Exploring CD26-/lo subpopulations of lymphocytes in asthma phenotype and severity: A novel CD4+ T cell subset expressing archetypical granulocyte proteins.

BACKGROUND: Asthma pathology may induce changes in naïve/memory lymphocyte proportions assessable through the evaluation of surface CD26 (dipeptidyl peptidase 4/DPP4) levels. Our aim was to investigate the association of asthma phenotype/severity with the relative frequency of CD26-/lo, CD26int and CD26hi subsets within different lymphocyte populations. METHODS: The proportion of CD26-/lo, CD26int and CD26hi subsets within CD4+ effector T cells (Teff), total CD4- lymphocytes, γδ-T cells, NK cells and NKT cells was measured in peripheral blood samples from healthy (N = 30) and asthma (N = 119) donors with different phenotypes/severities by flow cytometry. We performed K-means clustering analysis and further characterised the CD4+CD26-/lo Teff cell subset by LC-MS/MS and immunofluorescence. RESULTS: Cluster analysis including clinical and flow cytometry data resulted in four groups, two of them with opposite inflammatory profiles (neutrophilic vs. eosinophilic). Neutrophilic asthma presented reduced CD4-CD26hi cells, which negatively correlated with systemic inflammation. Eosinophilic asthma displayed a general expansion of CD26-/lo subsets. Specifically, CD4+CD26-/lo Teff expansion was confirmed in asthma, especially in atopic patients. Proteomic characterisation of this subset with a TEM/TEMRA phenotype revealed upregulated levels of innate (e.g. MPO and RNASE2) and cytoskeleton/extracellular matrix (e.g. MMP9 and ACTN1) proteins. Immunofluorescence assays confirmed the presence of atypical proteins for CD4+ T cells, and an enrichment in 'flower-like' nuclei and MMP9/RNASE2 levels in CD4+CD26-/lo Teff compared to CD4+ T lymphocytes. CONCLUSION: There is an association between CD26 levels in different lymphocyte subsets and asthma phenotype/severity. CD4+CD26-/loTEMRA cells expressing innate proteins specific to eosinophils/neutrophils could be determinant in sustaining long-term inflammation in adult allergic asthma.

Serum exosome inflamma-miRs are surrogate biomarkers for asthma phenotype and severity.

BACKGROUND: Asthma is a heterogeneous disease with several phenotypes, endotypes and severity degrees, in which different T-cell subpopulations are involved. These cells express specific miRNAs (i.e. inflamma-miRs) that can be released to serum in exosomes after activation and be used as biomarkers of underlying inflammation. Thus, we aim to evaluate specific T-cell miRNA signatures in serum exosomes from different subgroups of asthmatic patients. METHODS: Samples from healthy donors (N = 30) and patients (N = 119) with different asthma endotypes (T2high -Atopic/T2high -Non-atopic/T2low ) and severity degrees (mild/MA and moderate-severe/MSA) were used. Demographic, clinical, haematological and biochemical characteristics were collected. Twelve miRNAs previously associated with different Th subsets were preselected and their levels in serum exosome samples were measured using RTqPCR. RESULTS: We detected five miRNAs with high confidence in serum exosomes: miR-16-5p, miR-21-5p, miR-126-3p, miR146a-5p and miR-215-5p. All of them, except miR-16-5p were upregulated in MSA patients compared to MA. A logistic regression model including each of these miRNAs was created to discriminate both conditions, rendering a ROC curve AUC of 0.896 (0.830-0.961). miR-21-5p and miR-126-3p, both involved in Th1/Th2 differentiation, were specifically augmented in T2high -Atopic patients. Of note, all these changes were found in samples collected in autumn. On the contrary, IL-6high patients with MSA, which were more obese, older, with higher neutrophil and basophil counts and TNF levels, displayed a decrease of miR-21-5p, miR-126-3p and miR-146a-5p. CONCLUSION: Immune-related miRNAs, including miR-21-5p, miR-126-3p, miR-146a-5p and miR-215-5p, can be used as clinically relevant non-invasive biomarkers of the phenotype/endotype and severity of asthma.

Impact of anxiety and depression on the prognosis of copd exacerbations.

BACKGROUND: Frequent and highly prevalent as comorbidities in Chronic Obstructive Pulmonary Disease (COPD) patients, both depression and anxiety seem to have an impact on COPD prognosis. However, they are underdiagnosed and rarely treated properly. AIM: To establish the prevalence of depression and anxiety in patients admitted for Acute Exacerbation of COPD (AECOPD) and determine their influence on COPD prognosis. METHODS: Prospective observational study conducted from October 1, 2016 to October 1, 2018 at the following centers in Galicia, Spain: Salnés County Hospital, Arquitecto Marcide, and Clinic Hospital Complex of Santiago de Compostela. Patients admitted for AECOPD who agreed to participate and completed the anxiety and depression scale (HADS) were included in the study. RESULTS: 288 patients (46.8%) were included, mean age was 73.7 years (SD 10.9), 84.7% were male. 67.7% patients were diagnosed with probable depression, and depression was established in 41.7%; anxiety was probable in 68.2% and established in 35.4%. 60.4% of all patients showed symptoms of both anxiety and depression. Multivariate analysis relates established depression with a higher risk of late readmission (OR 2.06, 95% CI 1.28; 3.31) and a lower risk of mortality at 18 months (OR 0.57, 95% CI 0.37; 0.90). CONCLUSION: The prevalence of anxiety and depression in COPD patients is high. Depression seems to be an independent factor for AECOPD, so early detection and a multidisciplinary approach could improve the prognosis of both entities. The study was approved by the Ethical Committee of Galicia (code 2016/460).

iTRAQ-based proteomic analysis reveals potential serum biomarkers of allergic and nonallergic asthma.

BACKGROUND: Asthma is heterogeneous disease with different phenotypes, endotypes and severities. Definition of these subgroups requires the identification of biomarkers in biological samples, and serum proteomics is a useful and minimally invasive method for this purpose. Therefore, the aim of this study was to detect serum proteins whose abundance is distinctively associated with different asthma phenotypes (allergic vs nonallergic) or severities. METHODS: For each group of donors (32 healthy controls, 43 allergic rhinitis patients and 192 asthmatics with different phenotypes and severities), we generated two pools of sera that were analysed by a shotgun MS approach based on combinatorial peptide ligand libraries and iTRAQ-LC-MS/MS. RESULTS: MS analyses identified 18 proteins with a differential abundance. Functional/network study of these proteins identified key processes for asthma pathogenesis, such as complement activation, extracellular matrix organization, platelet activation and degranulation, or post-translational protein phosphorylation. Furthermore, our results highlighted an enrichment of the "Regulation of Insulin-like Growth Factor (IGF) transport and uptake by Insulin-like Growth Factor Binding Proteins (IGFBPs)" route in allergic asthma and the lectin pathway of complement activation in nonallergic asthma. Thus, several proteins (eg IGFALS, HSPG2, FCN2 or MASP1) displayed a differential abundance between the different groups of donors. Particularly, our results revealed IGFALS as a useful biomarker for moderate-severe allergic asthma. CONCLUSION: Our data suggest a set of serum biomarkers, especially IGFALS, capable of differentiating allergic from nonallergic asthma. These proteins reveal different pathophysiological mechanisms and may be useful in the future for diagnosis, prognosis or targeted therapy purposes.

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.

The association between paracetamol and asthma is still under debate.

OBJECTIVE: To analyse the relationship between paracetamol and asthma. DATA SOURCES: An English literature search using electronic search engines (PubMed and EMBASE) was conducted. STUDY SELECTIONS: Articles published in peer-review journals, from 1990 to December 2015 were included. To perform the search for the most suitable and representative articles, keywords were selected ("asthma," "paracetamol" and "acetaminophen"). The evidence level was rated according to the criteria of the Oxford Centre For Evidence-Based Medicine. RESULTS: The exposure to paracetamol during pregnancy was analysed in several cohort studies, showing an association between the prenatal exposure to paracetamol with suffering from asthma or presence of wheezing in childhood, especially for persistent wheezing. Nevertheless, a recent study concluded that the relationship between asthma and paracetamol is explained, at least in part, by confounding factors. Several works have also associated the exposure to paracetamol in the first years of life or in adults with the development of childhood asthma. Several pathophysiological mechanisms are known that could explain this relationship, such as the glutathione pathway, the decrease in the release of Th1 cytokines that are normally produced during febrile episodes, which would then lead to a predominance of Th2 cytokines, the cytotoxic effect of paracetamol for pneumocytes, a modulator effect on the activity of myeloperoxidase, as well as the possible antigenic effect of paracetamol, mediated by IgE. CONCLUSIONS: There are many arguments that suggest a relationship between the use of paracetamol with the appearance of asthmatic symptoms, however the evidence is inconclusive.

Identification of Asthma Phenotypes in the Spanish MEGA Cohort Study Using Cluster Analysis.

INTRODUCTION: The definition of asthma phenotypes has not been fully established, neither there are cluster studies showing homogeneous results to solidly establish clear phenotypes. The purpose of this study was to develop a classification algorithm based on unsupervised cluster analysis, identifying clusters that represent clinically relevant asthma phenotypes that may share asthma-related outcomes. METHODS: We performed a multicentre prospective cohort study, including adult patients with asthma (N=512) from the MEGA study (Mechanisms underlying the Genesis and evolution of Asthma). A standardised clinical history was completed for each patient. Cluster analysis was performed using the kernel k-groups algorithm. RESULTS: Four clusters were identified. Cluster 1 (31.5% of subjects) includes adult-onset atopic patients with better lung function, lower BMI, good asthma control, low ICS dose, and few exacerbations. Cluster 2 (23.6%) is made of adolescent-onset atopic asthma patients with normal lung function, but low adherence to treatment (59% well-controlled) and smokers (48%). Cluster 3 (17.1%) includes adult-onset patients, mostly severe non-atopic, with overweight, the worse lung function and asthma control, and receiving combination of treatments. Cluster 4 (26.7%) consists of the elderly-onset patients, mostly female, atopic (64%), with high BMI and normal lung function, prevalence of smokers and comorbidities. CONCLUSION: We defined four phenotypes of asthma using unsupervised cluster analysis. These clusters are clinically relevant and differ from each other as regards FEV1, age of onset, age, BMI, atopy, asthma severity, exacerbations, control, social class, smoking and nasal polyps.

The polyhedric reality of the interaction between COVID-19, asthma and inhaled corticosteroids.

The impact of ICS on the prognosis for #COVID19 in #asthma patients requires a thorough evaluation of a range of factors that interact in this process, in order to draw solid conclusions, since at the present time the debate continues https://bit.ly/3xLNBrc.

Risk Factors of Mortality in Hospitalized Patients With COVID-19 Applying a Machine Learning Algorithm.

Introduction: Risk stratification of patients with COVID-19 can be fundamental to support clinical decision-making and optimize resources. The objective of our study is to identify among the routinely tested clinical and analytical parameters those that would allow us to determine patients with the highest risk of dying from COVID-19. Material and methods: We carried out a retrospective cohort multicentric study by consecutively, including hospitalized patients with COVID-19 admitted in any of the 11 hospitals in the healthcare network of HM Hospitals-Spain. We collected the clinical, demographic, analytical, and radiological data from the patient's medical records.To assess each of the biomarkers' predictive impact and measure the statistical significance of the variables involved in the analysis, we applied a random forest with a permutation method. We used the similarity measure induced by a previously classification model and adjusted the k-groups clustering algorithm based on the energy distance to stratify patients into a high and low-risk group. Finally, we adjusted two optimal classification trees to have a schematic representation of the cut-off points. Results: We included 1246 patients (average age of 65.36 years, 62% males). During the study one hundred sixty-eight patients (13%) died. High values of age, D-Dimer, White Blood Cell, Na, CRP, and creatinine represent the factors that identify high-risk patients who would die. Conclusions: Age seems to be the primary predictor of mortality in patients with SARS-CoV-2 infection, while the impact of acute phase reactants and blood cellularity is also highly relevant.

Introducción: La estratificación del riesgo de los pacientes con COVID-19 puede ser fundamental para apoyar la toma de decisiones clínicas y optimizar los recursos. El objetivo de nuestro estudio es identificar, entre los parámetros clínicos y analíticos probados de forma rutinaria, aquellos que nos permitirían determinar a los pacientes con mayor riesgo de morir por COVID-19. Material y métodos: Se realizó un estudio multicéntrico de cohorte retrospectiva de forma consecutiva, incluyendo pacientes hospitalizados con COVID-19 ingresados en cualquiera de los 11 hospitales de la red sanitaria de HM Hospitales-España.Los datos clínicos, demográficos, analíticos y radiológicos se recopilaron de las historias clínicas de los pacientes.Para evaluar el impacto predictivo de cada uno de los biomarcadores y medir la significación estadística de las variables involucradas en el análisis, se aplicó un bosque aleatorio con un método de permutación. Utilizamos la medida de similitud inducida por un modelo de clasificación previo, y ajustamos el algoritmo de agrupación de grupos k en función de la distancia de energía para estratificar a los pacientes en un grupo de alto y bajo riesgo. Finalmente, ajustamos 2 árboles de clasificación óptimos para tener una representación esquemática de los puntos de corte. Resultados: Se incluyeron 1.246 pacientes (edad promedio de 65,36 años, 62% varones). Durante el estudio murieron 168 pacientes (13%). Los factores que identifican a los pacientes de alto riesgo de mortalidad son los valores elevados de edad, dímero D, glóbulos blancos, Na, PCR y creatinina. Conclusiones: La edad parece ser el principal predictor de mortalidad en pacientes con infección por SARS-CoV-2, mientras que el impacto de los reactantes de fase aguda y la celularidad sanguínea también es muy relevante.

Association of rhinitis with asthma prevalence and severity.

Asthma and rhinitis often co-exist in the same patient. Although some authors observed a higher prevalence and/or greater severity of asthma in patients with rhinitis, this view is not homogeneous and the debate continues. The aim of our study is to describe the prevalence of rhinitis in children and adolescents and to analyse their relationship with the prevalence of asthma. A multicentre study was conducted using the methodology of the International Study of Asthma and Allergies in Childhood (ISAAC). The target population of the study was all those school children aged 6-7 and 13-14 years from 6 of the main health catchment areas of Galicia (1.9 million inhabitants). The schools required were randomly selected, and all children in the targeted age ranges were included. Multiple logistic regression was used to obtain adjusted prevalence odds ratios (OR) between asthma symptoms of the schoolchildren and rhinitis prevalence. The results were adjusted for parental smoking habits, maternal education level, cat and dog exposure, and obesity. A total of 21,420 valid questionnaires were finally obtained. Rhinitis was associated with a significant increase in the prevalence of asthma in both age groups. The highest OR were 11.375 for exercise induced asthma (EIA) for children with recent rhinoconjunctivitis and 9.807 for children with recent rhinitis in 6-7 years old group. The prevalence OR's are higher in EIA and severe asthmatics. Rhinitis in children and adolescents is associated with a higher prevalence and severity of asthma.

Variability of blood eosinophil count and prognosis of COPD exacerbations.

BACKGROUND: Eosinophils in peripheral blood are one of the emerging biomarkers in chronic obstructive pulmonary disease (COPD) patients. However, when analysing the relationship between peripheral eosinophilia and COPD prognosis, highly variable results are obtained. The aim of our study is to describe the serum eosinophilia levels in COPD patients and to analyse their relationship to prognosis following hospital admission. METHODS: A prospective observational study was conducted from 1 October 2016 to 1 October 2018 in the following Spanish centres: Salnés County Hospital in Vilagarcía de Arousa, Arquitecto Marcide Hospital in Ferrol and the University Hospital Complex in Santiago de Compostela. The patients were classified using three cut-off points of blood eosinophil count (BEC): 150 cells/µL, 300 cells/µL, and 400 cells/µL; in addition, the peripheral BEC was analysed on admission. RESULTS: 615 patients were included in the study, 86.2% male, mean age 73.9 years, and mean FEV1 52.7%. The mean stay was 8.4 days, and 6% of all patients were readmitted early. No significant relationship was observed between the BEC, neither in the stable phase nor in the acute phase, and hospital stay, readmissions, deaths during admission, the need for intensive care, or the condition of frequent exacerbator. CONCLUSION: The results of our study do not seem to support the usefulness of BEC as a COPD biomarker.KEY MESSAGESThere is evidence that BEC participates in pathophysiological mechanisms of the COPD.BEC may be useful as a biomarker in COPD for aspects such as the optimization of treatments.We did not find any relationship between BEC levels and prognosis following hospital admission for AECOPD.

Clinical and inflammatory characteristics of patients with asthma in the Spanish MEGA project cohort.

INTRODUCTION: The MEGA (MEchanism underlying the Genesis and evolution of Asthma) project is a multicenter cohort study carried out in eight Spanish hospitals, gathering clinical, physiological, and molecular data from patients with asthma and multimorbidities in order to gain insight into the different physiopathological mechanisms involved in this disorder. MATERIAL AND METHODS: We report the baseline clinical and physiological characteristics and biomarker measures of adult participants in the project with the aim of better understanding the natural history and underlying mechanisms of asthma as well as the associated multimorbidities across different levels of severity. We carried out a detailed clinical examination, pulmonary function testing, measurement of fractional exhaled nitric oxide (FeNO), blood counts, induced sputum, skin prick tests, chest computed tomography scan, asthma questionnaires, and multimorbidity assessment in 512 asthmatic patients. RESULTS: When compared to patients with milder disease, severe asthmatic patients showed greater presence of symptoms, more exacerbations, lower asthma control, increased airflow obstruction, and higher frequency of chronic rhinosinusitis with nasal polyps, severe rhinitis, anxiety and depression, gastroesophageal reflux, and bronchiectasis. CONCLUSION: The MEGA project succeeded in recruiting a high number of asthma patients, especially those with severe disease, who showed lower control and higher frequency of multimorbidities.

Obesity Does Not Increase the Risk of Asthma Readmissions.

The relationship between obesity and asthma exacerbations is still under debate. The aim of our work is to analyse the relationship between obesity and hospital re-admissions in asthmatics. A review was retrospectively performed on all hospital admissions of adult patients due to asthma exacerbation occurring in our hospital for 11 years. All those cases with asthma as the first diagnosis in the discharge report were included, or those with asthma as the second diagnosis provided when the first diagnosis was respiratory infection or respiratory failure. Only the first hospital admission of each patient was included in this study. The Odds Ratios of a higher incidence of early/late readmissions due to asthma exacerbation were calculated using a binary logistic regression, using the body mass index (BMI) as independent variable, adjusted for all the variables included in the study. The study included 809 patients with a mean age of 55.6 years, and 65.2% were female. The majority (71.4%) were obese or overweight. No significant relationship was observed in the univariate or multivariate analyses between overweight or obesity and the early or late hospital readmissions due to asthma. Therefore, obesity does not seem to be a determining factor in the risk of asthma exacerbations.

Expansion of different subpopulations of CD26-/low T cells in allergic and non-allergic asthmatics.

CD26 displays variable levels between effector (TH17 ≫ TH1 > TH2 > Treg) and naïve/memory (memory > naïve) CD4+ T lymphocytes. Besides, IL-6/IL-6R is associated with TH17-differentiation and asthma severity. Allergic/atopic asthma (AA) is dominated by TH2 responses, while TH17 immunity might either modulate the TH2-dependent inflammation in AA or be an important mechanism boosting non-allergic asthma (NAA). Therefore, in this work we have compared the expression of CD26 and CD126 (IL-6Rα) in lymphocytes from different groups of donors: allergic (AA) and non-allergic (NAA) asthma, rhinitis, and healthy subjects. For this purpose, flow cytometry, haematological/biochemical, and in vitro proliferation assays were performed. Our results show a strong CD26-CD126 correlation and an over-representation of CD26- subsets with a highly-differentiated effector phenotype in AA (CD4+CD26-/low T cells) and NAA (CD4-CD26- γδ-T cells). In addition, we found that circulating levels of CD26 (sCD26) were reduced in both AA and NAA, while loss of CD126 expression on different leukocytes correlated with higher disease severity. Finally, selective inhibition of CD26-mRNA translation led to enhanced T cell proliferation in vitro. These findings support that CD26 down-modulation could play a role in facilitating the expansion of highly-differentiated effector T cell subsets in asthma.

Association between blood eosinophil count with asthma hospital readmissions.

INTRODUCTION: The presence of eosinophils in asthma inflammation is a relevant factor in the pathophysiology of the disease, however the relationship between the blood eosinophil count (BEC) with asthma severity and prognosis is still under debate. The aim of this work is to analyze the relationship between the BEC levels and hospital readmissions in patients with asthma. MATERIAL AND METHODS: A review was retrospectively carried out on all admissions of patients over 18 years old due to exacerbation of asthma occurring in our hospital between the years 2000 and 2010. The personal characteristics and the asthma personal history of each patient were recorded. The BEC was determined from the first blood sample taken from the patient after their arrival at the hospital. Hospital early, late and frequent readmissions were analyzed using 4 cut-off points; less than 150 eosinophils/µL vs ≥150/µL, less than 200 vs 200 /µL, less than 300 vs ≥300/µL, and less than 400 vs ≥400/µL. RESULTS: We have included 1316 patients, 70% of whom are women, as well as a mean age of 60 years, and a mean FEV1 of 73.5% of the reference value. The mean eosinophil blood count was 201.7 cells/µL. A BEC ≥300 cells/µL showed a reduction of risk of late readmission of 42%, a BEC ≥400 cells/µL showed a reduction in late readmission risk of 41% and decrease in frequent late readmission of 63%. CONCLUSIONS: Our study appears to support that an elevated BEC is associated with a lower incidence of asthma hospital readmissions.

The MEGA Project: A Study of the Mechanisms Involved in the Genesis and Disease Course of Asthma. Asthma Cohort Creation and Long-Term Follow-Up. / Estudio de los mecanismos implicados en la génesis y evolución del asma (proyecto MEGA): creación y seguimiento a largo plazo de una cohorte de pacientes asmáticos.

The general aim of this study is to create a cohort of asthma patients with varying grades of severity in order to gain greater insight into the mechanisms underlying the genesis and course of this disease. The specific objectives focus on various studies, including imaging, lung function, inflammation, and bronchial hyperresponsiveness, to determine the relevant events that characterize the asthma population, the long-term parameters that can determine changes in the severity of patients, and the treatments that influence disease progression. The study will also seek to identify the causes of exacerbations and how this affects the course of the disease. Patients will be contacted via the outpatient clinics of the 8 participating institutions under the auspices of the Spanish Respiratory Diseases Networking System (CIBER). In the inclusion visit, a standardized clinical history will be obtained, a clinical examination, including blood pressure, body mass index, complete respiratory function tests, and FENO will be performed, and the Asthma Control Test (ACT), Morisky-Green test, Asthma Quality of Life Questionnaire (Mini AQLQ), the Sino-Nasal Outcome Test 22 (SNOT-22), and the Hospital Anxiety and Depression scale (HADS) will be administered. A specific electronic database has been designed for data collection. Exhaled breath condensate, urine and blood samples will also be collected. Non-specific bronchial hyperresponsiveness testing with methacholine will be performed and an induced sputum sample will be collected at the beginning of the study and every 24 months. A skin prick test for airborne allergens and a chest CT will be performed at the beginning of the study and repeated every 5 years.