the contribution of several techniques in the diagnosis of this condition. The methods discussed include proper elaboration of a complete medical history, targeted auscultation, detection of specific immunoglobulin G antibodies against the most common antigens causing this disease, skin tests, antigen-specific lymphocyte activation assays, bronchoalveolar lavage, and cryobiopsy. Special emphasis is placed on the relevant contribution of specific inhalation challenge (bronchial challenge test). Surgical lung biopsy is presented as the ultimate recourse, to be used when the diagnosis cannot be reached through the other methods covered.