Advances in pediatric asthma in 2013: coordinating asthma care

Autophagy related gene 5 polymorphism rs17587319 (C/G) in asthmatic patients in North Indian population

Objective: Genetic background and environmental stimuli play an important role in asthma, which is an individual's hyper-responsiveness to these stimuli leading to airway inflammation. Autophagy Related Gene 5 (ATG5) plays a critical role in the autophagy pathway and has been shown to be involved in asthma. The genetic polymorphisms in the ATG5 have been reported to predispose individuals to asthma. The role of single nucleotide polymorphism rs17587319 (C/G) of ATG5 in asthma has not been studied so far. Materials and methods: In this study, we in silico analysed rs17587319 (C/G) using web-based tools Human Splice Finder (HSF) and RegulomeDB and further a case-control study was conducted that included 187 blood samples (94 asthmatic and 93 healthy controls). Results: In silico analysis suggested alteration of splicing signals by this intronic variant. The samples were genotyped by applying the PCR-RFLP method. The MAF obtained was 0.022 and 0.043 in healthy controls and asthmatic individuals, respectively. The statistical analysis revealed no association (allelic model, OR = 2.02, 95%CI = 0.59-6.83, p = 0.25; co-dominant model, OR = 2.06, 95%CI = 0.6-7.12, p = 0.24) of rs17587319 (C/G) with the susceptibility to asthma in the north Indian population. Conclusions: In conclusion, rs17587319 (C/G) of ATG5 does not predispose individuals to asthma in our part of the world. Further studies are needed including more number of samples to ascertain the role of this polymorphism in asthma.

MicroRNA-335-5p alleviates inflammatory response, airway fibrosis, and autophagy in childhood asthma through targeted regulation of autophagy related 5

Childhood asthma is the most universal chronic disease, with significant cases reported. Despite the current progress in treatment, prognosis remains poor and the existing drugs cause serious side effects. This investigation explored the mechanisms and use of miR-335-5p on childhood asthma therapy. MiR-335-5p and ATG5 expression was analyzed in clinical plasma samples through RT-qPCR. Airway smooth muscle cells (ASMCs) were cultured, and transfected with miR-335-5p mimic, miR-335-5p inhibitor, and pcDNA3.1-ATG5, or co-transfected with miR-335-5p mimic + pcDNA3.1-ATG5. Asthma cell models were constructed through TGF-β1, and animal models through ovalbumin (OVA). Monocyte-macrophage infiltration in bronchoalveolar lavage fluid (BALF) was determined by May-Grunwald-Giemsa staining, and collagen in lung tissue was assessed via Masson staining. Relationship between miR-335-5p and ATG5 was detected by dual-luciferase assay. Cell proliferation was detected by MTT assay. MiR-335-5p and ATG5 RNA expression was determined by RT-qPCR. Collagen I, collagen III, α-SMA, ATG5, LC3I/II, Beclin-1, and p62 protein expression levels in ASMCs were detected by western blot. MiR-335-5p expression was low, but ATG5 expression was high in childhood asthma. Versus OVA+ mimic NC group, the number of eosinophil and collagen in OVA+ miR-335-5p mimic group were reduced. In contrast to TGF-β1 + mimic NC group, TGF-β1 + miR-335-5p mimic group reduced inflammatory, airway fibrosis, and autophagy in ASMCs. ATG5 was miR-335-5p target. Overexpressing ATG5 significantly reversed the inhibitory effects of miR-335-5p on inflammatory response, fibrosis, and autophagy in ASMCs. Overall, the study concludes that MiR-335-5p alleviate inflammatory response, airway fibrosis, and autophagy in childhood asthma through targeted regulation of ATG5.

Ten year trends in hospital encounters for pediatric asthma: an Indiana experience

INTRODUCTION

Pediatric asthma is a common cause of emergency department visits, hospital admissions, and mortality. Population incidence studies have historically used large-scale survey data. We measured these epidemiologic trends using a health information exchange.

METHODS

In this retrospective cohort study, we used electronic health record data from a regional health information exchange to study clinical trends in pediatric patients presenting to the hospital for asthma in the State of Indiana. Data was obtained from 2010 to 2019 and included all patients ages 2-18 years. Study participants were identified using international classification of disease codes. The measured outcomes were number of hospital encounters per year, percentage of admissions per year, and mortality rates.

RESULTS

Data included 50,393 unique patients and 88,772 unique encounters, with 57% male patients. Over the ten-year period, hospital encounters ranged from 5000 to 8000 per year with no change in trajectory. Between 2010 and 2012, the percent of encounters admitted to the hospital was ∼30%. This decreased to ∼20-25% for 2015-2019. Patient mortality rates increased from 1 to 3 per 1000 patient encounters in 2010-2014 to between 5 and 7 per 1000 patient encounters from 2016 to 2019. White patients had a significantly higher admission percentage compared to other racial groups, but no difference in mortality rate.

CONCLUSIONS

Asthma continues to be a common condition requiring hospital care for pediatric patients. Regional health information exchanges can enable public health researchers to follow asthma trends in near real time, and have potential for informing patient-level public health interventions.

MicroRNA-744 Inhibits Proliferation of Bronchial Epithelial Cells by Regulating Smad3 Pathway via Targeting Transforming Growth Factor-β1 (TGF-β1) in Severe Asthma

BACKGROUND Bronchial epithelial cells proliferation plays a pivotal role in airway remodeling in children with severe asthma. MicroRNAs (miRNAs) have gained great attention for many diseases, including asthma. The purpose of this study was to explore the mechanisms that underlie miR-744 modulating bronchial epithelial cells proliferation in severe asthma in children. MATERIAL AND METHODS Bronchial epithelial cells were isolated from bronchial biopsies of normal controls and asthmatic subjects. miR-744 and transforming growth factor-ß1 (TGF-ß1) expressions were measured by quantitative reverse transcription PCR (qRT-PCR). Proliferating cell nuclear antigen (PCNA), phosphorylation or total of mothers against decapentaplegic homolog3 (Smad3) and production of Smad anchor for receptor activation (SARA) were measured via Western blot analysis. A link between miR-744 and TGF-ß1 was probed by luciferase activity and RNA immunoprecipitation. Cell proliferation was evaluated using the Cell Proliferation Assay Kit. RESULTS Severe asthma showed a significantly elevated cell proliferation rate and reduced abundance of miR-744, which in turn inhibited cell proliferation of bronchial epithelial cells. In particular, TGF-ß1 might be a candidate target of miR-744, and enrichment of miR-744 lowered the expression of TGF-ß1 at mRNA and protein levels. Indeed, overexpression of miR-744 lowered the proliferation rate of bronchial epithelial cells via driving TGF-ß1. Moreover, addition of miR-744 limited phosphorylation of Smad3 but reversed SARA protein abundance by regulating TGF-ß1. CONCLUSIONS The presence of miR-744 repressed bronchial epithelial cells proliferation through mediating the Smad3 pathway by modulating TGF-ß1, providing a promising therapeutic approach for epithelial function in severe asthma.

A Clinical Pathway for the Care of Critically Ill Patients With Asthma in the Community Hospital Setting

OBJECTIVES

The management of severe pediatric asthma exacerbations is variable. The use of clinical pathways has been shown to decrease time to clinical recovery and length of stay (LOS) for critically ill patients with asthma in freestanding children's hospitals. We sought to determine if implementing a clinical pathway for pediatric patients who are on continuous albuterol in a community hospital would decrease time to clinical recovery and LOS.

METHODS

A clinical pathway for guiding the initiation, escalation, and weaning of critical asthma therapies was adapted to a community hospital without a PICU. There were 2 years of baseline data collection (from September 2014 to August 2016) and 16 months of intervention data collection. Segmented regression analysis of interrupted time series was used to evaluate the pathway's impact on LOS and time to clinical recovery.

RESULTS

There were 129 patients in the study, including 69 in the baseline group and 60 in the intervention group. After pathway implementation, there was an absolute reduction of 10.2 hours (SD 2.0 hours) in time to clinical recovery (P ≤ .001). There was no significant effect on LOS. There was a significant reduction in the transfer rate (27.5% of patients in the baseline period versus 11.7% of patients in the intervention period; P = .025). There was no increase in key adverse events, which included the percentage of patients who required ICU-specific therapies while awaiting transfer (7.3% of patients in the baseline period versus 1.7% of patients in the intervention period; P = .215).

CONCLUSIONS

The implementation of a clinical pathway for the management of critically ill children with asthma and on continuous albuterol in a community hospital was associated with a significant reduction in time to clinical recovery without an increase in key adverse events.

Budesonide and Calcitriol Synergistically Inhibit Airway Remodeling in Asthmatic Mice

Background and Objective

While calcitriol can inhibit airway remodeling in asthmatic mice, the mechanism remains unclear. The purpose of this study was to explore the mechanism of action of calcitriol on airway remodeling in asthma and its interaction with budesonide.

Methods

A mouse model of asthma was established by allergic sensitization and challenge with ovalbumin. The mice were treated with budesonide, calcitriol, or budesonide plus calcitriol. The expression of airway remodeling-related proteins, transforming growth factor β (TGFβ) signaling pathway-related proteins, the glucocorticoid receptor, and vitamin D receptor (VDR) was determined by immunohistochemical staining and Western blot analysis. Quantitative real-time PCR was used to determine the expression of microRNA-21 (miR-21) in the lung tissue of mice.

Results

Monotherapy with budesonide or calcitriol inhibited the high expression of collagen type I protein and upregulated the low expression of Smad7 in asthmatic mice. There was a synergistic interaction between budesonide and calcitriol in combined treatment. The expression of miR-21 in the combined treatment group was significantly lower than that in the calcitriol treatment group. VDR expression in the combined treatment group was significantly higher than that of the calcitriol treatment group.

Conclusion

Budesonide and calcitriol have a synergistic effect on airway remodeling in asthmatic mice.

Expression and Regulation of Thymic Stromal Lymphopoietin and Thymic Stromal Lymphopoietin Receptor Heterocomplex in the Innate-Adaptive Immunity of Pediatric Asthma

Asthma is a chronic inflammatory disease affecting the airway, and it is characterized by a wheezing breathing sound, variable airflow obstruction and the presence of inflammatory cells in the submucosa of the bronchi. Viral infection, pollutants and sensitivity to aeroallergens damage the epithelium from childhood, which causes asthma. The pathogenesis of asthma includes pathways of innate stimulation by environmental microbes and irritant pathogens. Damaged epithelial cells produce thymic stromal lymphopoietin (TSLP) and stimulate myeloid dendritic cell maturation through the thymic stromal lymphopoietin receptor (TSLPR) heterocomplex. TSLP-activated myeloid dendritic cells promote naive CD4⁺ T cells to differentiate into T helper type 2 (Th2) phenotype CD4⁺ T cells. Re-exposure to allergens or environmental stimuli causes an adaptive immune response. TSLP-activated dendritic cells expressing the OX40 ligand (OX40L; CD252) trigger naive CD4⁺ T cells to differentiate into inflammatory Th2 effector cells secreting the cytokines interleukin-4, 5, 9, and 13 (IL-4, IL-5, IL-9 and IL-13), and the dendritic cells (DCs) promote the proliferation of allergen-specific Th2 memory cells. Allergen presentation by Th2 cells through its interaction with their receptors in the presence of major histocompatibility complex (MHC) class II on B cells and through costimulation involving CD40 and CD40L interactions results in immunoglobulin class switching from IgM to IgE. DCs and other blood cell subsets express the TSLPR heterocomplex. The regulatory mechanism of the TSLPR heterocomplex on these different cell subsets remains unclear. The TSLPR heterocomplex is composed of the IL-7Rα chain and TSLPR chain. Moreover, two isoforms of TSLP, short isoform TSLP (sfTSLP) and long isoform TSLP (lfTSLP), have roles in atopic and allergic development. Identifying and clarifying the regulation of TSLPR and IL-7Rα in pediatric asthma are still difficult, because the type of blood cell and the expression for each blood cell in different stages of atopic diseases are poorly understood. We believe that further integrated assessments of the regulation mechanism of the TSLP–TSLPR heterocomplex axis in vitro and in vivo can provide a faster and earlier diagnosis of pediatric asthma and promote the development of more effective preventive strategies at the onset of allergies.

Therapeutic effects of liver soothing pingchuan formula decoction on experimental asthma in BALB/c mice via regulation of nerve growth factor-tyrosine kinase A pathway

The present study was designed to investigate the effects of liver soothing pingchuan formula decoction (LSPF) on experimental asthma in BALB/c mice and explore its potential molecular mechanisms. An animal model of asthma was established in BALB/c mice through sensitization and activation with intraperitoneal injection of 10% ovalbumin (OVA)/Al(OH)3 solution in addition to inhalation of a 5% OVA solution. LSPF (300 and 600 mg/kg/day) was initially administered orally prior to activation. Following this, bronchoalveolar lavage fluid (BALF) and lung tissues were collected for histopathalogical examination. Levels of inflammatory cells and cytokines were determined in the BALF, and levels of nerve growth factor (NGF) and tyrosine kinase A (TrkA) in the lung tissues were determined. The results of the present study indicated that increased inflammatory reactions were observed following OVA sensitization (P<0.05), and the expression levels of NGF (P<0.05) and TrkA (P<0.05) were significantly increased, compared with normal mice. Notably, compared with the asthma model group, immunohistochemical results revealed that LSPF treatment suppressed OVA induced inflammatory reactions (P<0.05) and NGF (P<0.05) and TrkA expression levels (P<0.05). In addition, the NGF (P<0.05) and TrkA (P<0.05) were revealed to be downregulated with LSPF treatment from the results of the ELISA and western blotting assay. Overall, the results of the present study demonstrated that LSPF exhibits therapeutic effects on experimental asthma in mice, via downregulation of the NGF-TrkA pathway.

Rhinovirus-induced first wheezing episode predicts atopic but not nonatopic asthma at school age

Background

Persistent childhood asthma is mainly atopy driven. However, limited data exist on the risk factors for childhood asthma phenotypes.

Objective

We sought to identify risk factors at the first severe wheezing episode for current asthma 7 years later and separately for atopic and nonatopic asthma.

Methods

One hundred twenty-seven steroid-naive children with the first severe wheezing episode (90% hospitalized/10% emergency department treated) were followed for 7 years. The primary outcome was current asthma at age 8 years, which was also analyzed separately as atopic and nonatopic asthma. Risk factors, including sensitization, viral cause, and other main asthma risk factors, were analyzed.

Results

At study entry, median age was 11 months (interquartile range, 6-16 months); 17% were sensitized, and 98% were virus positive. Current asthma (n = 37) at 8 years was divided into atopic (n = 19) and nonatopic (n = 18) asthma. The risk factors for current atopic asthma at study entry were sensitization (adjusted odds ratio [OR], 12; P < .001), eczema (adjusted OR, 4.8; P = .014), and wheezing with rhinovirus (adjusted OR, 5.0; P = .035). The risk factors for nonatopic asthma were the first severe respiratory syncytial virus/rhinovirus–negative wheezing episode (adjusted OR, 8.0; P = .001), first wheezing episode at age less than 12 months (adjusted OR, 7.3; P = .007), and parental smoking (adjusted OR, 3.8; P = .028).

Conclusions

The data suggest diverse asthma phenotypes and mechanisms that can be predicted by using simple clinical markers at the time of the first severe wheezing episode. These findings are important for designing early intervention strategies for secondary prevention of asthma.

THE CLINICAL EFFICACY OF SUBLINGUAL ALLERGEN-SPECIFIC IMMUNOTHERAPY IN CHILDREN AGED 3-5 YEARS

The aim of this study was to determine the efficacy of sublingual allergen–specific immunotherapy (SLIT) in Ukrainian children younger than 5 years old with allergic rhinitis and bronchial asthma sensitized to house dust mite allergens. Material and methods: Four hundred and fifty children aged 28 months up to 5 years with rhinitis or asthma were examined. One hundred and twenty five children sensitized to house dust mites Dermatophagoides pteronyssinus and/or Dermatophagoides farina were included. In vivo and in vitro tests were made with a standard inhalant allergens panel. Results: The high information value of molecular diagnostics methods applied prior to prescription of the given therapy in children is analyzed. It has been found that in children under 5 sensitized to allergens of house dust mites Dermatophagoides pteronyssinus and/or Dermatophagoides farinae the application of sublingual allergen–specific immunotherapy therapy allows gaining control over the symptoms of the disease during the first 6 months. Conclusion: The high safety of SLIT in children has been proven. Comparative analysis in the group of patients not receiving SLIT shows a high frequency of symptoms of the disease after “free-of-symptoms interval” against full or partial baseline therapy denial.

A systematic review of predictive models for asthma development in children

BACKGROUND

Asthma is the most common pediatric chronic disease affecting 9.6 % of American children. Delay in asthma diagnosis is prevalent, resulting in suboptimal asthma management. To help avoid delay in asthma diagnosis and advance asthma prevention research, researchers have proposed various models to predict asthma development in children. This paper reviews these models.

METHODS

A systematic review was conducted through searching in PubMed, EMBASE, CINAHL, Scopus, the Cochrane Library, the ACM Digital Library, IEEE Xplore, and OpenGrey up to June 3, 2015. The literature on predictive models for asthma development in children was retrieved, with search results limited to human subjects and children (birth to 18 years). Two independent reviewers screened the literature, performed data extraction, and assessed article quality.

RESULTS

The literature search returned 13,101 references in total. After manual review, 32 of these references were determined to be relevant and are discussed in the paper. We identify several limitations of existing predictive models for asthma development in children, and provide preliminary thoughts on how to address these limitations.

CONCLUSIONS

Existing predictive models for asthma development in children have inadequate accuracy. Efforts to improve these models' performance are needed, but are limited by a lack of a gold standard for asthma development in children.

Effect of high-dose sublingual immunotherapy on respiratory infections in children allergic to house dust mite

Background

Allergic rhinitis is characterized by eosinophil inflammation. Allergic inflammation may induce susceptibility to respiratory infections (RI). House dust mite (HDM) sensitization is very frequent in childhood. Allergen immunotherapy may cure allergy as it restores a physiologic immune and clinical tolerance to allergen and exerts anti-inflammatory activity.

Objective

This study investigated whether six-month high-dose, such as 300 IR (index of reactivity), HDM-sublingual immunotherapy (SLIT) could affect RI in allergic children.

Methods

Globally, 40 HDM allergic children (18 males; mean age, 9.3 years) were subdivided in 2 groups: 20 treated by symptomatic drugs (group 1) and 20 by high-dose HDM-SLIT (group 2), since September 2012 to April 2013. The daily maintenance dose of HDM-SLIT was 4 pressures corresponding to 24, 4.8, and 60 µg, respectively of the major allergens Dermatophagoides pteronyssinus (Der p) 1, Der p 2, and Dermatophagoides farinae (Der f) 1. RI was diagnosed when at least 2 symptoms or signs, and fever were present for at least 48 hours. A family pediatrician provided diagnosis on a clinical ground.

Results

SLIT-treated children had significantly (p = 0.01) less RI episodes (3.5) than control group (5.45). About secondary outcomes, SLIT-treated children had less episodes of pharyngo-tonsillitis (p < 0.05) and bronchitis (p < 0.005), and snoring (p < 0.05) than control group. In addition, SLIT-treated children had less fever (p < 0.01) and took fewer medications, such as antibiotics (p < 0.05) and fever-reducers (p < 0.01), than control group.

Conclusion

This preliminary study might suggest that also a short course (6 months) of high-dose SLIT, titrated in µg of major allergens, could reduce RI in allergic children.

Advances in adult asthma diagnosis and treatment in 2014

In 2014, new biologic therapies are emerging for severe asthma based on identification of relevant phenotypes. The exploration of nutritional supplements to treat asthma has been less successful.

Using public policy to improve outcomes for asthmatic children in schools

School-based services to improve asthma management need to be accompanied by public policies that can help sustain services, scale effective interventions, create greater equity across schools, and improve outcomes for children. Several national organizations, including the Centers for Disease Control and Prevention, have recommended specific public policies the adoption of which in school settings can improve asthma outcomes for children. Although many states and school districts have adopted some of these policies, adoption is not universal, and implementation is not always successful, leaving inequities in children's access to asthma services and supports. These issues can be addressed by changing public policy. Policy change is a complex process, but it is one that will benefit from greater involvement by asthma experts, including the researchers who generate the knowledge base on what services, supports, and policies have the best outcomes for children. Asthma experts can participate in the policy process by helping to build awareness of the need for school-based asthma policy, estimating the costs associated with policy options and with inaction, advocating for the selection of specific policies, assisting in implementation (including providing feedback), conducting the research that can evaluate the effectiveness of implementation, and ultimately providing information back into the policy process to allow for improvements to the policies.

Advances in pediatric asthma in 2014: Moving toward a population health perspective

Last year's "Advances in pediatric asthma in 2013: Coordinating asthma care" concluded that, "Enhanced communication systems will be necessary among parents, clinicians, health care providers and the pharmaceutical industry so that we continue the pathway of understanding the disease and developing new treatments that address the unmet needs of patients who are at risk for severe consequences of unchecked disease persistence or progression." This year's summary will focus on further advances in pediatric asthma related to prenatal and postnatal factors altering the natural history of asthma, assessment of asthma control, and new insights regarding the management of asthma in children as indicated in Journal of Allergy and Clinical Immunology publications in 2014. A major theme of this review is how new research reports can be integrated into medical communication in a population health perspective to assist clinicians in asthma management. The asthma specialist is in a unique position to convey important messages to the medical community related to factors that influence the course of asthma, methods to assess and communicate levels of control, and new targets for intervention, as well as new immunomodulators. By enhancing communication among patients, parents, primary care physicians, and specialists within provider systems, the asthma specialist can provide timely information that can help to reduce asthma morbidity and mortality.

Clinical and biological markers of asthma control

Asthma has substantial impact on the patient, their family and health systems, and its control has gained increasing attention. Perception of asthma control has varied widely among patients as well as healthcare providers. Several clinical markers have been developed to define and standardize the measurement of asthma control. They are based primarily on patients' symptoms and have been popular in clinical practice and in clinical studies. With the advances in basic research on the pathology of asthma, several biological markers have evolved that have the advantages of being objective, quantitative and more reflective of the underlying pathology, which makes them a better guide for selecting optimal therapy. In addition to the cost and expertise required, biological makers are influenced by multiple factors that limit their application in clinical practice. Ongoing research is expected to define the role of individual biological markers, the optimal method of their application, and their appropriate interpretation.

Trends in racial disparities for asthma outcomes among children 0 to 17 years, 2001-2010

BACKGROUND

Racial disparities in childhood asthma have been a long-standing target for intervention, especially disparities in hospitalization and mortality.

OBJECTIVES

Describe trends in racial disparities in asthma outcomes using both traditional population-based rates and at-risk rates (based on the estimated number of children with asthma) to account for prevalence differences between race groups.

METHODS

Estimates of asthma prevalence and outcomes (emergency department [ED] visits, hospitalizations, and deaths) were calculated from national data for 2001 to 2010 for black and white children. Trends were calculated using weighted loglinear regression, and changes in racial disparities over time were assessed using Joinpoint.

RESULTS

Disparities in asthma prevalence between black and white children increased from 2001 to 2010; at the end of this period, black children were twice as likely as white children to have asthma. Population-based rates showed that disparities in asthma outcomes remained stable (ED visits and hospitalizations) or increased (asthma attack prevalence, deaths). In contrast, analysis with at-risk rates, which account for differences in asthma prevalence, showed that disparities in asthma outcomes remained stable (deaths), decreased (ED visits, hospitalizations), or did not exist (asthma attack prevalence).

CONCLUSIONS

Using at-risk rates to assess racial disparities in asthma outcomes accounts for prevalence differences between black and white children, and adds another perspective to the population-based examination of asthma disparities. An at-risk rate analysis shows that among children with asthma, there is no disparity for asthma attack prevalence and that progress has been made in decreasing disparities in asthma ED visit and hospitalization rates.