Biomarkers for Recurrent Wheezing and Asthma in Preschool Children

European Respiratory Society statement on preschool wheezing disorders: updated definitions, knowledge gaps and proposed future research directions

Since the publication of the European Respiratory Society (ERS) task force reports on the management of preschool wheezing in 2008 and 2014, a large body of evidence has accumulated suggesting that the clinical phenotypes that were proposed (episodic (viral) wheezing and multiple-trigger wheezing) do not relate to underlying airway pathology and may not help determine response to treatment. Specifically, using clinical phenotypes alone may no longer be appropriate, and new approaches that can be used to inform clinical care are needed for future research. This ERS task force reviewed the literature published after 2008 related to preschool wheezing and has suggested that the criteria used to define wheezing disorders in preschool children should include age of diagnosis (0 to <6 years), confirmation of wheezing on at least one occasion, and more than one episode of wheezing ever. Furthermore, diagnosis and management may be improved by identifying treatable traits, including inflammatory biomarkers (blood eosinophils, aeroallergen sensitisation) associated with type-2 immunity and differential response to inhaled corticosteroids, lung function parameters and airway infection. However, more comprehensive use of biomarkers/treatable traits in predicting the response to treatment requires prospective validation. There is evidence that specific genetic traits may help guide management, but these must be adequately tested. In addition, the task force identified an absence of caregiver-reported outcomes, caregiver/self-management options and features that should prompt specialist referral for this age group. Priorities for future research include a focus on identifying 1) mechanisms driving preschool wheezing; 2) biomarkers of treatable traits and efficacy of interventions in those without allergic sensitisation/eosinophilia; 3) the need to include both objective outcomes and caregiver-reported outcomes in clinical trials; 4) the need for a suitable action plan for children with preschool wheezing; and 5) a definition of severe/difficult-to-treat preschool wheezing.

Montelukast treatment response according to eosinophil-derived neurotoxin level in children with allergic rhinitis

BACKGROUND

Eosinophil-derived neurotoxin (EDN) is an important biomarker of eosinophilic inflammation.

METHODS

This study evaluated Montelukast treatment response according to EDN concentration in children with perennial allergic rhinitis (PAR). Fifty-two children with PAR were recruited and took a combination of Montelukast (5mg) and Levocetirizine (5mg) "Mont/Levo Group" or only Montelukast (5mg) "Mont Group" for 4 weeks. All caregivers were instructed to record rhinitis symptoms for 4 weeks. EDN was measured before and after treatment.

RESULTS

Daytime nasal symptom scores (DNSS) significantly decreased in both the Mont/Levo (p = 0.0001; n = 20) and Mont Group (p < 0.0001; n = 20), but there were no significant differences between the two groups. EDN concentration also significantly decreased after treatment in both groups (p < 0.0001 and p < 0.001, respectively). For secondary analysis, children with a high initial EDN concentration (EDN ≥ 53 ng/mL) were placed in the "High EDN Group", while those with a lower initial EDN concentration (EDN < 53 ng/mL) were put in the "Low EDN Group". Both groups experienced significant reductions in DNSS after either treatment regimen (p < 0.0001 and p = 0.0027, respectively) but the High EDN Group had greater reductions. EDN concentrations in the High EDN Group decreased significantly from either treatment (p < 0.0001).

CONCLUSION

We found that children with AR and a high serum EDN concentration may respond well to Montelukast treatment. A therapeutic strategy using EDN concentrations in patients with AR to evaluate therapeutic response may help improve quality of care.

Rhinovirus-induced wheeze was associated with asthma development in predisposed children

AIM

This study explored whether early-life factors, such as rhinovirus-induced wheeze and allergic sensitisation, were related to asthma at 11 years of age.

METHODS

We focused on 107 children aged 6-48 months, who attended the paediatric emergency department at Astrid Lindgren's Children's Hospital in Stockholm, Sweden, with acute wheeze in 2008-2012. They also attended follow-up visits at 11 years of age and were compared with 46 age-matched healthy controls. Odds ratios (OR) with 95% confidence intervals (CI) were calculated with logistic regression.

RESULTS

We found that 62.6% of the acute wheeze cases had asthma at 11 years of age. Rhinoviruses at inclusion were the only common airway viruses associated with an increased asthma risk (OR 2.4, 95% CI 1.02-5.6). Other increased risks were parental heredity for asthma and/or allergies (adjusted OR 3.4, 95% CI 1.1-9.9) and allergic sensitisation at 2 years of age (adjusted OR 3.0, 95% CI 1.02-8.7). The highest prevalence of asthma was when children had both rhinovirus-induced wheeze at inclusion and allergic sensitisation at 7 years of age.

CONCLUSION

Our findings highlight the importance of hereditary factors and allergic sensitisation on the development of asthma and suggest that rhinoviruses are associated with asthma development in predisposed children.

Risk factors associated with wheezing in severe pediatric community-acquired pneumonia: a retrospective study

BACKGROUND

Wheezing is a common clinical manifestation in children with pneumonia. However, the risk factors associated with the development of wheezing pneumonia and its clinical features are not fully characterized, especially in children with severe pneumonia.

METHODS

We retrospectively recruited 1434 pediatric patients diagnosed with severe pneumonia between April 2012 and September 2019 in Fujian Maternity and Child Health Hospital. The medical records regarding demographic information, clinical manifestations, radiographic/laboratory findings, and complications were collected. Based on the presence or absence of wheezing symptoms and signs, subjects were divided into wheezing cohort (N.=684) and non-wheezing cohort (N.=750), and their clinical data were compared. Multivariate cox regression analysis was performed to identify independent risk factors of wheezing.

RESULTS

Demographic features including gender, weigh, onset season, birth weight, full-term birth or not, history of pneumonia were significantly associated with the occurrence of wheezing in severe CAP (P<0.05). Specifically, male gender, onset seasons in autumn/winter, and absence of a history of pneumonia were identified as independent risk factors of wheezing in multivariate analysis (P<0.05). As for clinical features, wheezing cohort differed from the non-wheezing one in terms of clinical manifestation (higher incidence of cough and breathless, but lower incidence of fever), laboratory finding (higher levels of red blood cells, hemoglobin, and albumin and lower levels of total or indirect bilirubin and creatine), pathogen detection (higher incidence of respiratory syncytial viral infection), and clinical complications (lesser risk of sepsis and hydrothorax) (P<0.05).

CONCLUSIONS

Severe CAP with wheezing is a special clinical entity of severe pneumonia in children, which has specific risk factors and differ from non-wheezing pneumonia in terms of clinical features and etiologic pathogens.

[The auxiliary diagnostic value of ECP and MPO expression in nasal secretions in different types of rhinitis]

Objective:To evaluate the expression of eosinophil cationic protein and myeloperoxidase in nasal secretions in different types of rhinitis, and to explore their values in the differential diagnosis of different types of rhinitis. Methods:Six hundred and eighty-four subjects were selected, including 62 subjects in the acute rhinitis group, 378 subjects in the allergic rhinitis group, 94 subjects in the vasomotor rhinitis group, 70 subjects in the eosinophilic non-allergic rhinitis group, and 80 subjects in the control group. Nasal secretion samples were collected from the five groups, and the percentages of inflammatory cells were counted by Rachel's staining, and the expression of ECP/MPO was detected by colloidal gold assay. The correlation between the clinical diagnosis, the inflammatory cells in the nasal secretions and the expression of ECP/MPO was analyzed. Results:Nasal cytological smears showed that compared with the control group, the percentage of eosinophils in the AR and NARES groups were significantly higher （P<0.05）, while the percentage of neutrophils was not different （P>0.05）; the percentage of neutrophils was significantly higher in the acute rhinitis group compared with the control group （P<0.05）, while the percentage of eosinophils was not statistically different （P>0.05）; in vasomotor rhinitis group, the eosinophils and neutrophils were not statistically different compared with the control group（P> 0.05）. The colloidal gold results showed that there were differences in the expression of ECP/MPO in different types of rhinitis, among which 49 cases （79.0%） in the acute rhinitis group expressed ECP+/MPO+; 267 cases （70.6%） in the AR group and 56 cases （75.7%） in the NARES group expressed ECP+/MPO-; 80 cases （85.1%） in the vasomotor rhinitis group and 69 cases （86.3%） in the control group expressed ECP-/MPO-. Conclusion:The differences in ECP and MPO expression between different types of rhinitis have certain reference value for the differential diagnosis of different types of rhinitis and the selection of treatment programs.

Eosinophil-derived neurotoxin levels in early childhood and association with preschool asthma - A prospective observational study

INTRODUCTION

Eosinophil-derived neurotoxin (EDN) is related to childhood asthma, while normal values are lacking. We aimed to document serum EDN levels at 1 and 3 years in general and in non-atopic children, and explore if EDN levels differed by sex or were associated with preschool asthma at 3 years.

METHODS

From the PreventADALL birth cohort, we included 1233 children with EDN analysed using ImmunoCAP at 1 and/or 3 years. Non-atopic children had no history of wheeze, asthma, allergic sensitization or atopic dermatitis. Preschool asthma was defined as having ≥3 episodes of bronchial obstruction between 2 and 3 years, plus doctor diagnosed asthma and/or asthma medication use by 3 years. The upper limit of normal (ULN) of EDN was defined as the 95th percentile. With Youden Index we calculated EDN cut-off levels for risk of preschool asthma.

RESULTS

The overall median (ULN) EDN levels were 27.4 (121) μg/L at 1 year (n = 787), and 20.1 (87.8) μg/L at 3 years (n = 857). Non-atopic children had EDN levels of 24.0 (107) μg/L at 1 year (n = 147), and 17.3 (84.6) μg/L at 3 years (n = 173). EDN levels were higher in boys compared to girls; 32.0 (133) versus 24.5 (97.0) μg/L at 1 year, and 20.9 (96.3) versus 19.0 (72.4) μg/L at 3 years. Preschool asthma was observed in 109/892 (12.2%) children. Higher EDN levels at 1 (>26.7 μg/L) and 3 (≥20.5 μg/L) years were associated with preschool asthma; adjusted OR (95% CI) 2.20 (1.09, 4.41) and 4.68 (2.29, 9.55), respectively.

CONCLUSION AND CLINICAL RELEVANCE

We report EDN values in early childhood, demonstrating higher levels at 1 compared to 3 years and in boys compared to girls at both ages. Higher EDN levels at both ages were associated with preschool asthma. However, EDN cut-off levels for preschool asthma were overall lower than the ULN of non-atopic children, limiting translation into clinical practice.

Demystifying controversies in preschool wheeze

INTRODUCTION

Wheezing disorders in preschool children are common. Current treatment approaches assume all preschool wheezers are the same and will respond to a short course of oral corticosteroids (OCS) during acute attacks and subsequent maintenance inhaled corticosteroids (ICS) to prevent future attacks. But we have increasing evidence showing preschool wheezing disorders are markedly heterogeneous and the response to corticosteroids either during acute attacks or as maintenance therapy can be variable between patients and is determined by disease severity and underlying pathological phenotype.

AREAS COVERED

The aim of this review is to discuss recent evidence which will help to explain a few critical pathophysiological concepts that are often misunderstood, thus helping to demystify the controversies that often surround preschool wheezing disorders and can contribute to ineffective management.

EXPERT OPINION

Preschool wheezing disorders are distinct from school-age allergic asthma. There is little evidence to support the use of oral corticosteroids for acute attacks. A staged approach to confirm the diagnosis, and objective tests to determine the pathological phenotype of preschool wheeze is essential prior to initiating maintenance therapy to control symptoms and prevent attacks in children with recurrent preschool wheeze.

Expression patterns of serum miR-27a-3p and activating transcription factor 3 in children with bronchial asthma and their correlations with airway inflammation

INTRODUCTION

Bronchial asthma (BA) is a heterogeneous disease characterized by chronic airway inflammation. This study investigated the serum miR-27a-3p/activating transcription factor 3 (ATF3) expression in children with BA and their correlations with airway inflammation.

METHODS

Children with BA (N = 120) and healthy children (N = 108) were enrolled. Serum levels of interleukin (IL)-17, IL-6, tumor necrosis factor (TNF)-α, immunoglobulin E (IgE), miR-27a-3p, ATF3, and the number of eosinophils (EOS) were measured using enzyme-linked immunosorbent assay (ELISA), reverse transcription quantitative polymerase chain reaction (RT-qPCR), and an automatic hematology analyzer. The correlations between miR-27a-3p and ATF3 and between miR-27a-3p/ATF3 and inflammation-related factors were analyzed by the Pearson method. The diagnostic values of miR-27a-3p and ATF3 in BA were evaluated using receiver operating characteristic (ROC) curves. The influencing factors of BA were assessed using multivariate logistic regression. Finally, the targeting relation between miR-27a-3p and ATF3 was predicted and analyzed by TargetScan and Starbase databases, and dual-luciferase assay.

RESULTS

There were significant differences in forced expiratory volume in 1 s (FEV1)% predicted and FEV1/forced vital capacity (FVC)%, serum levels of IgE, IL-17, IL-6, and TNF-α, and EOS numbers between healthy children and BA children. Serum miR-27a-3p was negatively correlated with ATF3 and positively correlated with inflammation-related factors in BA children. Serum ATF3 mRNA levels were negatively correlated with inflammatory factors in BA children. miR-27a-3p and ATF3 had good diagnostic values in BA children. FEV% predicted, IL-6, TNF-α, miR-27a-3p, and ATF3 were independent risk factors for BA. miR-27a-3p targeted ATF3.

CONCLUSION

Serum miR-27a-3p was highly expressed, whereas ATF3 was poorly expressed in BA children, and they were significantly correlated with airway inflammation, had good diagnostic values in BA children, and were independent risk factors for asthma.

Risk factors for recurrent wheezing after bronchiolitis

BACKGROUND

This study aimed to determine whether there was an association between certain factors in patients with bronchiolitis and recurrent wheezing in childhood.

METHOD

In 2021 we tracked children hospitalized for bronchiolitis at Chengdu Women's and Children's Central Hospital in 2017. The patients were classified into recurrent wheezing group (RWG) and non-recurrent wheezing group (NRWG). Possible risk factors including maternal age, school-age siblings, allergic history, atopic dermatitis, allergic rhinitis, atopic family history, severity of the condition, duration of hospitalization, nasopharyngeal secretions culture, blood eosinophil counts, FeNO and skin prick test were compared between the two groups. Continuous variables were analyzed by independent sample t-test for normal distribution and Mann-Whitney U-test for non-normal distribution. Categorical variables were tested using chi-square tests. Multifactor analysis was conducted by stepwise logistics regression analysis.

RESULTS

In total 167 participants were included, of which 26 and 141 were in RWG and NRWG respectively. In RWG children represented higher maternal age (P = 0.02) and greater probability of allergic history, atopic dermatitis, allergic rhinitis, atopic family history (odds ratio [OR] = 4.0,3.7, 7.8, 10.9 respectively, P < 0.01). However, school-age siblings, severity of the condition, duration of hospitalization, blood eosinophil counts, fractional exhaled nitric oxide and skin prick test results seemed unrelated to recurrent wheezing. In the subgroup analysis of nasopharyngeal secretion culture, there were more Moraxella catarrhalis-positive in RWG(P = 0.043). Atopic dermatitis, allergic rhinitis and atopic family history were identified as independent risk factors for recurrent wheezing.

CONCLUSION

Some children with bronchiolitis will develop recurrent wheezing, and the risk factors are allergic history, Moraxella catarrhalis infection or colonization, atopic dermatitis, allergic rhinitis and atopic family history; the latter three are independent risk factors.

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.

The Role of Eosinophil-Derived Neurotoxin and Vascular Endothelial Growth Factor in the Pathogenesis of Eosinophilic Asthma

Asthma is a chronic complex pulmonary disease characterized by airway inflammation, remodeling, and hyperresponsiveness. Vascular endothelial growth factor (VEGF) and eosinophil-derived neurotoxin (EDN) are two significant mediators involved in the pathophysiology of asthma. In asthma, VEGF and EDN levels are elevated and correlate with disease severity and airway hyperresponsiveness. Diversity in VEGF polymorphisms results in the variability of responses to glucocorticosteroids and leukotriene antagonist treatment. Targeting VEGF and eosinophils is a promising therapeutic approach for asthma. We identified lichochalcone A, bevacizumab, azithromycin (AZT), vitamin D, diosmetin, epigallocatechin gallate, IGFBP-3, Neovastat (AE-941), endostatin, PEDF, and melatonin as putative add-on drugs in asthma with anti-VEGF properties. Further studies and clinical trials are needed to evaluate the efficacy of those drugs. AZT reduces the exacerbation rate and may be considered in adults with persistent symptomatic asthma. However, the long-term effects of AZT on community microbial resistance require further investigation. Vitamin D supplementation may enhance corticosteroid responsiveness. Herein, anti-eosinophil drugs are reviewed. Among them are, e.g., anti-IL-5 (mepolizumab, reslizumab, and benralizumab), anti-IL-13 (lebrikizumab and tralokinumab), anti-IL-4 and anti-IL-13 (dupilumab), and anti-IgE (omalizumab) drugs. EDN over peripheral blood eosinophil count is recommended to monitor the asthma control status and to assess the efficacy of anti-IL-5 therapy in asthma.

Clinical efficacy of antileukotriene therapy in children with acute bronchitis

Recurrent episodes of bronchial obstruction in preschool children are one of the important risk factors for the development of bronchial asthma.Purpose. The study aimed at investigating the clinical and immunological characteristics of children with acute bronchitis and to determine the clinical effectiveness of course anti-inflammatory therapy.Material and methods. The study was a single-center prospective cohort, including 1–5-year-old patients with acute bronchitis (main group, n = 109): a group with acute simple bronchitis (n = 34) and acute obstructive bronchitis (n = 75). Reference group: children of health group 2 (n = 29). Clinical and anamnestic and laboratory methods were used. Patients with a positive API (Asthma Predictive Index) were administered montelukast at a dose of 4 mg orally once a day for 3 months (control points at 1 and 3 months), reference patients received symptomatic therapy for respiratory infection. The end point of the study is the absence of bronchial obstruction. The effectiveness of the use of Montelukast was evaluated by calculating the clinical index, efficiency coefficient. Results. A statistically significant predominance of intoxication symptoms was found in patients with acute simple bronchitis (p = 0.02), signs of respiratory failure (p < 0.001), and peripheral eosinophilia — in children with acute obstructive bronchitis (p = 0.02). In etiology, rhinovirus significantly prevailed in patients with bronchial obstruction, and RS virus prevailed in patients with acute simple bronchitis (p = 0.02). The cytokine profile of patients with acute obstructive bronchitis is characterized by a decrease in the levels of macrophage inflammatory proteins (p = 0.01) and IL-8 (p = 0.048). A prolonged course of montelukast in children with a positive API significantly reduces the severity of subsequent acute respiratory infections, reduces the frequency of bronchial obstruction and the risk of bronchial asthma (p < 0.001).Conclusion. Evaluation of the results of montelukast therapy demonstrated clinical efficacy in patients with a positive API index.

Machine learning model for classification of predominantly allergic and non-allergic asthma among preschool children with asthma hospitalization

OBJECTIVE

Asthma is the most frequent chronic airway illness in preschool children and is difficult to diagnose due to the disease's heterogeneity. This study aimed to investigate different machine learning models and suggested the most effective one to classify two forms of asthma in preschool children (predominantly allergic asthma and non-allergic asthma) using a minimum number of features.

METHODS

After pre-processing, 127 patients (70 with non-allergic asthma and 57 with predominantly allergic asthma) were chosen for final analysis from the Frankfurt dataset, which had asthma-related information on 205 patients. The Random Forest algorithm and Chi-square were used to select the key features from a total of 63 features. Six machine learning models: random forest, extreme gradient boosting, support vector machines, adaptive boosting, extra tree classifier, and logistic regression were then trained and tested using 10-fold stratified cross-validation.

RESULTS

Among all features, age, weight, C-reactive protein, eosinophilic granulocytes, oxygen saturation, pre-medication inhaled corticosteroid + long-acting beta2-agonist (PM-ICS + LABA), PM-other (other pre-medication), H-Pulmicort/celestamine (Pulmicort/celestamine during hospitalization), and H-azithromycin (azithromycin during hospitalization) were found to be highly important. The support vector machine approach with a linear kernel was able to diffrentiate between predominantly allergic asthma and non-allergic asthma with higher accuracy (77.8%), precision (0.81), with a true positive rate of 0.73 and a true negative rate of 0.81, a F1 score of 0.81, and a ROC-AUC score of 0.79. Logistic regression was found to be the second-best classifier with an overall accuracy of 76.2%.

CONCLUSION

Predominantly allergic and non-allergic asthma can be classified using machine learning approaches based on nine features.

Supplemental data for this article is available online at at www.tandfonline.com/ijas .

[Markers of severity and predictors of response to treatment in severe asthma]

Asthma is a multifactorial disease with complex pathophysiology. Knowledge of its immunopathology and inflammatory mechanisms is progressing and has led to the development over recent years of increasingly targeted therapeutic strategies. The objective of this review is to pinpoint the different predictive markers of asthma severity and therapeutic response. Obesity, nasal polyposis, gastroesophageal reflux disease and intolerance to aspirin have all been considered as clinical markers associated with asthma severity, as have functional markers such as bronchial obstruction, low FEV1, small daily variations in FEV1, and high FeNO. While sinonasal polyposis and allergic comorbidities are associated with better response to omalizumab, nasal polyposis or long-term systemic steroid use are associated with better response to antibodies targeting the IL5 pathway. Elevated total IgE concentrations and eosinophil counts are classic biological markers regularly found in severe asthma. Blood eosinophils are predictive biomarkers of response to anti-IgE, anti-IL5, anti-IL5R and anti-IL4R biotherapies. Dupilumab is particularly effective in a subgroup of patients with marked type 2 inflammation (long-term systemic corticosteroid therapy, eosinophilia≥150/μl or FENO>20 ppb). Chest imaging may help to identify severe patients by seeking out bronchial wall thickening and bronchial dilation. Study of the patient's environment is crucial insofar as exposure to tobacco, dust mites and molds, as well as outdoor and indoor air pollutants (cleaning products), can trigger asthma exacerbation. Wider and more systematic use of markers of severity or response to treatment could foster increasingly targeted and tailored approaches to severe asthma.

[Diagnostic value of a novel test paper detection of ECP in nasal secretion for allergic rhinitis]

Objective:To explore the diagnostic value of a novel test paper, which detect eosinophil cationic protein（ECP） of nasal secretion in allergic rhinitis（AR）. Methods:Nasal secretion and serum samples from 107 patients with allergic rhinitis（AR group） and 40 healthy volunteers（control group） were selected. The nasal symptoms were also evaluated in AR group. The degree of ECP coloration was evaluated by nasal secretion eosinophil cationic protein-myeloperoxid（ECP-MPO） test paper, and the concentration of ECP in nasal secretion and the concentration of cytokines in serum were detected at the same time. The difference and correlation among these indexes were analyzed. The best cutoff value and test efficiency of ECP chromogenic grade and concentration of nasal secretion were calculated by receiver operating characteristic curve（ROC）. Results:The concentration of ECP in nasal secretion of AR patients was significantly higher than that of healthy controls（P<0.05）. The color grade of nasal secretion detected by the test paper was positively correlated with the concentration of ECP in nasal secretion（P<0.05）, and there was significant difference among different grades（P<0.05）. There was a satisfying symmetry between the ECP color grade of nasal secretion and the serum specific IgE（sIgE） level as well as a high diagnostic consistency between them（P<0.05）. The area under the curve（AUC） of ECP concentration ROC in nasal secretion was 0.807 2, corresponding to 64% sensitivity and 85% specificity when the cutoff value was set at 0.980 5; when the cutoff value was set at 1, the AUC of nasal secretion ECP color grading was 0.941 9, corresponding to 92% sensitivity and 94% specificity. No clear correlation between the concentration of ECP in nasal secretion and serum cytokines was found（P>0.05）. Conclusion:The results of this novel test paper is in good agreement with those of serological allergens. It could serve as a preliminary test to evaluate the severity of allergy with satisfactory sensitivity and specificity, and is especially suitable in clinical practice for primary hospital.

Emerging Roles of Non-Coding RNAs in Childhood Asthma

Asthma is a chronic airway inflammatory disease in children characterized by airway inflammation, airway hyperresponsiveness and airway remodeling. Childhood asthma is usually associated with allergy and atopy, unlike adult asthma, which is commonly associated with obesity, smoking, etc. The pathogenesis and diagnosis of childhood asthma also remains more challenging than adult asthma, such as many diseases showing similar symptoms may coexist and be confused with asthma. In terms of the treatment, although most childhood asthma can potentially be self-managed and controlled with drugs, approximately 5-10% of children suffer from severe uncontrolled asthma, which carries significant health and socioeconomic burdens. Therefore, it is necessary to explore the pathogenesis of childhood asthma from a new perspective. Studies have revealed that non-coding RNAs (ncRNAs) are involved in the regulation of respiratory diseases. In addition, altered expression of ncRNAs in blood, and in condensate of sputum or exhalation affects the progression of asthma via regulating immune response. In this review, we outline the regulation and pathogenesis of asthma and summarize the role of ncRNAs in childhood asthma. We also hold promise that ncRNAs may be used for the development of biomarkers and support a new therapeutic strategy for childhood asthma.

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.

Identification and seasonality of rhinovirus and respiratory syncytial virus in asthmatic children in tropical climate

INTRODUCTION

Asthma is a disease that has been associated with the presence of different genetic and socio-environmental factors.

OBJECTIVE

To identify and evaluate the seasonality of respiratory syncytial virus (RSV) and human rhinovirus (RV) in asthmatic children and adolescents in tropical climate, as well as to assess the socioeconomic and environmental factors involved.

METHODS

The study was conducted in a referral hospital, where a total of 151 children were recruited with a respiratory infection. The International Study of Asthma and Allergies in Childhood (ISAAC) protocol and a questionnaire were applied, and a skin prick test was performed. The nasal swab was collected to detect RV and RSV through molecular assay. National Meteorological Institute (INMET) database was the source of climatic information.

RESULTS

The socio-environmental characterization of asthmatic children showed the family history of allergy, disturbed sleep at night, dry cough, allergic rhinitis, individuals sensitized to at least one mite. We identified RV in 75% of children with asthma and 66.7% of RSV in children with asthma. There was an association between the presence of RV and the dry season whereas the presence of the RSV was associated with the rainy season. Contributing to these results, a negative correlation was observed between the RSV and the wind speed and the maximum temperature (T. Max) and a positive correlation with precipitation.

CONCLUSIONS

The results suggest a high prevalence of RV and RSV in asthmatic children and the seasonality of these viruses were present in different climatic periods. This has significant implications for understanding short- and long-term clinical complications in asthmatic patients.

Can serum periostin, YKL-40, and osteopontin levels in pre-school children with recurrent wheezing predict later development of asthma?

BACKGROUND

Currently, there are no reliable clinical tools available for predicting asthma in pre-school-aged children with recurrent wheezing. The aim of this study was to evaluate the usefulness of serum periostin, YKL-40, and osteopontin biomarkers in wheezy pre-school-aged children for predicting the development of asthma in school ages.

METHODS

The study was prospectively conducted between 2011 and 2017. The clinical features of the pre-school-aged children with recurrent wheezing and the levels of serum periostin, YKL-40, and osteopontin were measured. The same participants were reevaluated in school-age period, and participants with asthma were identified. Relative risk (RR) for the development of asthma was analyzed.

RESULTS

Of the 197 pre-school-aged children with recurrent wheezing who were reevaluated in school-age years, 32% of them had asthma. Serum periostin, YKL-40, and osteopontin levels at admission could not predict participants who would have asthma symptoms in school-age years. The RR for continuing of asthma symptoms was higher in participants who had their first wheezing episode before 1 year of age, preterm birth, cesarean section delivery, prenatal smoking exposure, multi-trigger wheezing, parental asthma, modified asthma predictive index positivity, prophylactic vitamin D intake ≤ 12 months, breastfeeding time ≤ 12 month, and aeroallergen sensitivity [RR (95% CI) and P value: 2.813 (1.299-6.091), 0.002; 1.972 (1.274-3.052), 0.009; 1.929 (1.195-3.114), 0.004; 2.232 (1.463-3.406), <0.001; 3.152 (1.949-5.097), <0.001; 1.730 (1.144-2.615), 0.016; 2.427 (1.559-3.777), <0.001; 2.955 (1.558-5.604), <0.001; 1.767 (1.084-2.881), 0.016; 0.765 (0.556-1.053), 0.016; respectively].

CONCLUSION

Results have shown that clinical features were more valuable than biomarkers in predicting having asthma in school-age years in participants who had recurrent wheezing in pre-school-age period.

Reduced Exhaled Breath Condensate pH and Severity of Allergic Sensitization Predict School Age Asthma

BACKGROUND

We previously reported that deaerated breath condensate pH (dEBC pH) can identify preschool children with recurrent wheezing at high asthma risk.

OBJECTIVE

To assess the ability of preschool dEBC pH to predict asthma risk at school age.

METHODS

Children of the baseline cohort were recontacted for follow-up. Asthma diagnosis at school age was evaluated according to Global Initiative for Asthma recommendations in 135 children who at baseline had been classified into the following groups: (asymptomatic) atopic wheezers (n = 30), (asymptomatic) nonatopic wheezers (n = 57), allergic rhinitis only (n = 14), and healthy controls (n = 34).

RESULTS

All (100%) former atopic wheezers, 12 (21%) of nonatopic wheezers, 2 (14%) of allergic rhinitis group, and 1 (3%) of healthy controls had developed asthma at follow-up. Among all children with baseline wheezing, baseline dEBC pH predicted asthma at follow-up with an area under the receiver operating characteristic curve (AUC) of 0.72 (sensitivity, 0.67; specificity, 0.76; at pH 7.83). Combining pH and Capacity class (CAP) led to substantial gain in sensitivity (0.96) and negative predictive value (NPV, 0.94). Additional clinical information (Asthma Predictive Index, family atopy, family asthma, and inhaled corticosteroids) further increased the potential to predict asthma (AUC, 0.94) and raised sensitivity (0.98) and NPV (0.97) to nearly perfect values.

CONCLUSION

Our findings suggest (1) that dEBC pH combined with CAP class may serve as highly sensitive, noninvasive marker for the early detection of young asymptomatic preschool children with increased asthma risk, and (2) the need for additional biomarkers with high specificity to optimize early risk stratification in this clinically challenging scenario.

Montelukast use over the past 20 years: monitoring of its effects and safety issues

Montelukast, a leukotriene receptor antagonist, was launched 20 years ago in Korea. It is recommended as an alternative treatment for asthma in children with mild persistent symptoms or as an add-on treatment to existing low-dose inhaled corticosteroids (ICSs) in children who require additional treatment. However, in the real-world setting, many doctors and patients prefer montelukast over ICSs despite their lower efficacy. Although montelukast is considered to be a safe drug, there are concerns regarding adverse drug reactions, including the rare occurrence of Churg-Strauss syndrome and, despite insufficient data, the possibility of neuropsychiatric events such as anxiety, depression, sleep disturbance, and suicidality. This review identified that montelukast has significantly contributed to asthma control over the past 20 years in Korea and has been critical for reducing asthma severity, especially early wheezing and disease control. Our findings suggest that the effects of montelukast treatment can be monitored by measuring serum eosinophilderived neurotoxin levels.

Serum potential biomarkers according to sputum inflammatory cell profiles in adult asthmatics

BACKGROUND/AIMS

Asthma is not a single disease but, rather, a heterogeneous inf lammatory disorder with various pathogenic mechanisms. We analyzed the associations between the cellular profile of sputum and the serum levels of inflammatory mediators/cytokines in a cohort of adult asthmatics.

METHODS

We recruited 421 adult asthmatic patients. All subjects were classified into four groups according to their sputum cellular profiles: G1, eosinophilic; G2, mixed granulocytic; G3, neutrophilic; and G4, paucigranulocytic. Serum levels of cytokines and mediators including periostin, eosinophil-derived neurotoxin (EDN), S100A9, and folliculin were quantified.

RESULTS

Among 421 patients, G1 accounted for 149 (35.4%), G2 for 71 (16.9%), G3 for 155 (36.8%), and G4 for 46 (10.9%). Serum periostin and EDN levels were significantly higher in G1 (p = 0.004, and p = 0.031) than in the others. Serum S100A9 levels were elevated in G2 and G3 (p = 0.008). Serum folliculin levels differed significantly among the four groups, with the highest level in G4 (p = 0.042). To identify G1 from G1 plus G2 groups, the optimal serum cut-off levels were 1.71 ng/mL for periostin, and 1.61 ng/mL for EDN. When these two parameters were combined, the sensitivity was 76.0% and the specificity was 64.3% (area under the curve, 0.701; p = 0.004).

CONCLUSION

The serum periostin and EDN levels may be used as predictors to discriminate the eosinophilic asthma group from patients having eosinophilic or mixed granulocytic asthma, and the serum folliculin level is significantly elevated in patients with paucigranulocytic asthma compared to those with different inflammatory cell profile.

Serum Eosinophil-Derived Neurotoxin Better Reflect Asthma Control Status Than Blood Eosinophil Counts

BACKGROUND

Although several biomarkers have been proposed for eosinophilic asthma, biomarkers for reflecting asthma control status remain controversial. Eosinophil-derived neurotoxin (EDN), a degranulated eosinophil protein, is an emerging biomarker in asthmatic patients.

OBJECTIVE

This study analyzed serum EDN concentrations in asthmatics and compared its performance with that of blood eosinophil count as an indicator of asthma control status.

METHODS

We enrolled 75 uncontrolled asthmatics, 56 controlled asthmatics, and 43 healthy controls from Asan Medical Center. Serum EDN levels (ng/mL) were measured using an enzyme-linked immunosorbent assay kit. The predictability of EDN for asthma control status was analyzed by univariate and multivariable logistic regression analyses. A receiver operating characteristic (ROC) curve analysis was conducted to compare the performances of a serum EDN level and blood eosinophil count as indicators of uncontrolled asthma status.

RESULTS

The mean serum EDN level in the uncontrolled asthma group was higher than that in the controlled asthma and healthy groups (103.2 ± 60.2 vs 60.8 ± 49.7 vs 49.6 ± 28.3 ng/mL, P < .001). Serum EDN level was the significant parameter related to asthma control status in univariate and multivariable analysis (both P < .001). Serum EDN levels correlated with blood eosinophil counts (r = 0.510, P < .001). However, in the ROC analysis, serum EDN level showed a significantly better performance for predicting uncontrolled asthma status (area under the curve, 0.726 vs 0.628, P = .024).

CONCLUSIONS

Serum EDN levels significantly differed between patients with controlled and uncontrolled status in adult asthmatics. To our knowledge, this is the first study to identify EDN as a better indicator of asthma control status than blood eosinophil count.

Transforming growth factor-β1 and eosinophil-derived neurotoxins contribute to the development of work-related respiratory symptoms in bakery workers

Background

In baker's asthma previous studies suggest that adaptive and innate immunity are involved in the development of work-related respiratory symptoms (WRS), where we hypothesized that epithelial cells derive airway inflammation through modulating the release of inflammatory cytokines. Thus, we conducted this study to investigate the role of epithelial cell-derived cytokines in the development of WRS among bakery workers.

Methods

We recruited 385 wheat-exposed subjects with WRS (WRS+)/without WRS (WRS-) working in a single industry and 243 unexposed controls from Ajou Medical Center (Suwon, South Korea). Levels of epithelial cell-derived cytokines (interleukin [IL-8], transforming growth factor-β1 [TGF-β1], eotaxin-2) and inflammatory mediators (eosinophil-derived neurotoxins [EDN]) in sera or cell-free supernatants were measured by ELISA. Human airway epithelial cells (HAECs), A549, were stimulated by wheat flour extracts and co-cultured with peripheral blood neutrophils isolated from 4 asthmatic patients.

Results

Serum TGF-β1 levels were significantly lower in exposed subjects than in unexposed controls, in the WRS+ group than in the WRS- group (P < 0.001 for each). The WRS+ group had a significantly higher level of serum EDN than the WRS- group (P < 0.001). Serum TGF-β1 and EDN levels predicted the development of WRS in exposed subjects (area under the curve [AUC] = 0.719, 72.4% sensitivity/70% specificity; AUC = 0.759, 78.6% sensitivity/60% specificity). From wheat-stimulated HAECs, TGF-β1 release peaked at 6 hours after wheat exposure, while eotaxin-2 peaked at 12 hours. Co-culture of HAECs with neutrophils did not affect TGF-β1 release.

Conclusions

Our results suggest that TGF-β1 may contribute to develop type-2 airway inflammation and WRS. Serum TGF-β1/EDN levels may be potential serum biomarkers for predicting WRS among bakery workers.