Serum biomarkers in elderly asthma

Management of eosinophil-associated inflammatory diseases: the importance of a multidisciplinary approach

Elevated eosinophil counts in blood and tissue are a feature of many pathological processes. Eosinophils can migrate and accumulate in a wide variety of tissues and, by infiltrating a target organ, can mediate the development of several inflammatory diseases. The normalization of eosinophilia is a common biomarker of a treatable trait and can also be used as a prognostic and predictive biomarker since it implies a reduction in type 2 inflammation that contributes to disease pathogenesis. Biological therapies targeting this cell type and its proinflammatory mediators have been shown to be effective in the management of a number of eosinophilic diseases, and for this reason they constitute a potential common strategy in the treatment of patients with various multimorbidities that present with type 2 inflammation. Various biological options are available that could be used to simultaneously treat multiple target organs with a single drug, bearing in mind the need to offer personalized treatments under the umbrella of precision medicine in all patients with eosinophil-associated diseases (EADs). In addition to reviewing these issues, we also discuss a series of perspectives addressing the management of EAD patients from a multidisciplinary approach, with the collaboration of health professionals from different specialties who manage the different multimorbidities that frequently occur in these patients. We examine the basic principles of care that this multidisciplinary approach must cover and present a multidisciplinary expert opinion regarding the ideal management of patients with EADs, from diagnosis to therapeutic approach and follow-up.

Quantitative proteomics profiling of plasma from children with asthma

A lack of validated blood diagnostic markers presents an obstacle to asthma control. The present study sought to profile the plasma proteins of children with asthma and to determine potential biomarkers. Plasma samples from children in acute exacerbation (n = 4), in clinical remission (n = 4), and from healthy children (n = 4, control) were analyzed using a tandem mass tag (TMT)-labeling quantitative proteomics and the candidate biomarkers were validated using liquid chromatography-parallel reaction monitoring (PRM)/mass spectrometry (MS) with enzyme-linked immunosorbent assay (ELISA). We identified 347 proteins with differential expression between groups: 125 (50 upregulated, 75 downregulated) between acute exacerbation and control, 142 (72 upregulated, 70 downregulated) between clinical remission and control, and 55 (22 upregulated, 33 downregulated) between acute and remission groups (all between-group fold changes > 1.2; P < 0.05 by Student's t-test). Gene ontology analysis implicated differentially expressed proteins among children with asthma in immune response, the extracellular region, and protein binding. Further, KEGG pathway analysis of differentially expressed proteins identified complement and coagulation cascades and Staphylococcus aureus infection pathways as having the highest protein aggregation. Our analyses of protein interactions identified important node proteins, particularly KRT10. Among 11 differentially expressed proteins, seven proteins (IgHD, IgHG4, AACT, IgHA1, SAA, HBB, and HBA1) were verified through PRM/MS. Protein levels of AACT, IgA, SAA, and HBB were verified through ELISA and may be useful as biomarkers to identify individuals with asthma. In conclusion, our study presents a novel comprehensive analysis of changes in plasma proteins in children with asthma and identifies a panel for accessory diagnosis of pediatric asthma.

Characteristics of older adult hospitalized patients with bronchial asthma: a retrospective study

Background

Bronchial asthma is a chronic inflammation of the airways. Older adult patients with bronchial asthma are defined as patients older than 65 and with a previous or current clear diagnosis of asthma. The purpose of this study was to determine the characteristics of older adult hospitalized patients with bronchial asthma.

Methods

We retrospectively analyzed the data from patients with bronchial asthma admitted to the General Hospital of the Northern Theater Command from September 2018 to January 2020. We divided them into the older adult (≥ 65 years) and the younger (< 65 years) groups. We compared the clinical and epidemiological characteristics of the two groups.

Results

There were 181 inpatients with bronchial asthma, including 41 older adult patients, accounting for 22.7%. There were significant differences in age, sex, smoking, duration of disease, age at diagnosis of asthma, hospital stays, hospitalization costs, number of acute attacks 1 year before admission, number of hospitalizations in our hospital one year before admission, asthma control test score, forced expiratory volume in 1 s (FEV1), FEV1/FVC, the severity of acute attacks, comorbidities, and inhaled corticosteroid dose between the two groups. There were many older adult patients with asthma (mostly late-onset asthma). The hospitalization costs were high. Most patients had many comorbidities, poor asthma control, severe attack, and heavy economic burdens.

Conclusion

Attention should be focused on achieving asthma control in older adult patients to improve their quality of life and reduce their economic burdens.

Blood eosinophil cationic protein and eosinophil-derived neurotoxin are associated with different asthma expression and evolution in adults

BACKGROUND

Eosinophil-derived neurotoxin (EDN) and eosinophil cationic protein (ECP) are proteins released by activated eosinophils whose role in adult asthma remains unclear.

OBJECTIVE

To study associations between ECP, EDN and various asthma characteristics in adults from the Epidemiological Study on the Genetics and Environment of Asthma (EGEA).

METHODS

Plasma ECP and EDN levels were measured by ELISA. Cross-sectional analyses were performed in 941 adults (43±16 years old, 39% with asthma) at EGEA2 (2003-2007). Longitudinal analyses investigated the associations between EDN level at EGEA2 and changes in asthma characteristics between EGEA2 and EGEA3 (2011-2013, n=817). We used generalised estimated equations adjusted for age, sex, smoking status and body mass index to take into account familial dependence.

RESULTS

At EGEA2, both high ECP and EDN levels were associated with current asthma (adjusted OR (aOR) (95% CI): 1.69 (1.35-2.12) and 2.12 (1.76-2.57)). Among asthmatics, high EDN level was associated with asthma attacks (aOR: 1.50 (1.13-1.99)), wheezing and breathlessness (aOR: 1.38 (1.05-1.80)), use of asthma treatments (aOR: 1.91 (1.37-2.68)) and bronchial hyper-responsiveness (aOR: 2.03 (1.38-2.97)), even after further adjustment on ECP. High ECP level was associated with high neutrophil count and tended to be associated with chronic bronchitis. High EDN level at EGEA2 was associated with persistent asthma (aOR: 1.62 (1.04-2.52)), nocturnal symptoms (aOR from 2.19 to 3.57), worsening wheezing and breathlessness (aOR: 1.97 (1.36-2.85)) and nocturnal shortness of breath (aOR: 1.44 (1.04-1.98)) between EGEA2 and EGEA3.

CONCLUSIONS

EDN and ECP were associated with different asthma expression in adults. EDN could be a potential biomarker to monitor asthma evolution in adults.

Metabolic Phenotypes in Asthmatic Adults: Relationship with Inflammatory and Clinical Phenotypes and Prognostic Implications

Bronchial asthma is a chronic disease that affects individuals of all ages. It has a high prevalence and is associated with high morbidity and considerable levels of mortality. However, asthma is not a single disease, and multiple subtypes or phenotypes (clinical, inflammatory or combinations thereof) can be detected, namely in aggregated clusters. Most studies have characterised asthma phenotypes and clusters of phenotypes using mainly clinical and inflammatory parameters. These studies are important because they may have clinical and prognostic implications and may also help to tailor personalised treatment approaches. In addition, various metabolomics studies have helped to further define the metabolic features of asthma, using electronic noses or targeted and untargeted approaches. Besides discriminating between asthma and a healthy state, metabolomics can detect the metabolic signatures associated with some asthma subtypes, namely eosinophilic and non-eosinophilic phenotypes or the obese asthma phenotype, and this may prove very useful in point-of-care application. Furthermore, metabolomics also discriminates between asthma and other “phenotypes” of chronic obstructive airway diseases, such as chronic obstructive pulmonary disease (COPD) or Asthma–COPD Overlap (ACO). However, there are still various aspects that need to be more thoroughly investigated in the context of asthma phenotypes in adequately designed, homogeneous, multicentre studies, using adequate tools and integrating metabolomics into a multiple-level approach.

New mAbs facilitate quantification of secreted equine TNF-α and flow cytometric analysis in monocytes and T cells

Tumor necrosis factor-α (TNF-α) is a pleiotropic cytokine, that is involved in acute inflammation and is employed as a biomarker of inflammatory diseases in several species for which reliable quantification is available. We aimed to develop suitable tools to quantify TNF-α in equine samples. We generated two new mAbs against equine TNF-α (clones 48 and 292), evaluated their specificity for this cytokine, and confirmed detection of native TNF-α in stimulated equine PBMC. The TNF-α mAbs were paired in a fluorescent bead-based assay for quantification of equine TNF-α. The TNF-α assay had a wide quantification range of 12 pg/mL - 38.4 ng/mL. In addition, TNF-α mAb 48 was used for a detailed analysis of TNF-α production in PBMC by intracellular staining and flow cytometry. TNF-α was expressed by CD14⁺ monocytes after LPS stimulation and by monocytes and lymphocytes after polyclonal stimulation with PMA and ionomycin in vitro. TNF-α expressing lymphocytes consisted mainly of CD4⁺ T cells. CD8⁺ T cells and other lymphocytes also expressed TNF-α. The new mAbs evaluated here for soluble and intracellular TNF-α will enable the detailed analysis of this important pro-inflammatory cytokine during equine immune responses and inflammatory diseases of the horse.

IgE Downregulates PTEN through MicroRNA-21-5p and Stimulates Airway Smooth Muscle Cell Remodeling

The patho-mechanism leading to airway wall remodeling in allergic asthma is not well understood and remodeling is resistant to therapies. This study assessed the effect of immunoglobulin E (IgE) in the absence of allergens on human primary airway smooth muscle cell (ASMC) remodeling in vitro. ASMCs were obtained from five allergic asthma patients and five controls. Proliferation was determined by direct cell counts, mitochondrial activity by expression of cytochrome c, protein expression by immunoblotting and immuno-fluorescence, cell migration by microscopy imaging, and collagen deposition by cell based ELISA and RNA expression by real time PCR. Non-immune IgE activated two signaling pathways: (i) signal transducer and activator of transcription 3 (STAT3)→miR-21-5p→downregulating phosphatase and tensin homolog (PTEN) expression, and (ii) phosphatidylinositol 3-kinases (PI3K)→protein kinase B (Akt)→mammalian target of rapamycin (mTOR)→ribosomal protein S6 kinase beta-1 (p70s6k)→peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC1-α)→peroxisome proliferator-activated receptor-γ (PPAR-γ)→cyclooxygenase-2 (COX-2)→mitochondrial activity, proliferation, migration, and extracellular matrix deposition. Reduced PTEN expression correlated with enhanced PI3K signaling, which upregulated ASMC remodeling. The inhibition of microRNA-21-5p increased PTEN and reduced mTOR signaling and remodeling. Mimics of microRNA-21-5p had opposing effects. IgE induced ASMC remodeling was significantly reduced by inhibition of mTOR or STAT3. In conclusion, non-immune IgE alone is sufficient for stimulated ASMC remodeling by upregulating microRNA-21-5p. Our findings suggest that the suppression of micoRNA-21-5p may present a therapeutic target to reduce airway wall remodeling.

Blood biomarkers in chronic airways diseases and their role in diagnosis and management

INTRODUCTION

The complexity and heterogeneous nature of asthma and chronic obstructive pulmonary disease (COPD) results in difficulties in diagnosing and treating patients. Biomarkers that can identify underlying mechanisms, identify patient phenotypes and to predict treatment response could be of great value for adequate treatment. Areas covered: Biomarkers play an important role for the development of novel targeted therapies in airways disease. Blood biomarkers are relatively non-invasive, easy to obtain and easy to apply in routine care. Several blood biomarkers are being used to diagnose and monitor chronic airways diseases, as well as to predict response to treatment and long-term prognosis. Blood eosinophils are the best studied biomarker, the most applied in clinical practice, and until now the most promising of all blood biomarkers. Other blood biomarkers, including serum periostin, IgE and ECP and plasma fibrinogen are less studied and less relevant in clinical practice. Recent developments include the use of antibody assays of many different cytokines at the same time, and 'omics' techniques and systems medicine. Expert commentary: With the exception of blood eosinophils, the use of blood biomarkers in asthma and COPD has been rather disappointing. Future research using new technologies like big-data analysis of blood samples from real-life patient cohorts will probably gain better insight into underlying mechanisms of different disease phenotypes. Identification of specific molecular pathways and associated biomarkers will then allow the development of new targets for precision medicine.

Eosinophilic and Neutrophilic Airway Inflammation in the Phenotyping of Mild-to-Moderate Asthma and Chronic Obstructive Pulmonary Disease

Asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous diseases with different inflammatory phenotypes. Various inflammatory mediators play a role in these diseases. The aim of this study was to analyze the neutrophilic and eosinophilic airway and systemic inflammation as the phenotypic characterization of patients with asthma and COPD. Twenty-four patients with asthma and 33 patients with COPD were enrolled in the study. All the patients were in mild-to-moderate stage of disease, and none of them were treated with inhaled corticosteroids. Concentrations of IL-6, neutrophil elastase (NE), matrix metalloproteinase 9 (MMP-9), eosinophil cationic protein (ECP), and IL-33 and IL-17 in serum and induced sputum (IS) were measured by enzyme-linked immunosorbent assay (ELISA). The cellular composition of blood and IS was evaluated. Hierarchical clustering of patients was performed for the combination of selected clinical features and mediators. Asthma and COPD can be differentiated based on eosinophilic/neutrophilic systemic or airway inflammation with unsatisfactory efficiency. Hierarchical clustering of patients based on blood eosinophil percentage and clinical data revealed two asthma clusters differing in the number of positive skin prick tests and one COPD cluster with two subclusters characterized by low and high blood eosinophil concentrations. Clustering of patients according to IS measurements and clinical data showed two main clusters: pure asthma characterized by high eosinophil/atopy status and mixed asthma and COPD cluster with low eosinophil/atopy status. The neutrophilic phenotype of COPD was associated with more severe airway obstruction and hyperinflation.

Characterization and redox mechanism of asthma in the elderly

Asthma is a chronic disease characterized by reversible airflow limitation, coughing, bronchial constriction, and an inflammatory immune response. While asthma has frequently been categorized as emerging in childhood, evidence has begun to reveal that the elderly population is certainly susceptible to late-onset, or even long-standing asthma. Non-atopic asthma, most commonly found in elderly patients is associated with elevated levels of serum and sputum neutrophils and may be more detrimental than atopic asthma. The mortality of asthma is high in the elderly since these patients often possess more severe symptoms than younger populations. The redox mechanisms that mediate inflammatory reactions during asthma have not been thoroughly interpreted in the context of aging. Thus, we review the asthmatic symptoms related to reactive oxygen species (ROS) and reactive nitrogen species (RNS) in seniors. Moreover, immune status in the elderly is weakened in part by immunosenescence, which is broadly defined as the decline in functionality of the immune system that corresponds with increasing age. The effects of immunosenescence on the expression of biomarkers potentially utilized in the clinical diagnosis of asthma remain unclear. It has also been shown that existing asthma treatments are less effective in the elderly. Thus, it is necessary that clinicians approach the diagnosis and treatment of asthmatic senior patients using innovative methods. Asthma in the elderly demands more intentional diagnostic and therapeutic research since it is potentially one of the few causes of mortality and morbidity in the elderly that is largely reversible.

Comparison of serum biomarkers between patients with asthma and with chronic obstructive pulmonary disease

OBJECTIVE

Asthma and chronic obstructive pulmonary disease (COPD) have distinct pathophysiological mechanisms but sometimes share similar clinical manifestations. Distinguishing between these diseases is important. This study compared the profiles of serum biomarkers between patients with asthma and those with COPD.

METHODS

Serum levels of the chitinase like protein YKL-40, periostin, interleukin (IL)-18, and chemokine (C--C motif) ligand 18 (CCL18) were measured in asthma patients (n = 20), COPD patients (n = 16), and normal controls (n = 20).

RESULTS

Serum levels of YKL-40 were higher in COPD patients [median (range), 55 (17-565) versus 208 (74-922) ng/mL, p < 0.0001], but no differences were observed between asthma and COPD patients after adjusting for age and forced expiratory volume in 1 s (FEV1). No differences in serum levels of periostin, IL-18, or CCL18 were observed between the patient groups. Total IgE and airway hypersensitivity were negatively correlated (r = -0.485, p = 0.007). CCL18 levels were related to patients' age in asthmatic patients (r = -0.562, p = 0.010). Serum levels of CCL18 and IL-18 were positively correlated in patients with COPD (r = 0.696, p = 0.003).

CONCLUSIONS

No differences in the serum profiles of periostin, IL-18, or CCL18 were observed between patients with asthma and those with COPD. Serum levels of YKL-40 were not different between asthma and COPD patients after adjusting for age and FEV1. There were negative correlation between CCL18 and age in patients with asthma and positive correlation between IL-18 and CCL18 in patients with COPD.

Female asthma has a negative effect on fertility: what is the connection?

Reproductive changes such as impaired fertility and adverse pregnancy outcomes have been related to female asthma. We recently found that time to pregnancy is prolonged in asthmatic females especially in women with moderate to severe asthma and in those above 30 years of age. Despite their reproductive difficulties the asthmatics ultimately conceived just as many biological children as healthy throughout their reproductive lives. This knowledge therefore raises questions about how asthma affects fertility pathophysiologically. The purpose of this review is to describe the existing knowledge in this field and suggest hypotheses of causal relationships, which may form the basis for future studies in this field. The aim is, in particular, in the literature to examine whether there is any evidence to suggest that the systemic inflammation that characterizes asthma, can affect fertility. The issue is potentially clinically important for asthmatic, infertile individuals and society because treatment of the general systemic inflammation associated with the asthmatic disease combined with hormone stimulation might be the optimal target for an effective infertility therapy, possibly decreasing the need for in vitro fertilization.