Relationships among aeroallergen sensitization, peripheral blood eosinophils, and periostin in pediatric asthma development

Association of Sputum Eosinophilia With Easily Measured Type-2 Inflammatory Biomarkers in Untreated Mild Persistent Asthma

BACKGROUND

A multicenter clinical trial in patients with mild persistent asthma indicated that response to inhaled corticosteroids (ICS) is limited to those with sputum eosinophilia. However, testing for sputum eosinophilia is impractical in most clinical settings.

OBJECTIVE

We examined associations between sputum eosinophilia and type 2 inflammatory biomarkers in untreated mild persistent asthma.

METHODS

Induced sputum, blood eosinophil count (BEC), fractional exhaled nitric oxide (FeNO), and serum periostin were obtained twice during the 6-week run-in period in a clinical trial that enrolled patients 12 years and older with symptomatic, mild persistent asthma without controller therapy. The optimal threshold for each biomarker was based on achieving 80% or greater sensitivity. Performance of biomarkers (area under the receiver operating characteristics curve [AUC], range 0.0-1.0) in predicting sputum eosinophilia 2% or greater was determined; AUCs of 0.8 to 0.9 and more than 0.9 define excellent and outstanding discrimination, respectively.

RESULTS

Of 564 participants, 27% were sputum eosinophilic, 83% were atopic, 70% had BEC of 200/uL or higher or FeNO of 25 ppb or greater; 64% of participants without sputum eosinophilia had elevated BEC or FeNO. The AUCs for BEC, FeNO, and both together in predicting sputum eosinophilia were all below the threshold for excellent discrimination (AUC 0.75, 0.78, and 0.79, respectively). Periostin (in adults) had poor discrimination (AUC 0.59; P = .02).

CONCLUSIONS

In untreated mild persistent asthma, there is substantial discordance between sputum eosinophilia, BEC, and FeNO. Until prospective trials test the ability of alternative biomarkers to predict ICS response, BEC or FeNO phenotyping may be an option to consider ICS through a shared decision-making process with consideration of other clinical features.

Heavy metal levels are positively associated with serum periostin and miRNA-125b levels, but inversely associated with miRNA-26a levels in pediatric asthma cases. A case-control study

BACKGROUND

The study investigated heavy metals levels [urinary cadmium (U-Cd), erythrocytic cadmium (E-Cd), urinary arsenic (U-As), and whole blood lead (WB-Pb)] in children with bronchial asthma (BA) and tested their associations with serum periostin, miRNA-125b and miRNA-26a levels, and with asthma severity clinically and laboratory [blood eosinophils count (BEC) and serum total immunoglobin E (IgE)]. Also, we tested cut-off points, for the studied parameters, to distinguish BA cases from healthy children.

METHODS

This case-control study included 158 children divided into control group; n = 72 and BA group; n = 86. Heavy metals were measured by an inductively coupled plasma-optical emission spectrophotometer. Serum periostin and IgE levels were measured by their corresponding ELISA kits. miRNAs relative expressions were estimated by RT-qPCR using the 2-ΔΔCT method.

RESULTS

Heavy metals, serum periostin, and miR-125b levels were significantly high in BA group (p < 0.001). Heavy metals levels correlated positively with serum periostin, miR-125b and IgE levels, BEC, and asthma severity. The reverse was observed regarding serum miR-26a levels. Receiver operating characteristics (ROC) curve analysis showed good to excellent abilities of U-Cd, E-Cd, U-As, WB-Pb, serum periostin, miRNA-125b, and miRNA - 26a, and total IgE levels to distinguish BA cases from healthy children.

CONCLUSIONS

Heavy metal toxicity in children is associated with BA severity, increased serum periostin and miRNA-125b levels, and decreased miRNA-26a levels. Specific measures to reduce children's exposure to heavy metals should be taken. Future research should consider blocking miRNA-125b action or enhancing miRNA-26a action to manage BA cases.

A systematic review and meta-analysis on absolute eosinophil counts and the risk of asthma in preschool children with wheezing: An EAACI Task Force Report

Preschool children with wheezing disorders pose diagnostic and therapeutic challenges and consume substantial healthcare resources. Peripheral eosinophil blood count (EBC) has been proposed as a potential indicator for future asthma development. This review by the European Academy of Allergy and Clinical Immunology (EAACI) Preschool Wheeze Task Force aimed to provide systematic evidence for the association between increased EBC and the risk of future asthma, as well as to identify potential cutoff values. In February 2023, a search of PubMed, EMBASE, and Cochrane Library databases was conducted to identify studies comparing EBCs in preschool children with wheezing who continued to wheeze later in life and those who did not. Included observational studies focused on children aged <6 years with a wheezing disorder, assessment of their EBCs, and subsequent asthma status. No language or publication date restrictions were applied. Among the initial 3394 studies screened, 10 were included in the final analysis, involving 1225 patients. The data from these studies demonstrated that high EBC in preschool children with wheezing is associated with future asthma development, with odds ratios of 1.90 (95% CI: 0.45-7.98, p = .38), 2.87 (95% CI: 1.38-5.95, p < .05), and 3.38 (95% CI: 1.72-6.64, p < .05) for cutoff values in the <300, 300-449, and ≥450 cells/μL ranges, respectively. Defining a specific cutoff point for an elevated EBC lacks consistency, but children with EBC >300 cells/μL are at increased risk of asthma. However, further research is needed due to the limitations of the included studies. Future investigations are necessary to fully elucidate the discussed association.

Limited clinical role of blood eosinophil levels in early life atopic disease: A mother-child cohort study

BACKGROUND

Blood eosinophil count is a well-established biomarker of atopic diseases in older children and adults. However, its predictive role for atopic diseases in preschool children is not well established.

OBJECTIVE

To investigate the association between blood eosinophil count in children and development of atopic diseases up to age 6 years.

METHODS

We investigated blood eosinophil count at age 18 months and 6 years in relation to recurrent wheeze/asthma, atopic dermatitis, allergic rhinitis, and allergic sensitization during the first 6 years of life in the two Copenhagen Prospective Studies on Asthma in Childhood cohorts (n = 1111). Blood eosinophil count was investigated in association with remission of existing atopic disease, current atopic disease, and later development of atopic disease.

RESULTS

Blood eosinophil count at 18 months was not associated with current wheezing/asthma or atopic dermatitis, while blood eosinophil count at age 6 years was associated with increased occurrence of current wheezing/asthma (OR = 1.1; 1.04-1.16, p = .0005), atopic dermatitis (OR = 1.06; 1.01-1.1, p = .02), and allergic rhinitis (OR = 1.11; 1.05-1.18, p = .0002). Blood eosinophil count at 18 months did not predict persistence or development of recurrent wheeze/asthma or atopic dermatitis at age 6 years.

CONCLUSION

Blood eosinophil count at 18 months was not associated with current wheezing/asthma or atopic dermatitis and did not predict persistence or development of disease. This implies a limited clinical role of blood eosinophil levels in early-life atopic disease and questions the clinical value of blood eosinophil counts measured in toddlers as a predictive biomarker for subsequent atopic disease in early childhood.

Early Prediction of Asthma

The clinical manifestations of asthma in children are highly variable, are associated with different molecular and cellular mechanisms, and are characterized by common symptoms that may diversify in frequency and intensity throughout life. It is a disease that generally begins in the first five years of life, and it is essential to promptly identify patients at high risk of developing asthma by using different prediction models. The aim of this review regarding the early prediction of asthma is to summarize predictive factors for the course of asthma, including lung function, allergic comorbidity, and relevant data from the patient's medical history, among other factors. This review also highlights the epigenetic factors that are involved, such as DNA methylation and asthma risk, microRNA expression, and histone modification. The different tools that have been developed in recent years for use in asthma prediction, including machine learning approaches, are presented and compared. In this review, emphasis is placed on molecular mechanisms and biomarkers that can be used as predictors of asthma in children.

Association between Exposure to Selected Heavy Metals and Blood Eosinophil Counts in Asthmatic Adults: Results from NHANES 2011-2018

(1) Background: Heavy metals are widely used and dispersed in the environment and people's daily routines. Many studies have reported an association between heavy metal exposure and asthma. Blood eosinophils play a crucial role in the occurrence, progression, and treatment of asthma. However, there have thus far been few studies that aimed to explore the effects of heavy metal exposure on blood eosinophil counts in adults with asthma. Our study aims to discuss the association between metal exposure and blood eosinophil counts among asthmatic adults. (2) Methods: A total of 2026 asthmatic individuals were involved in our research from NHANES with metal exposure, blood eosinophils, and other covariates among the American population. A regression model, the XGBoost algorithm, and a generalized linear model (GAM) were used to explore the potential correlation. Furthermore, we conducted a stratified analysis to determine high-risk populations. (3) Results: The multivariate regression analysis indicated that concentrations of blood Pb (log per 1 mg/L; coefficient β, 25.39; p = 0.010) were positively associated with blood eosinophil counts. However, the associations between blood cadmium, mercury, selenium, manganese, and blood eosinophil counts were not statistically significant. We used stratified analysis to determine the high-risk group regarding Pb exposure. Pb was identified as the most vital variable influencing blood eosinophils through the XGBoost algorithm. We also used GAM to observe the linear relationship between the blood Pb concentrations and blood eosinophil counts. (4) Conclusions: The study demonstrated that blood Pb was positively correlated with blood eosinophil counts among asthmatic adults. We suggested that long-time Pb exposure as a risk factor might be correlated with the immune system disorder of asthmatic adults and affect the development, exacerbation, and treatment of asthma.

Blood-Based Biomarkers for Eosinophilic Esophagitis and Concomitant Atopic Diseases: A Look into the Potential of Extracellular Vesicles

Eosinophilic esophagitis (EoE) is a chronic, Th2-inflammatory disease of the esophagus that can severely affect food intake. Currently, diagnosis and assessing response to treatment of EoE is highly invasive and requires endoscopy with esophageal biopsies. Finding non-invasive and accurate biomarkers is important for improving patient well-being. Unfortunately, EoE is usually accompanied by other atopies, which make it difficult to identify specific biomarkers. Providing an update of circulating EoE biomarkers and concomitant atopies is therefore timely. This review summarizes the current knowledge in EoE blood biomarkers and two of its most common comorbidities, bronchial asthma (BA) and atopic dermatitis (AD), focusing on dysregulated proteins, metabolites, and RNAs. It also revises the current knowledge on extracellular vesicles (EVs) as non-invasive biomarkers for BA and AD, and concludes with the potential use of EVs as biomarkers in EoE.

Network analyses of upper and lower airway transcriptomes identify shared mechanisms among children with recurrent wheezing and school-age asthma

Background

Predicting which preschool children with recurrent wheezing (RW) will develop school-age asthma (SA) is difficult, highlighting the critical need to clarify the pathogenesis of RW and the mechanistic relationship between RW and SA. Despite shared environmental exposures and genetic determinants, RW and SA are usually studied in isolation. Based on network analysis of nasal and tracheal transcriptomes, we aimed to identify convergent transcriptomic mechanisms in RW and SA.

Methods

RNA-sequencing data from nasal and tracheal brushing samples were acquired from the Gene Expression Omnibus. Combined with single-cell transcriptome data, cell deconvolution was used to infer the composition of 18 cellular components within the airway. Consensus weighted gene co-expression network analysis was performed to identify consensus modules closely related to both RW and SA. Shared pathways underlying consensus modules between RW and SA were explored by enrichment analysis. Hub genes between RW and SA were identified using machine learning strategies and validated using external datasets and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Finally, the potential value of hub genes in defining RW subsets was determined using nasal and tracheal transcriptome data.

Results

Co-expression network analysis revealed similarities in the transcriptional networks of RW and SA in the upper and lower airways. Cell deconvolution analysis revealed an increase in mast cell fraction but decrease in club cell fraction in both RW and SA airways compared to controls. Consensus network analysis identified two consensus modules highly associated with both RW and SA. Enrichment analysis of the two consensus modules indicated that fatty acid metabolism-related pathways were shared key signals between RW and SA. Furthermore, machine learning strategies identified five hub genes, i.e., CST1, CST2, CST4, POSTN, and NRTK2, with the up-regulated hub genes in RW and SA validated using three independent external datasets and qRT-PCR. The gene signatures of the five hub genes could potentially be used to determine type 2 (T2)-high and T2-low subsets in preschoolers with RW.

Conclusions

These findings improve our understanding of the molecular pathogenesis of RW and provide a rationale for future exploration of the mechanistic relationship between RW and SA.

Nasal TSLP and periostin in infants with severe bronchiolitis and risk of asthma at 4 years of age

BACKGROUND

Severe bronchiolitis is often associated with subsequent respiratory morbidity, mainly recurrent wheezing and asthma. However, the underlying immune mechanisms remain unclear. The main goal of this study was to investigate the association of nasal detection of periostin and thymic stromal lymphopoietin (TSLP) during severe bronchiolitis with the development of asthma at 4 years of age.

METHODS

Observational, longitudinal, post-bronchiolitis, hospital-based, follow-up study. Children hospitalized for bronchiolitis between October/2013 and July/2017, currently aged 4 years, included in a previous study to investigate the nasal airway secretion of TSLP and periostin during bronchiolitis, were included. Parents were contacted by telephone, and were invited to a clinical interview based on a structured questionnaire to obtain information on the respiratory evolution. The ISAAC questionnaire for asthma symptoms for 6-7-year-old children, was also employed.

RESULTS

A total of 248 children were included (median age 4.4 years). The mean age at admission for bronchiolitis was 3.1 (IQR: 1.5-6.5) months. Overall, 21% had ever been diagnosed with asthma and 37% had wheezed in the last 12 months. Measurable nasal TSLP was detected at admission in 27(11%) cases and periostin in 157(63%). The detection of nasal TSLP was associated with the subsequent prescription of maintenance asthma treatment (p = 0.04), montelukast (p = 0.01), and the combination montelukast/inhaled glucocorticosteroids (p = 0.03). Admissions for asthma tended to be more frequent in children with TSLP detection (p = 0.07). In the multivariate analysis, adjusting for potential confounders, the detection of TSLP remained independently associated with chronic asthma treatment prescription (aOR:2.724; CI 1.051-7.063, p:0.04) and with current asthma (aOR:3.41; CI 1.20-9.66, p:0.02). Nasal detection of periostin was associated with lower frequency of ever use of short-acting beta2-agonists (SABA) (p = 0.04), lower prevalence of current asthma (p = 0.02), less prescription of maintenance asthma treatment in the past 12 months (p = 0.02, respectively). In the multivariate analysis, periostin was associated with lower risk of asthma at 4 years, independently of the atopic status (aOR:0.511 CI 95% 0.284-0.918, p:0.025).

CONCLUSIONS

Our results show a positive correlation between nasal TSLP detection in severe bronchiolitis and the presence of current asthma, prescription of asthma maintenance treatment and respiratory admissions up to the age of 4 years. By contrast, we found a protective association between nasal periostin detection and current asthma at 4 years, ever diagnosis of asthma, maintenance asthma treatment prescription, and respiratory admissions.

Childhood blood eosinophils and symptoms of allergic disorders: a cross-sectional study in Southern China

PURPOSE

The relationship between childhood blood eosinophils and subtypes of allergic diseases remains understudied. This study aimed to examine the associations between childhood blood eosinophils and subtypes of asthma, rhinitis and dermatitis, as well as the modifying effect of age.

METHODS

We obtained concurrent blood cell counts and serum Immunoglobulin E (IgE) test results in 5026 children (0-13, years) from First Affiliated Hospital of Guangzhou Medical University from 2014 to 2019. Generalized additive models with multivariable adjustments were utilized to model the exposure-response relationship between eosinophils and allergic symptoms. The robustness of the association was assessed in two age categories (<6, 6-13 years).

RESULTS

The association of eosinophils with allergic asthma/rhinitis was positively nonlinear, with a plateau at levels of Q₄ (≥0.51, 10⁹/L). Conversely, exposure-response curves between eosinophils and the risk of non-allergic asthma and rhinitis were negatively linear, and especially, became statistically significant when levels of eosinophils were larger than Q₃ (≥0.30, 10⁹/L). Compared with their counterparts, school-aged children (6-13, years) with a higher level of blood eosinophils (≥0.35, 10⁹/L) were more likely to suffer from allergic asthma [relative excess risk due to interaction (RERI), 2.51; 95% CI, 1.24-3.78], allergic rhinitis (RERI, 2.79; 95% CI, 1.14-4.45) but not allergic dermatitis (RERI not significant).

CONCLUSION

Higher eosinophil counts were associated with the increased risk of allergic subtype symptoms and the decreased risk of non-allergic subtypes in children. Moreover, the associations between eosinophils and allergic asthma/rhinitis were accentuated in the school-aged child. These findings may contribute to providing novel insights for clinical administration relevance of allergic-related symptoms.Key messages:There was a positively nonlinear association between childhood eosinophils and allergic asthma/rhinitis.Age modified the associations between eosinophils and allergy-related outcomes. The associations of eosinophil with allergic asthma/rhinitis accentuated in the school-aged child (6-13, years).

Can serum periostin predict bronchopulmonary dysplasia in premature infants?

BACKGROUND

Bronchopulmonary dysplasia (BPD) is the most common morbidity complicating preterm birth and affects long-term respiratory outcomes. The objectives of this study were to establish whether serum periostin at birth, day of life (DOL) 28, and corrected 36 weeks' gestational age could be potential biomarkers for BPD.

METHODS

A total of 98 preterm Japanese infants born at <32 weeks and comparing 41 healthy controls born at term, were divided into BPD (n = 44) and non-BPD (n = 54) cohorts. Serum periostin levels were measured using an enzyme-linked immunosorbent assay.

RESULTS

Among 98 preterm infants, the median serum periostin levels at birth were higher with BPD (338.0 ng/mL) than without (275.0 ng/mL, P < 0.001). Multivariate analysis revealed that serum periostin levels at birth were significantly associated with BPD (P = 0.013). Serum periostin levels at birth with moderate/severe BPD (345.0 ng/mL) were significantly higher than those with non-BPD/mild BPD (283.0 ng/mL, P = 0.006).

CONCLUSIONS

Serum periostin levels were significantly correlated with birth weight and gestational age, and serum periostin levels at birth in BPD infants were significantly higher than that in non-BPD infants.

IMPACT

This study found higher serum periostin levels at birth in preterm infants subsequently diagnosed with bronchopulmonary dysplasia. It also emerged that serum periostin levels at birth significantly correlated with gestational age and birth weight. The mechanism by which serum periostin is upregulated in BPD infants needs further investigation.

Serum Periostin Level in Children with Asthma

OBJECTIVES

To determine the average serum periostin level in children with asthma between 6 and 16 y of age, and to find out if the levels correlated with markers of eosinophilic inflammation, asthma control, and severity.

METHODS

Children under follow-up at a tertiary care centre were enrolled. Children with conditions causing elevated serum periostin other than asthma, or history of systemic steroid use in the past 6 mo were excluded. Serum total IgE and periostin were estimated by ELISA.

RESULTS

The median (IQR) serum periostin level was 52.6 (45.4, 58.3) ng/mL. Levels did not vary with age, gender, duration of symptoms, positive family history, or history of exacerbations in the last 6 mo. There was no significant correlation with anthropometric parameters or their z scores, or markers of eosinophilic inflammation in blood including serum total IgE, eosinophil percentage or absolute eosinophil count. There was no difference in median periostin levels of children with different asthma symptom control or asthma severity.

CONCLUSIONS

In a group of 26 Indian children with physician-diagnosed asthma, serum periostin showed no significant correlation to markers of eosinophilic inflammation.

Biomarkers to Predict Response to Inhaled Corticosteroids and Long-Acting Muscarinic Antagonists in Adolescents and Adults with Mild Persistent Asthma

Rationale: Whether biomarkers can be used to predict response to inhaled corticosteroids (ICS) or long-acting muscarinic antagonists (LAMA) in mild persistent asthma is unclear. Objectives: In a prespecified exploratory analysis of a randomized clinical trial of 295 participants 12 years of age or older with uncontrolled mild persistent asthma, we sought to identify biomarkers of treatment response after 12 weeks of ICS (mometasone, 200 μg or 220 μg twice/d), LAMA (tiotropium, 5 μg/d), or placebo in adults (⩾18 yr) and adolescents (12-17 yr) separately. Methods: The primary outcome was a composite outcome of asthma control (treatment failure, asthma control days, and forced expiratory volume in 1 second [FEV₁]). Analyses examined type 2 inflammatory biomarkers and physiologic biomarkers. We assessed the area under the receiver operating characteristic curve (AUC) for response to ICS and LAMA (each versus placebo). An AUC of 0.5 suggests no discrimination, 0.7-0.8 is considered acceptable, more than 0.8-0.9 is considered excellent, and more than 0.9 is considered outstanding. Results: In 237 adults, sputum and blood eosinophil levels and fractional exhaled nitric oxide (Fe_NO) each predicted ICS response (AUCs: 0.61 [95% confidence interval (CI), 0.53-0.69], 0.64 [95% CI, 0.56-0.72], and 0.62 [95% CI, 0.54-0.70], respectively; all P < 0.01); the AUC for blood eosinophil levels and Fe_NO together was 0.66 (95% CI, 0.58-0.74; P < 0.001). In 58 adolescents, the number of positive aeroallergens and total serum immunoglobulin E each predicted ICS response (AUCs: 0.69 [95% CI, 0.52-0.85] and 0.73 [95% CI, 0.58-0.87], respectively; both P < 0.03); the AUC for both together was 0.73 (95% CI, 0.58-0.87; P = 0.003). After ipratropium bromide, FEV₁ reversibility predicted LAMA response in adults (AUC: 0.61 [95% CI, 0.53-0.69], P = 0.007) but not in adolescents. Conclusions: The AUCs of the type 2 inflammatory biomarkers and physiological biomarkers we examined may not be high enough to confidently identify individuals with asthma who respond to ICS and LAMA. However, our findings indicate that the biomarkers that predict response to ICS or LAMA may differ in adults versus adolescents with uncontrolled mild persistent asthma. Prospective, biomarker-stratified clinical trials are needed to confirm these findings and to identify first-line controllers tailored for each population.

T-high asthma phenotypes across life span

RATIONALE

In adults, personalised asthma treatment targets patients with T2-high and eosinophilic asthma phenotypes. It is unclear whether such classification is achievable in children.

OBJECTIVES

To define T2-high asthma with easily accessible biomarkers and compare resulting phenotypes across all ages.

METHODS

In the multicenter clinical ALL Age Asthma Cohort (ALLIANCE), 1125 participants (n=776 asthmatics, n=349 controls) were recruited and followed for 2 years (1 year in adults). Extensive clinical characterisation (questionnaires, blood differential count, allergy testing, lung function and sputum induction (in adults) was performed at baseline and follow-ups. Interleukin (IL)-4, IL-5 and IL-13 were measured after stimulation of whole blood with LPS or anti-CD3/CD28.

MEASUREMENTS AND MAIN RESULTS

Based on blood eosinophil counts and allergen-specific serum IgE antibodies (sIgE), patients were categorised into four mutually exclusive phenotypes: "Atopy-only", "Eosinophils-only", "T2-high" (eosinophilia+atopy) and "T2-low" (neither eosinophilia nor atopy). The T2-high phenotype was found across all ages, even in very young children in whom it persisted to a large degree even after 2 years of follow-up. T2-high asthma in adults was associated with childhood onset suggesting early origins of this asthma phenotype. In both children and adults, the T2-high phenotype was characterised by excessive production of specific IgE to allergens (p<0.0001) and, from school age onwards, by increased production of IL-5 after anti-CD3/CD28 stimulation of whole blood.

CONCLUSIONS

Using easily accessible biomarkers, patients with T2-high asthma can be identified across all ages delineating a distinct phenotype. These patients may benefit from therapy with biologicals even at younger age.

Serum periostin among infants with severe bronchiolitis and risk of developing asthma: A prospective multicenter cohort study

BACKGROUND

Infants hospitalized for bronchiolitis (severe bronchiolitis) are at high risk for developing childhood asthma. However, the pathobiological link between these conditions remains unclear. We examined the longitudinal relationship of periostin (an extracellular matrix protein upregulated in response to type 2 inflammation) during bronchiolitis with the subsequent development of asthma.

METHODS

In a 17-center prospective cohort study of infants (aged <1 year) with severe bronchiolitis, we measured the serum periostin level at hospitalization and grouped infants into 3 groups: low, intermediate, and high levels. We examined their association with asthma development by age 6 years and investigated effect modification by allergic predisposition (eg, infant's IgE sensitization).

RESULTS

The analytic cohort consists of 847 infants with severe bronchiolitis (median age, 3 months). Overall, 28% developed asthma by age 6 years. In the multivariable model adjusting for nine patient-level factors, compared to the low periostin group, the asthma risk was significantly higher among infants in the intermediate group (23% vs. 32%, OR 1.68, 95%CI 1.12-2.51, p = .01) and non-significantly higher in the high-level group (28%, OR 1.29, 95%CI 0.86-1.95, p = .22). In the stratified analysis, infants with IgE sensitization had a significantly higher risk for developing asthma (intermediate group, OR 4.76, 95%CI 1.70-13.3, p = .002; high group, OR 3.19, 95%CI 1.08-9.36, p = .04). By contrast, infants without IgE sensitization did not have a significantly higher risk (p > .15).

CONCLUSIONS

In infants with severe bronchiolitis, serum periostin level at bronchiolitis hospitalization was associated with asthma risk by age 6 years, particularly among infants with an allergic predisposition.

COVID-19 Pandemic–Related Reductions in Pediatric Asthma Exacerbations Corresponded with an Overall Decrease in Respiratory Viral Infections

Background

Respiratory viruses, air pollutants, and aeroallergens are all implicated in worsening pediatric asthma symptoms, but their relative contributions to asthma exacerbations are poorly understood. A significant decrease in asthma exacerbations has been observed during the coronavirus disease 2019 pandemic, providing a unique opportunity to study how major asthma triggers correlate with asthma activity.

Objective

To determine whether changes in respiratory viruses, air pollutants, and/or aeroallergens during the coronavirus disease 2019 pandemic were concomitant with decreased asthma exacerbations.

Methods

Health care utilization and respiratory viral testing data between January 1, 2015, and December 31, 2020, were extracted from the Children’s Hospital of Philadelphia Care Network’s electronic health record. Air pollution and allergen data were extracted from US Environmental Protection Agency public databases and a National Allergy Bureau–certified station, respectively. Pandemic data (2020) were compared with historical data.

Results

Recovery of in-person asthma encounters during phased reopening (June 6 to November 15, 2020) was uneven: primary care well and specialty encounters reached 94% and 74% of prepandemic levels, respectively, whereas primary care sick and hospital encounters reached 21% and 40% of prepandemic levels, respectively. During the pandemic, influenza A and influenza B decreased to negligible frequency when compared with prepandemic cases, whereas respiratory syncytial virus and rhinovirus infections decreased to low (though nonnegligible) prepandemic levels, as well. No changes in air pollution or aeroallergen levels relative to historical observations were noted.

Conclusions

Our results suggest that viral respiratory infections are a primary driver of pediatric asthma exacerbations. These findings have broad relevance to both clinical practice and the development of health policies aimed at reducing asthma morbidity.

Integrative Analysis Reveals a miRNA-mRNA Regulatory Network and Potential Causative Agents in the Asthmatic Airway Epithelium

Background

During asthma progression, the intricate molecular networks, including microRNA (miRNA) transcriptional regulation in airway epithelium, remain largely undefined. The abnormal expression of miRNAs in asthmatic airway epithelium is a recent and fast-growing area in developing diagnostic and therapeutic targets for asthma.

Material and Methods

Analyses were conducted to compare airway epithelial miRNAs and gene expression between patients with asthma and healthy subjects from three datasets (two for miRNAs expression profiles and one for gene expression profile). The interactions network between differentially expressed (DE)-miRNAs and mRNAs was further identified for functional analysis. To verify the involvement and functions of all the identified miRNAs in asthma, we constructed two cellular models of asthma. The most promising causal miRNA candidate, miR-1246, was examined in an in vitro system to explore its targets and roles in asthma pathophysiology.

Results

Through integrative analysis, we obtained six miRNAs with 31 validated target genes in airway epithelium associated with asthma. Next, we confirmed that these miRNAs were all associated with asthma progression by in vitro functional experiments. They may participate in eosinophilic inflammation (miR-92b-3p, miR-1246, miR-197-3p, and miR-124-5p) or remodeling (miR-197-3p, miR-193a-5p, miR-1246, and miR-92b-3p). Additionally, some other non-screened valuable miRNAs were also examined and identified (miR-21-5p and miR-19b-3p), and some detected in blood correlated with the disease status. Furthermore, we found that miR-1246 could directly target POSTN and influence epithelial-to-mesenchymal transition and fibrosis in airway epithelial cells.

Conclusion

We constructed a preliminary epithelial regulatory network in asthma based on six identified miRNAs and their valuable target genes. Candidate factors in the biological miRNA-mRNA network in airway epithelium may provide further information on the pathogenesis of asthma. Strikingly, among all screened miRNAs, miR-1246, which could interact with POSTN may have multifunctional effects in the course of asthma and be a promising agent for asthma treatment and molecular subtyping.

Rhinovirus Infection and Familial Atopy Predict Persistent Asthma and Sensitisation 7 Years after a First Episode of Acute Bronchiolitis in Infancy

Background: We set out to assess the risk factors for asthma outcome in a cohort of infants who experienced their first episode of acute bronchiolitis. Methods: A cohort of 222 infants who were included during a first episode of acute bronchiolitis was prospectively followed. Herein, we present the results of their assessments (symptom history, skin prick tests, specific IgE assay, respiratory function tests) at age seven. Results: Of the 68/222 (30.6%) children assessed at age seven, 15 (22.05%) presented with asthma and were mainly males (p = 0.033), 14 (20%) had respiratory allergies, 17 (25%) presented atopic dermatitis and none had a food allergy. Family history of atopy was associated with asthma and sensitisation to aeroallergens at age seven (p = 0.003, p = 0.007). Rhinovirus (hRV) infection and rhinovirus/respiratory syncytial virus (RSV) co-infection were significantly associated with asthma at age seven (p = 0.035, p = 0.04), but not with the initial severity of bronchiolitis. Eosinophil counts at ages three and seven were significantly higher in the asthmatics (p = 0.01, p = 0.046). Conclusion: Any infant, especially male, presenting a first episode of acute bronchiolitis due to hRV with a family history of atopy should be closely monitored via follow-up due to a higher risk for asthma at school age.

Association of serum periostin levels with clinical features in children with asthma

BACKGROUND

The aim of this study was to investigate the association of serum periostin levels with clinical features in children with asthma.

METHODS

Children with physician-diagnosed asthma who attended regularly to an outpatient pediatric allergy and asthma center were enrolled in the study along with control subjects. Asthma severity and control status of the patients were evaluated according to the recent GINA guidelines.

RESULTS

A total of 158 children (125 with asthma and 33 age- and sex-matched control subjects) with a median age of 10.2 years (range 5.9-17.0) were enrolled. Asthma severity was mild in 41 (32.8%), moderate in 63 (50.4%), and severe in 21 (16.8%) children. Children with asthma had significantly higher periostin levels than controls (53.1 ± 13.1 vs 43.0 ± 11.2 ng/mL, P < .001). The mean serum periostin levels in children with severe asthma (63.8 ± 10.8) were significantly higher than in children with moderate asthma (53.3 ± 12.7) and mild asthma (47.4 ± 11.1) (P < .001). Results of multivariable logistic regression analysis demonstrated an association between serum periostin levels and asthma severity in children (OR, 1.10; 95% CI, 1.04-1.15, P < .001). When analyzed for the best cut-off value with the highest combined sensitivity and specificity, a cut-off value of 52 ng/mL for serum periostin level was obtained with sensitivity, specificity, PPV, and NPV of 100%, 50%, 29%, and 100%, respectively.

CONCLUSION

Although serum periostin levels are higher in children with asthma, its diagnostic role in identifying children with severe asthma is limited.

Mechanisms and biomarkers of airway epithelial cell damage in asthma: A review

Bronchial asthma is a heterogeneous disease with complex pathological mechanisms representing different phenotypes, including severe asthma. The airway epithelium is a major site of complex pathological changes in severe asthma due, in part, to activation of inflammatory and immune mechanisms in response to noxious agents. Current imaging procedures are unable to accurately measure epithelial and airway remodeling. Damage of airway epithelial cells occurs is linked to specific phenotypes and endotypes which provides an opportunity for the identification of biomarkers reflecting epithelial, and airway, remodeling. Identification of patients with more severe epithelial disruption using biomarkers may also provide personalised therapeutic opportunities and/or markers of successful therapeutic intervention. Here, we review the evidence for ongoing epithelial cell dysregulation in the pathogenesis of asthma, the sentinel role of the airway epithelium and how understanding these molecular mechanisms provides the basis for the identification of candidate biomarkers for asthma prediction, prevention, diagnosis, treatment and monitoring.

Understanding the immunology of asthma: Pathophysiology, biomarkers, and treatments for asthma endotypes

Asthma is a common disease in paediatrics and adults with a significant morbidity, mortality, and financial burden worldwide. Asthma is now recognized as a heterogeneous disease and emerging clinical and laboratory research has elucidated understanding of asthma's underlying immunology. The future of asthma is classifying asthma by endotype through connecting discernible characteristics with immunological mechanisms. This comprehensive review of the immunology of asthma details the currently known pathophysiology and clinical practice biomarkers in addition to forefront biologic and targeted therapies for all of the asthma endotypes. By understanding the immunology of asthma, practitioners will be able to diagnose patients by asthma endotype and provide personalized, biomarker-driven treatments to effectively control patients' asthma.

Relationship between sputum periostin level and inflammatory asthma phenotypes in Egyptian patients

Introduction: Asthma is a common chronic inflammatory air way disease which poses a high disease burden worldwide. Asthma is a heterogenous disease with various phenotypes and endotypes. Refractory asthma requires new and personalized approaches to manage it effectively. Periostin is a promising biomarker that may help in predicting severity, prognosis and could be a therapeutic target. We aimed in this study to investigate periostin levels in the sputum of asthmatic Egyptian patients of inflammatory phenotypes and its relation to asthma severity.Subjects and methods: This study included 96 adult asthmatic patients; 48 patients with mild-to-moderate bronchial asthma, 48 patients with severe bronchial asthma according to ATS criteria and 10 healthy controls. All participants were subjected to full history taking and clinical examination; pulmonary function tests; skin prick test; induced-sputum analysis for inflammatory cells and periostin.Results: Sputum periostin concentrations were significantly higher in patients with asthma than in controls. Sputum periostin is strongly correlated with age and sputum TLC and inversely correlated with FEV1. It is correlated with sputum neutrophil count and sputum eosinophil percentage. Best cut off value for sputum periostin is >528.25 ng/ml to differentiate between mild-to-moderate and severe asthma.Conclusion: Sputum periostin levels provide a satisfying diagnostic accuracy in severe asthmatic with persistent airflow limitation than mild-to-moderate asthmatic adults. There is a modest positive correlation between sputum periostin and sputum eosinophilia.

Role of serum periostin in the management of asthma and its comorbidities

Type-2 airway inflammation is a major characteristic of asthma. Assessing its degree of severity is, therefore, essential in asthma management. Periostin, a matricellular protein belonging to the fasciclin family, is a key molecule linking type-2 airway inflammation and airway remodeling. Fortunately, periostin can be detected in the blood and used to provide sustaining airway information on type-2 inflammation and remodeling. Serum periostin is elevated in the eosinophilic/type 2 subtype of severe asthma, and its levels remain relatively stable and reflect genetic backgrounds. This suggests that serum periostin may serve as a marker of geno-endophenotype with type-2 airway inflammation and thus could be a predictive marker of the long-term prognosis of asthma under treatment. As expected, serum periostin is particularly elevated in comorbidities associated with the eosinophilic/type 2 subtype of severe asthma, including eosinophilic chronic rhinosinusitis, aspirin-exacerbated respiratory diseases, allergic bronchopulmonary aspergillosis, and eosinophilic granulomatosis with polyangiitis. Conversely, serum periostin levels are relatively lower in the overweight/obese. Serum periostin measurements may help to significantly improve the management of patients with severe asthma.

The Tempest: Difficult to Control Asthma in Adolescence

Severe asthma is associated with significant morbidity and is a highly heterogeneous disorder. Severe asthma in adolescence has some unique elements compared with the features of severe asthma a medical provider would see in younger children or adults. A specific focus on psychological issues and adherence highlights some of the challenges in the management of asthma in adolescents. Treatment of adolescents with severe asthma now includes 3 approved biologic phenotype-directed therapies. Therapies available to adults may be beneficial to adolescents with severe asthma. Research into predictors of specific treatment response by phenotypes is ongoing. Optimal treatment strategies are not yet defined and warrant further investigation.

Periostin: An emerging biomarker for allergic diseases

Periostin is a matricellular protein as well as an extracellular matrix (ECM) protein belonging to the fasciclin family. Periostin plays important roles as a matricellular protein in the setting of allergic diseases by binding to several integrins on various cells. Since periostin is induced mainly by IL-4 and IL-13, signature type 2 cytokines, and it is highly expressed in the subepithelial regions of many chronic allergic diseases, periostin has emerged as a novel biomarker reflecting type 2 inflammation in allergic diseases. It has, moreover, been revealed that periostin has characteristics different from other type 2 biomarkers such as eosinophil count and fractional exhaled nitric oxide (FeNO), reflecting fibrosis or tissue remodeling. From this, we may say that serum periostin is a "chronic" type 2 biomarker, whereas FeNO and possibly the eosinophil count are "acute" type 2 biomarkers. In contrast, it is still uncertain how we can apply periostin measurement to the use of biologics for allergic diseases. By examining the roles of periostin in allergy and the utility and potential of periostin in developing diagnostics against allergic diseases, it is hoped that in the near future, we can develop a new strategy to treat allergic patients.

Nitric Oxide and Biological Mediators in Pediatric Chronic Rhinosinusitis and Asthma

BACKGROUND

In the context of the so-called unified airway theory, chronic rhinosinusitis (CRS) and asthma may coexist. The inflammation underlying these conditions can be studied through the aid of biomarkers. Main body: We described the main biological mediators that have been studied in pediatric CRS and asthma, and, according to the available literature, we reported their potential role in the diagnosis and management of these conditions. As for CRS, we discussed the studies that investigated nasal nitric oxide (nNO), pendrin, and periostin. As for asthma, we discussed the role of fractional exhaled nitric oxide (feNO), the role of periostin, and that of biological mediators measured in exhaled breath condensate (EBC) and exhaled air (volatile organic compounds, VOCs).

CONCLUSION

Among non-invasive biomarkers, nNO seems the most informative in CRS and feNO in asthma. Other biological mediators seem promising, but further studies are needed before they can be applied in clinical practice.

Periostin concentration in exhaled breath condensate in children with mild asthma

OBJECTIVE

Periostin is considered to be a marker of eosinophilic inflammation in patients with asthma. However, there are no literature data on exhaled breath condensate (EBC) periostin level in pediatric patients with asthma. The aim of this study was to analyze EBC periostin concentration in children with mild asthma and to evaluate the potential usefulness of EBC periostin level as a biomarker for the disease.

METHODS

EBC and serum periostin concentrations were measured by enzyme-linked immunosorbent assay in 23 children with asthma and 23 healthy controls.

RESULTS

EBC periostin concentration was 250- to 780-fold lower than that found in serum. No significant differences between serum nor EBC periostin concentration in asthmatics and the control group were showed. The comparison between children with Th2 and non-Th2 type of asthma did not show significant differences in periostin concentration, both in serum and EBC. Serum periostin concentration inversely correlated with BMI and age not only in asthma patients but also in controls.

CONCLUSIONS

In children with mild asthma, periostin may be measured not only in serum but also in EBC. The low periostin level in patients with mild asthma and lack of difference between asthmatic subjects and controls indicate that EBC periostin may not be useful as an asthma biomarker in this group.

It's Time to Start Phenotyping Our Patients with Asthma

Advances in the management of pediatric asthma, including biologics, offer practitioners the ability to tailor therapies to individual patients. However, asthma treatment guidelines have not kept up with current studies. This review explores the current literature incorporating the use of phenotyping in pediatric patients with asthma to provide precision therapy. Biomarkers can be used to more accurately predict the development of asthma, identify features that may be associated with difficult-to-control or severe asthma, and forecast response to therapies. Biomarkers and other phenotypic data can also be helpful in patients with uncontrolled, severe asthma in the selection of a biologic therapy.

Roles of Periostin in Asthma

Periostin is a matricellular protein that is deeply involved in type-2/eosinophilic airway inflammation and remodeling in asthma. While its expression in airway epithelial cells is correlated with the thickness of airway basement membrane, more importantly, periostin can be detected stably in blood with little variability, reflecting airway type-2 inflammation and remodeling. As for a result, serum periostin can serve as a valuable marker to identify patients with type-2 severe asthma who are insensitive to inhaled corticosteroids, and consequently have the excess decline of pulmonary function with asthma exacerbations. Serum periostin may significantly help to improve management of patients with severe asthma.

Biomarkers in asthma: state of the art

Asthma is a heterogenous disease characterized by multiple phenotypes driven by different mechanisms. The implementation of precision medicine in the management of asthma requires the identification of phenotype-specific markers measurable in biological fluids. To become useful, these biomarkers need to be quantifiable by reliable systems, reproducible in the clinical setting, easy to obtain and cost-effective. Using biomarkers to predict asthma outcomes and therapeutic response to targeted therapies has a great clinical significance, particularly in severe asthma. In the last years, significant research has been realized in the identification of valid biomarkers for asthma. This review focuses on the existent and emerging biomarkers with clinical higher applicability in the management of asthma.

Asthma is associated with carotid arterial injury in children: The Childhood Origins of Asthma (COAST) Cohort

BACKGROUND

Asthma is associated with an increased cardiovascular disease (CVD) risk in adults, but the impact of asthma and atopic conditions on CVD risk in children is less well established. We hypothesized that children in the Childhood Origins of Asthma (COAST) Cohort with asthma and atopic conditions would have early carotid arterial injury.

METHODS

The COAST study is a longitudinal birth cohort of children at increased risk of developing asthma. Children underwent ultrasonography measuring far wall right carotid bifurcation (RCB) and common carotid artery (RCCA) intima-media thickness (IMT; a measure of arterial injury). Multivariable linear regression models adjusted for age, gender, race, blood pressure, and body-mass index were used to assess associations of asthma and markers of arterial injury.

RESULTS

The 89 participants were a mean (standard deviation) 15.3 (0.6) years old and 42% were female; 28 asthmatics had atopic disease, 34 asthmatics were without other atopic disease, and 15 non-asthmatics had atopic disease. This study population was compared to 12 controls (participants free of asthma or atopic disease). Compared to controls (589 μm), those with atopic disease (653 μm, p = 0.07), asthma (649 μm, p = 0.05), or both (677 μm, p = 0.005) had progressively higher RCB IMT values (ptrend = 0.011). In adjusted models, asthmatic and/or atopic participants had significantly higher RCB IMT than those without asthma or atopic disease (all p≤0.03). Similar relationships were found for RCCA IMT.

CONCLUSION

Adolescents with asthma and other atopic diseases have an increased risk of subclinical arterial injury compared to children without asthma or other atopic disease.

Advances in asthma in 2017: Mechanisms, biologics, and genetics

This review summarizes some of the most significant advances in asthma research over the past year. We first focus on novel discoveries in the mechanism of asthma development and exacerbation. This is followed by a discussion of potential new biomarkers, including the use of radiographic markers of disease. Several new biologics have become available to the clinician in the past year, and we summarize these advances and how they can influence the clinical delivery of asthma care. After this, important findings in the genetics of asthma and heterogeneity in phenotypes of the disease are explored, as is the role the environment plays in shaping the development and exacerbation of asthma. Finally, we conclude with a discussion of advances in health literacy and how they will affect asthma care.

Disconnect of type 2 biomarkers in severe asthma; dominated by FeNO as a predictor of exacerbations and periostin as predictor of reduced lung function

BACKGROUND

biomarkers of Type 2 (T2) inflammation may predict asthma control and exacerbation risk. However, the relationships between individual T2 biomarkers to exacerbations and lung function in severe asthma remain uncertain.

OBJECTIVES

to explore the roles played by T2 biomarkers individually and as a composite score in predicting clinical outcomes in severe asthma.

METHODS

unselected severe asthma patients were enrolled in this cross sectional real life study. Participants were clinically characterised and the following measurements were obtained: the frequency of exacerbations requiring oral corticosteroids (OCS), asthma control (Juniper ACQ6-7), lung function, Fraction exhaled Nitric Oxide (FeNO), peripheral blood eosinophils (PBE), and serum periostin.

RESULTS

A total of 115 patients were recruited [mean age 45 years (range 18-70), 80 (69.6%) females, mean forced expiratory volume in first second (FEV₁) %predicted was 68% ± 24.7, mean inhaled corticosteroids (ICS) 1.96 ± 0.82 mg/day. FeNO correlated significantly with PBE (r = 0.35, p = 0.0004), but not with periostin (r = 0.22, p = 0.065) and there was no significant correlation between PBE and periostin. FeNO correlation with exacerbations (r = 0.42, p = 0.0008) was stronger than PBE and periostin. A composite score of the 3 biomarkers correlated with exacerbations in a dose-dependent manner but multiple regression analysis did not confirm an added benefit. Only periostin demonstrated a significant correlation with FEV₁%predicted (r = -0.34, p = 0.004) with ROC-AUC 0.7.

CONCLUSION

FeNO demonstrated stronger correlation with asthma exacerbations than PBE or periostin with no definite added benefit from a composite score of the 3 biomarkers. Only periostin showed significant association with reduced lung function raising its potential as a biomarker of airway remodeling.

Serum periostin levels following small bone fractures, long bone fractures and joint replacements: an observational study

BACKGROUND

In asthma, serum periostin may potentially be used as a biomarker in the management of patients with Type-2 eosinophilic airway inflammation. However, serum periostin may be influenced by factors other than Type 2 inflammation, potentially confounding its interpretation. We aimed to measure change in periostin following bone injury.

METHODS

102 adults without asthma were recruited into three groups: joint replacement surgery, long bone fracture, short bone fracture. Participants underwent seven measurements of serum periostin over 26 weeks after bone injury, and prior to surgery in the joint replacement group. Differences in periostin were measured using a ratio of geometric mean (RGM), with comparison made with pre-surgery (joint replacement) or 26 week (long and short fracture) reference measurements.

RESULTS

In the joint replacement group, periostin fell within 48 h (RGM 0.80, 95% CI 0.75-0.86), then increased to a maximum at 8 weeks (RGM 1.89, 1.77-2.02) and by 26 weeks remained above the reference measurement (RGM 1.27, 1.19-1.36). In the long bone fracture group, periostin was reduced at 48 h (RGM 0.76, 0.71-0.83) and then progressively increased to a maximum at 8 weeks (RGM 1.15, 1.06-1.23) compared with the reference measurement. In the short bone fracture group, periostin was reduced at 48 h (RGM 0.9, 0.85-0.95) but was not different from after week 1 compared with the reference measurement.

CONCLUSIONS

Serum periostin levels are influenced by bone injury. The timing and extent of bone injury needs consideration if periostin is used as a biomarker in the management of eosinophilic asthma.Trial registration This trial was prospectively registered with the Australia New Zealand Trials Registry on Feb 7 2014, (ACTRN12614000151639: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=363881).

Increased expression of serum periostin and YKL40 in children with severe asthma and asthma exacerbation

Children with severe asthma or acute asthma exacerbation may encounter difficulties in performing pulmonary function tests. In this situation, serum biomarkers can play a great role in evaluation of such patients. The aim of this study was to estimate the serum levels of human chitinase-3-like protein 1 (YKL40) and periostin in a group of Egyptian children with asthma during acute asthma exacerbation and in stable asthmatics compared with healthy control, and to correlate these findings with the severity of asthma. This cross-sectional study enrolled 120 childrenwith asthma with different degrees of asthma severity, according to the Global Initiative for Asthma guidelines, along with 60 age-matched and sex-matched healthy control. A complete blood count and an estimation of serum periostin and YKL40 levels were performed for all cases and control. Individual and mean values of periostin and YKL40 were significantly higher during acute asthma exacerbations, p<0.001. A highly significant relation between serum levels of periostin and YKL40 and asthma severity, p value for each was <0.001. Absolute eosinophil count was significantly correlated with the serum periostin levels in stable asthmatic group (p=0.01) only. There was significantly positive correlation (P<0.001) between both markers in stable asthmatic group. Spearman's correlation coefficient shows a statistically significant positive correlation between both markers and patient's age and duration of asthma, p value for each was 0.001. These findings highlight the importance of periostin and YKL40 as serum biomarkers for assessment of asthma severity and acute asthma exacerbations in children with asthma.

Serum periostin is not related to asthma predictive index

BACKGROUND

In contrast to adult asthmatic patients, studies on the role of serum periostin levels in schoolchildren with asthma are still conflictive, and very few studies have been performed in pre-schoolers. The aim of this study was to compare serum periostin levels in recurrent wheezer pre-schoolers according to their asthma predictive index (API) condition.

METHODS

We performed a case-control study enrolling pre-schoolers with recurrent wheezing episodes (>3 episodes confirmed by physician) presented at one paediatric clinic in Santiago, Chile. The population was divided according to stringent API criteria into positive or negative.

RESULTS

In a one-year period, 60 pre-schoolers were enrolled. After excluding 12 (due to not fulfilment of inclusion criteria or refusal of blood sample extraction), 48 remaining pre-schoolers (27 males, age range from 24 to 71 months) completed the study; 34 were API positive and 14 were API negative. There were no significant differences in demographics between groups. The level of serum periostin levels for pre-schoolers with positive API and negative API were (median 46.7 [25.5-83.1] and 67.5 [20.5-131.8], p=0.9, respectively). The area under the curve for the serum periostin levels for predict positive API was 0.5, 95% CI [0.29-0.70], p=0.9. No significant correlation between serum periostin levels and peripheral blood eosinophils was found.

CONCLUSION

Serum periostin levels were no significantly different between wheezer pre-schoolers with positive and negative API. More studies are needed to confirm this finding.

Baseline asthma burden, comorbidities, and biomarkers in omalizumab-treated patients in PROSPERO

BACKGROUND

Patients included in clinical trials do not necessarily reflect the real-world population.

OBJECTIVE

To understand the characteristics, including disease and comorbidity burden, of patients with asthma receiving omalizumab in a real-world setting.

METHODS

The Prospective Observational Study to Evaluate Predictors of Clinical Effectiveness in Response to Omalizumab (PROSPERO) was a US-based, multicenter, single-arm, and prospective study. Patients (≥12 years of age) with allergic asthma initiating omalizumab treatment based on physician-assessed need were included and followed for 12 months. Exacerbations, health care use, adverse events, and Asthma Control Test (ACT) scores were assessed monthly. Biomarkers (blood eosinophils, fractional exhaled nitric oxide, and periostin) were evaluated and patient-reported outcomes (Asthma Quality of Life Questionnaire for 12 Years and Older [AQLQ+12] and Work Productivity and Activity Impairment: Asthma questionnaire [WPAI:Asthma]) were completed at baseline and months 6 and 12. The Mini Rhinoconjunctivitis Quality of Life Questionnaire (MiniRQLQ) was completed at baseline and 12 months.

RESULTS

Most of the 806 enrollees (91.4%) were adults (mean age 47.3 years, SD 17.4), white (70.3%), and female (63.5%). Allergic comorbidity was frequently reported (84.2%), as were hypertension (35.5%) and depression (22.1%). In the 12 months before study entry, 22.1% of patients reported at least 1 asthma-related hospitalization, 60.7% reported at least 2 exacerbations, and 83.3% reported ACT scores no higher than 19 (uncontrolled asthma). Most patients had low biomarker levels based on prespecified cut-points. Baseline mean patient-reported outcome scores were 4.0 (SD 1.4) for AQLQ+12, 2.7 (SD 1.4) for MiniRQLQ, and 47.7 (SD 28.9) for WPAI:Asthma percentage of activity impairment and 33.5 (SD 28.7) for percentage of overall work impairment.

CONCLUSION

The population initiating omalizumab in PROSPERO reported poorly controlled asthma and a substantial disease burden.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01922037.

Eosinophils and eosinophil-associated diseases: An update

The goal of this series is to offer a survey of the latest literature for clinicians and scientists alike, providing a list of important recent advances relevant to the broad field of allergy and immunology. This particular assignment was to cover the topic of eosinophils. In an attempt to highlight major ideas, themes, trends, and advances relevant to basic and clinical aspects of eosinophil biology, a search of articles published since 2015 in the Journal of Allergy and Clinical Immunology and other high-impact journals was performed. Articles were then reviewed and organized, and then key findings were summarized. Given space limitations, many outstanding articles could not be included, but the hope is that what follows provides a succinct overview of recently published work that has significantly added to our knowledge of eosinophils and eosinophil-associated diseases.

Severe therapy resistant asthma in children: translational approaches to uncover sub-phenotypes

INTRODUCTION

Paediatric severe therapy resistant asthma (STRA) affects a very small proportion of all children with asthma, but results in significant morbidity, has a high risk of mortality and utilises approximately half of all healthcare resources for childhood asthma. children with STRA need add-on 'beyond guidelines' therapies because of poor control despite maximal conventional treatments and optimisation of basic asthma management. however, STRA is heterogeneous with marked phenotypic variation between patients and mechanisms from adult severe asthma cannot be extrapolated to children. Areas covered: This review will cover our current knowledge of paediatric STRA pathophysiology, with examples of translational approaches that have been used to define sub-phenotypes including; 1. pre-clinical age-appropriate models using clinically relevant allergens, 2. in vitro techniques incorporating complex co-cultures of structural and inflammatory cells, and 3. techniques that allow detailed cellular immunophenotyping of small airway samples will be discussed. Studies using these approaches that have demonstrated the importance of the innate mediator IL-33 and vitamin D deficiency in severe steroid resistant disease will also be discussed. Expert commentary: These experimental approaches allow investigation of age and disease specific molecular pathways and the development of personalised therapies that can be stratified and targeted to sub-phenotypes of paediatric STRA.

Biomarkers in inflammometry pediatric asthma: utility in daily clinical practice

Asthma is a common disease in both high and lower income countries that starts early and persists often for life. A correct and accurate diagnosis, treatment and follow-up during childhood are essential for a better understanding of adult asthma and avoiding over- or under-treatment. Th2 inflammation in children with asthma symptoms is usually assessed by measuring with serum total IgE, blood eosinophilia and FeNO levels that may help to predict asthma, particularly in those infants and young children in whom lung function tests are difficult to perform. FeNO measurement, compared to intra-individual levels, may be useful also for ascertaining treatment adherence. Nevertheless, an isolated measurement may be insufficient and only the combination of these markers improves the diagnosis, phenotyping and follow-up of an asthmatic child.

Severe Asthma in Children

PURPOSE OF REVIEW

The aim of this study is to characterize, diagnose, evaluate, and treat severe childhood asthma.

RECENT FINDINGS

Understanding the occurrence of the physiologic and clinical presentations of childhood severe asthma, the treatment and response may be predicted by biomarkers, but the patient's response is highly variable. The onset of severe asthma occurs early and is primarily predicted by severity of viral infection and coexistence of the atopic state.

Corticosteroid Therapy During Acute Bronchiolitis in Patients Who Later Develop Asthma

BACKGROUND AND OBJECTIVE

Meta-analyses show that corticosteroids are not effective in patients with bronchiolitis. However, risk factors for asthma such as eczema or familial atopy prompt some practitioners to prescribe corticosteroids for bronchiolitis. We assessed if corticosteroid prescription is associated with shorter hospitalization for bronchiolitis among patients who later develop asthma.

METHODS

The Pediatric Health Information System database was interrogated for patients with bronchiolitis aged <2 years hospitalized between 2006 and 2015. Only patients who also later had a hospitalization for asthma and prescription of inhaled corticosteroids were included. For the initial bronchiolitis admission, use of mechanical ventilation defined "severe illness," and ICU admission without mechanical ventilation defined "moderate illness"; all other patients were deemed to have "mild illness." Variables associated (P < .10) with length of stay (LOS) in bivariate analysis were included in linear regression analysis.

RESULTS

During the bronchiolitis admission of 2479 children who were later hospitalized for asthma, corticosteroid prescription (n = 857) was associated with longer LOS in bivariate analysis (3 [2-4] vs 2 [2-4] days; P < .01) but not the multivariate model (P = .18) that included age, sex, comorbid conditions, bacterial pneumonia, and illness severity. Corticosteroid prescription was associated with shorter LOS among previously healthy children with moderate illness (4 [2-6] vs 5 [3-7] days; P = .02) but not those with mild or severe illness.

CONCLUSIONS

Corticosteroids were not associated with improved outcome in patients with bronchiolitis who were later hospitalized with asthma. Moderately ill patients with no comorbidities may warrant further study.

The Role of Sensitization to Allergen in Asthma Prediction and Prevention

The burden of asthma in childhood is considerable worldwide, although some populations are much more affected than others. Many attempts have been made by different investigators to identify the factors that could predict asthma development or persistence in childhood. In this review, the relation between atopic sensitization as an indicator of allergy and asthma in childhood will be discussed. Cross sectional studies, carried out in different countries, failed to show any firm correlation between asthma and atopic sensitization. Birth cohort mainly of infants at high risk for asthma and case-control studies showed that atopic sensitization was a risk factor for current asthma in children older than 6 years. In general, clear relations are observed mostly in affluent Western countries, whereas in less affluent countries, the picture is more heterogeneous. For the prediction of asthma development or persistence in school age children, other prerequisites should also be fulfilled such as family history of asthma and wheezing episodes at preschool age. Despite the conductance of different studies regarding the potential role of allergen avoidance for the primary prevention of childhood asthma, it does not seem that this approach is of benefit for primary prevention purposes. However, the identification of children at risk for asthma is of benefit as these subjects could be provided with the best management practices and with the appropriate secondary prevention measures.

Biomarkers for the Phenotyping and Monitoring of Asthma in Children

An important issue in relation to the utility and reliability of biomarkers for asthma monitoring is how asthma is defined and characterized. What kind of asthma, or at what stage of the disease is a particular biomarker supposed to add information? Often, the purpose, or usefulness of a biomarker is not made clear. Diagnosis, severity evaluation, and monitoring are all different clinical uses for a biomarker, and confusion may arise when a biomarker is suitable for one of these but not another. When the utility of available biomarkers are discussed, these different roles need to be clarified. Our opinion is that there are four aspects of relevance to asthma, for which biomarkers are required: to diagnose allergies, to evaluate inflammation in the airways, to evaluate hyper-responsiveness, and for certain measures of lung function, such as lung clearance index. These types of biomarkers are needed for the phenotyping and monitoring of asthma. Another important role for biomarkers is, as mentioned above, to monitor asthma in order to follow treatment effects on inflammation and hyper-responsiveness as objective adjuncts to the patients' own symptom reports and lung function. This review will mainly focus on biomarkers that reflect airway inflammation. In spite of the numerous studies that have been conducted, we still have to remember that the value of biomarkers available for routine use, such as eosinophil counts in blood and sputum and exhaled nitric oxide, have to be interpreted in relation to reported symptoms and lung function. Measures of bronchial hyper-responsiveness, performed either by direct (methacholine challenge) or indirect (exercise or mannitol challenge) methods, could be considered biomarkers but will not be included in this review. On the other hand, diagnosing allergy is not usually useful for monitoring asthma although it is of fundamental importance for the interpretation of most biomarkers that are suitable for monitoring. We have therefore included the different approaches for diagnosing and evaluating allergic sensitization in this review.