Predicting asthma outcomes

Airway epithelial overexpressed cathepsin K induces airway remodelling through epithelial-mesenchymal trophic unit activation in asthma

BACKGROUND AND PURPOSE

Airway epithelial cells (AECs) regulate the activation of epithelial-mesenchymal trophic units (EMTUs) during airway remodelling through secretion of signalling mediators. However, the major trigger and the intrinsic pathogenesis of airway remodelling is still obscure.

EXPERIMENTAL APPROACH

The differing expressed genes in airway epithelia related to airway remodelling were screened and verified by RNA-sequencing and signalling pathway analysis. Then, the effects of increased cathepsin K (CTSK) in airway epithelia on airway remodelling and EMTU activation were identified both in vitro and in vivo, and the molecular mechanism was elucidated in the EMTU model. The potential of CTSK as an an effective biomarker of airway remodelling was analysed in an asthma cohort of differing severity. Finally, an inhibitor of CTSK was administered for potential therapeutic intervention for airway remodelling in asthma.

KEY RESULTS

The expression of CTSK in airway epithelia increased significantly along with the development of airway remodelling in a house dust mite (HDM)-stressed asthma model. Increased secretion of CTSK from airway epithelia induced the activation of EMTUs by activation of the PAR2-mediated pathway. Blockade of CTSK inhibited EMTU activation and alleviated airway remodelling as an effective intervention target of airway remodelling.

CONCLUSION AND IMPLICATIONS

Increased expression of CTSK in airway epithelia is involved in the development of airway remodelling in asthma through EMTU activation, mediated partly through the PAR2-mediated signalling pathway. CTSK is a potential biomarker for airway remodelling, and may also be a useful intervention target for airway remodelling in asthma patients.

Pediatric asthma comorbidities: Global impact and unmet needs

Real-world data on the range and impact of comorbid health conditions that affect pediatric asthma are scant, especially from developing countries. Lack of data hinders effective diagnosis, treatment, and overall management of these complex cases. We, hereby, describe the common pediatric asthma comorbid conditions in terms of evidence for association, potential mechanisms of impact on asthma control, and treatment benefit. Obesity, upper airway allergies, dysfunctional breathing, multiple sensitizations, depressive disorders, food allergy, and gastro-esophageal reflux are common associations with difficult-to-treat asthma. On the other hand, asthma symptoms and/or management may negatively impact the well-being of children through drug adverse effects, worsening of anaphylaxis symptoms, and disturbing mental health. Awareness of these ailments may be crucial for designing the optimum care for each asthmatic child individually and may ultimately improve the quality of life of patients and their families. A multidisciplinary team of physicians is required to identify and manage such comorbidities aiming to mitigate the over-use of asthma pharmacotherapy. Asthma research should target relevant real-world difficulties encountered at clinical practice and focus on interventions that would mitigate the impact of such comorbidities. Finally, policymakers and global healthcare organizations are urged to recognize pediatric asthma control as a healthcare priority and allocate resources for research and clinical interventions. In other words, global asthma control needs support by compassionate scientific partnership.

Bacteria and viruses and their role in the preschool wheeze to asthma transition

Wheezing is the cardinal symptom of asthma; its presence early in life, mostly caused by viral infections, is a major risk factor for the establishment of persistent or recurrent disease. Early-life wheezing and asthma exacerbations are triggered by common respiratory viruses, mainly rhinoviruses (RV), and to a lesser extent, respiratory syncytial virus, parainfluenza, human metapneumovirus, coronaviruses, adenoviruses, influenza, and bocavirus. The excess presence of bacteria, several of which are part of the microbiome, has also been identified in association with wheezing and acute asthma exacerbations, including haemophilus influenza, streptococcus pneumoniae, moraxella catarrhalis, mycoplasma pneumoniae, and chlamydophila pneumonia. While it is not clear when asthma starts, its characteristics develop over time. Airway remodeling already appears between the ages of 1 and 3 years of age even prior to the presence of atopic inflammation or an asthma diagnosis. The role of genetic defect or variations hampering the airway epithelium in response to environmental stimuli and severe disease morbidity are now considered as major determinants for early structural changes. Repeated viral infections can induce and perpetuate airway hyperresponsiveness. Allergic sensitization, that often precedes infection-induced wheezing, shifts inflammation toward type-2, while common respiratory infections themselves promote type-2 inflammation. Nevertheless, most children who wheeze with viral infections during infancy and during preschool years do not develop persistent asthma. Multiple factors, including illness severity, viral etiology, allergic sensitization, and the exposome, are associated with disease persistence. Here, we summarize current knowledge and developments in infection epidemiology of asthma in children, describing the known impact of each individual agent and mechanisms of transition from recurrent wheeze to asthma.

Emergency management and asthma risk in young Medicaid-enrolled children with recurrent wheeze

OBJECTIVES

To describe clinical characteristics of young children presenting to the emergency department (ED) for early recurrent wheeze, and determine factors associated with subsequent persistent wheeze and risk for early childhood asthma.

METHODS

Retrospective cohort study of Medicaid-enrolled children 0-3 years old with an index ED visit for wheeze (e.g. bronchiolitis, reactive airway disease) from 2009 to 2013, and at least one prior documented episode of wheeze at an ED or primary care visit. The primary outcome was persistent wheeze between 4 and 6 years of age. Demographics and clinical characteristics were collected from the index ED visit. Logistic regression was used to estimate the association between potential risk factors and subsequent persistent wheeze.

RESULTS

During the study period, 41,710 children presented to the ED for recurrent wheeze. Mean age was 1.3 years; 59% were male, 42% Black, and 6% Hispanic. At index ED visits, the most common diagnosis was acute bronchiolitis (40%); 77% of children received an oral corticosteroid prescription. Between 4 and 6 years of age, 11,708 (28%) children had persistent wheeze. A greater number of wheezing episodes was associated with an increased odds of ED treatment with asthma medications. Subsequent persistent wheeze was associated with male sex, Black race, atopy, prescription for bronchodilators or corticosteroids, and greater number of visits for wheeze.

CONCLUSIONS

Young children with persistent wheeze are at risk for childhood asthma. Thus, identification of risk factors associated with persistent wheeze in young children with recurrent wheeze might aid in early detection of asthma and initiation of preventative therapies.

Circulating CC16 and Asthma: A Population-based, Multicohort Study from Early Childhood through Adult Life

Rationale: Club cell secretory protein (CC16) is an antiinflammatory protein highly expressed in the airways. CC16 deficiency has been associated with lung function deficits, but its role in asthma has not been established conclusively. Objectives: To determine 1) the longitudinal association of circulating CC16 with the presence of active asthma from early childhood through adult life and 2) whether CC16 in early childhood predicts the clinical course of childhood asthma into adult life. Methods: We assessed the association of circulating CC16 and asthma in three population-based birth cohorts: the Tucson Children's Respiratory Study (years 6-36; total participants, 814; total observations, 3,042), the Swedish Barn/Children, Allergy, Milieu, Stockholm, Epidemiological survey (years 8-24; total participants, 2,547; total observations, 3,438), and the UK Manchester Asthma and Allergy Study (years 5-18; total participants, 745; total observations, 1,626). Among 233 children who had asthma at the first survey in any of the cohorts, baseline CC16 was also tested for association with persistence of symptoms. Measurements and Main Results: After adjusting for covariates, CC16 deficits were associated with increased risk for the presence of asthma in all cohorts (meta-analyzed adjusted odds ratio per 1-SD CC16 decrease, 1.20; 95% confidence interval [CI], 1.12-1.28; P < 0.0001). The association was particularly strong for asthma with frequent symptoms (meta-analyzed adjusted relative risk ratio, 1.40; 95% CI, 1.24-1.57; P < 0.0001), was confirmed for both atopic and nonatopic asthma, and was independent of lung function impairment. After adjustment for known predictors of persistent asthma, children with asthma in the lowest CC16 tertile had a nearly fourfold increased risk for having frequent symptoms persisting into adult life compared with children with asthma in the other two CC16 tertiles (meta-analyzed adjusted odds ratio, 3.72; 95% CI, 1.78-7.76; P < 0.0001). Conclusions: Circulating CC16 deficits are associated with the presence of asthma with frequent symptoms from childhood through midadult life and predict the persistence of asthma symptoms into adulthood. These findings support a possible protective role of CC16 in asthma and its potential use for risk stratification.

Association of body mass index with asthma occurrence and persistence in adolescents: A retrospective study of NHANES (2011-2018)

Objective

To investigate the association of body mass index (BMI) with asthma and analyze the risk factors of asthma persistence among overweight/obese adolescents and those with a high risk for obesity.

Methods

In this cross-sectional study, adolescents aged 11-17 years with complete general information and asthma diagnoses were selected from the National Health and Nutrition Examination Survey database. For adolescents without self-reported asthma, we performed matching according to age and sex at a case-to-control ratio of 1:3. Logistic regression analysis was employed to identify independent predictors of asthma occurrence followed by constructing a nomogram and comparing its efficacy to independent factors in predicting asthma occurrence. Besides, associations of BMI with asthma occurrence and persistence were evaluated. Finally, we obtained risk factors for asthma persistence in overweight/obese individuals and those at a high risk for obesity.

Results

Totally 753 adolescents with asthma and 2259 adolescents without asthma were included to analyze the occurrence of asthma. BMI and Hispanic Ethnicity were independent predictors of asthma occurrence and were included in nomogram construction. BMI had an efficiency comparable to that of the nomogram model in predicting asthma occurrence, which is superior to that of Hispanic Ethnicity. Of the 753 adolescents diagnosed with asthma, 464 were still diagnosed with asthma of at least a year's duration. Interestingly, BMI may have the ability to predict asthma persistence. Further, Hispanic Ethnicity and household income were significantly related to asthma occurrence among overweight/obese and high-risk obese individuals.

Conclusions

High BMI could independently predict increased asthma occurrence. Additionally, BMI may play an essential role in predicting asthma persistence. This study may help improve the diagnosis and reduce the occurrence of asthma.

Associations between peer experiences and health outcomes among adolescents and young adults with asthma

OBJECTIVE

Although peer relationships become increasingly important across adolescence and early adulthood, research examining links between peer relationships and the health outcomes of young people with asthma is scarce. Using a large sample of adolescents and young adults (AYAs) with asthma, the current study assessed whether positive and negative peer experiences are associated with AYAs' asthma control, asthma self-efficacy, and internalizing symptoms.

METHODS

In this cross-sectional study, a national sample of 440 diverse adolescents and young adults with asthma completed an online survey. Questionnaires assessed general and asthma-specific peer experiences (i.e. peer victimization; peer support; asthma-related peer problems) and health indicators (i.e. asthma control; asthma self-efficacy; internalizing symptoms). Regression analyses were performed to examine associations between peer experiences and health while controlling for participant age, gender, race/ethnicity, and age of asthma diagnosis.

RESULTS

Results from separate regression models indicated that adolescents who experienced greater peer victimization, less peer support, and more asthma-related peer problems also reported worse asthma control, lower asthma self-efficacy, and more severe internalizing symptoms. Follow-up exploratory analyses indicated that peer victimization and asthma-related peer problems were the strongest predictors of asthma control and internalizing, whereas peer support and asthma-related peer problems were the strongest predictors of asthma self-efficacy.

CONCLUSIONS

This study underscores connections between peer relationships and health outcomes among AYAs with asthma. Interventions that leverage peer support and mitigate peer stress may offer a developmentally appropriate approach for mitigating physical and psychological distress among adolescents and young adults with asthma.

Loss of control in preschoolers with asthma is a risk factor for disease persistency

AIM

To describe the relationship between loss of control events in preschoolers with asthma and persistence of disease.

METHODS

We reviewed medical records of children <6 years diagnosed with asthma in 2018 to assess loss of control events during three years of follow-up. Asthma persistency was defined by redeem of short-acting β2-agonist or asthma controllers within one year after the end of follow-up. Logistic regression models were applied to analyse the association between loss of control events and persistence of asthma.

RESULTS

We included 172 patients (median age 1.8 years), whereof 126 (73.3%) experienced a loss of control event and 87 (50.6%) had asthma one year after the end of follow-up. Any loss of control event was associated with persistence of asthma adjusted for controller treatment at inclusion, prior exacerbations, atopic comorbidity and caesarean section: aOR, 10.9 (95% CI, 3.9-34.6), p < 0.001. This was also significant restricted to events in the first year of follow-up: 3.52 (1.50-8.67), p < 0.01 and among children only experiencing one event: 6.4 (1.7-27.3), p = 0.01.

CONCLUSION

Loss of control events during a 3-year period among preschoolers with asthma are closely related to disease persistency, which may aid clinicians to assess risk of persistent asthma in young children.

Airway epithelial ITGB4 deficiency induces airway remodeling in a mouse model

BACKGROUND

Airway epithelial cells (AECs) with impaired barrier function contribute to airway remodeling through the activation of epithelial-mesenchymal trophic units (EMTUs). Although the decreased expression of ITGB4 in AECs is implicated in the pathogenesis of asthma, how ITGB4 deficiency impacts airway remodeling remains obscure.

OBJECTIVE

This study aims to determine the effect of epithelial ITGB4 deficiency on the barrier function of AECs, asthma susceptibility, airway remodeling, and EMTU activation.

METHODS

AEC-specific ITGB4 conditional knockout mice (ITGB4^-/-) were generated and an asthma model was employed by the sensitization and challenge of house dust mite (HDM). EMTU activation-related growth factors were examined in ITGB4-silenced primary human bronchial epithelial cells of healthy subjects after HDM stimulation. Dexamethasone, the inhibitors of JNK phosphorylation or FGF2 were administered for the identification of the molecular mechanisms of airway remodeling in HDM-exposed ITGB4^-/- mice.

RESULTS

ITGB4 deficiency in AECs enhanced asthma susceptibility and airway remodeling by disrupting airway epithelial barrier function. Aggravated airway remodeling in HDM-exposed ITGB4^-/- mice was induced through the enhanced activation of EMTU mediated by Src homology domain 2-containing protein tyrosine phosphatase 2/c-Jun N-terminal kinase/Jun N-terminal kinase-dependent transcription factor/FGF2 (SHP2/JNK/c-Jun/FGF2) signaling pathway, which was partially independent of airway inflammation. Both JNK and FGF2 inhibitors significantly inhibited the aggravated airway remodeling and EMTU activation in HDM-exposed ITGB4^-/- mice.

CONCLUSIONS

Airway epithelial ITGB4 deficiency induces airway remodeling in a mouse model of asthma through enhanced EMTU activation that is regulated by the SHP2/JNK/c-Jun/FGF2 pathway.

Persistent Asthma at School Age: Associated Factors in Preschool Children with Asthma

Most patients with childhood asthma present their first symptoms at preschool age. Identifying modifiable risks and protective factors at an early age may help develop asthma prevention and control strategies. This study aimed to identify factors at preschool age that are associated with persistent asthma at school age. This retrospective observational study included preschool children with asthma from 2015 to 2020 at a university hospital in Southern Thailand. In total, 189 eligible participants (70.9% boys; median age, 7.6 [6.7, 8.5] years) were included. Wheeze characteristics included early transient wheeze, persistent wheeze, and late-onset wheeze that accounted for 55%, 27.5%, and 19.5% of the patients, respectively. Approximately 20% of the participants had persistent asthma. Breastfeeding was a protective factor (odds ratio [OR] 0.4 [0.2, 0.9], p = 0.04). The modifiable risk factors were siblings living in the same household (OR 2.6 [1.1, 6.2], p = 0.02) and residence in an industrial area (OR 3.8 [1.4, 10.5], p = 0.009). Additionally, presence of allergic rhinitis was associated with an increased risk of persistent asthma at school age (OR 3.6 [1.6, 8.2], p = 0.002). Early therapeutic interventions targeting modifiable factors provide a window of opportunity to prevent persistent asthma at school age.

Predictive characteristics to discriminate the longitudinal outcomes of childhood asthma: a retrospective program-based study

BACKGROUND

Childhood asthma is an inflammatory disease with heterogeneous outcomes. We sought to determine the impact of total IgE, blood eosinophil, allergen sensitization, and inhaled corticosteroid (ICS) on longitudinal outcomes and to identify characteristics for discriminating different outcomes.

METHODS

We conducted a retrospective study in 383 childhood asthma patients and another 313 patients with blood eosinophil data only receiving regular program-based visits from September 1, 2004, to December 31, 2018. Peak expiratory flow (PEF) variability, PEF predicted %, asthma severity, and asthma control at each visit were assessed as clinical outcomes.

RESULTS

Our data show that the percentage of blood eosinophils was significantly associated with increased asthma severity (OR: 1.043, 95% CI: 1.002-1.086, P = 0.0392). Mold sensitization was significantly associated with asthma severity (OR: 2.2485, 95% CI: 1.3253-3.8150, P = 0.0027). Characteristics including sensitization status plus ICS dosage had the best area under the receiver operating characteristic curve (AUC) value for predicting longitudinal PEF predicted % (0.6609), PEF variability (0.6885), asthma severity (0.5918), and asthma control (0.6441), respectively.

CONCLUSIONS

We showed that the risk for adverse clinical outcomes at follow-up differed between serum IgE, blood eosinophil, and allergen sensitization identified at baseline. Sensitization and ICS dosage were predictive characteristics of long-term clinical outcomes.

IMPACT

The unique aspects of the study are its longitudinal assessment of patients receiving guideline-based asthma management program to help characterize the stability of the clinical outcomes over time. Characteristics including allergen sensitization and ICS dosage demonstrated an improved capability for distinguishing between better and worse clinical outcomes. Through longitudinal serial assessment, this study indicates the risk for adverse clinical outcomes differed between children with serum IgE/blood eosinophil/allergen sensitization characterized at baseline.

Adolescent and young adult allergic asthma treatment challenges

The transition from paediatric care to adult care is often difficult, especially in children with chronic diseases like asthma. A significant number of children reach remission throughout puberty; consequently, they are not tracked down for subsequent follow-ups and are not included in transition programmes to adult care. This case report focuses on a young adult with asthma that began in childhood and went into remission during adolescence, only to experience a recurrence when the patient was a young adult. Due to failing to complete the transition process into adult care services, she had poor adherence to therapy and asthma control.Adherence and asthma control significantly improved after a multidisciplinary approach in an adult care setting. In conclusion, appropriate transition and a multidisciplinary approach are critical for the effective management of asthma in young adults.

Bacterial composition and colony structure of the lower respiratory tract in infants and children with recurrent wheezing: a case-control study

BACKGROUND

The bacterial load of the human lower respiratory tract is at least several times lower than that of the other parts of the body. This study aimed to identify the bacterial composition and colony structure of the lower respiratory tract in infants and children with recurrent wheezing compared with those of children with a bronchial foreign body and clarify whether the length of wheezing in infants can contribute to differences in the lower respiratory tract's bacterial colony structure.

METHODS

We collected specimens of alveolar lavage fluid from 48 infants and children who underwent fiberoptic bronchoscopy and were divided into groups: A1 (multiple wheezing: wheezing more than three times in < 1 month), A2 (persistent wheezing: > 1 month), and B (bronchial foreign body; control group). We analyzed the bacterial community structure of alveolar lavage fluid using high-throughput sequencing. The richness and diversity of the microbial communities were assessed by α and β diversity analyses.

RESULTS

A total of 6,644 operational taxonomic units (OTUs) were obtained based on the Illumina Nova sequencing platform and clustered according to those that met the 97% identity threshold, followed by species annotation of the OTU sequences. In the annotation results, 2,608 (39.25%) OTUs were annotated at the genus level. At the genus level, Sphingomonas and Phyllobacterium were significantly higher in group A1 than in group B. There were significantly more Phyllobacterium in group A2 than in group B. Prevotella, Neisseria, and Haemophilus were higher in group B than in groups A1 and A2. The differences in the between-group α and β diversity analyses were statistically significant. The microbial diversity in groups A1 and A2 was significantly less than that in group B, but there was no statistical difference in bacterial community diversity between groups A1 and A2.

CONCLUSION

Recurrent wheezing in infants and children is more likely due to alterations in the overall bacterial microecology and disruption of host respiration and immune homeostasis than the effects of a single bacterium.

Allergic Rhinitis and House Dust Mite Sensitization Determine Persistence of Asthma in Children

OBJECTIVE

To specify clinical and immunological parameters of the mechanisms, which may lead to development of persistent asthma, or regression of the disease symptoms.

METHODS

Eighty children with childhood asthma, diagnosed in the past by using the modified Asthma Predicted Index (mAPI), were divided into two groups: remission group and persistent group. There were 3 study visits (baseline, at 6 mo, and at 12 mo). Clinical remission of asthma was defined as the absence of asthma symptoms for at least 12 mo without treatment. The patients could switch from one group to another during the 12 mo of follow-up. Clinical, inflammatory, and immunoregulatory predictors of asthma remission/persistence were analyzed.

RESULTS

The presence of mAPI criteria as well as house dust mite (HDM) allergy and allergic rhinitis at 7-10 y, were associated with a reduced prevalence of asthma remission. The increased eosinophil blood count in mAPI criteria was associated with a lower expression of CD25 positive cells. HDM allergy was associated with a higher fractional exhaled nitric oxide (FeNO) level (p = 0.0061) and higher expression of CD25CD71 (p = 0.0232). Allergic rhinitis was associated with a higher expression of PPAR (p = 0.0493) and CD25CD71 (p = 0.0198), and lower expression of glycoprotein A repetitions predominant (GARP).

CONCLUSIONS

Persistence of childhood asthma was largely determined by the presence of allergic rhinitis and sensitization to HDM. Additionally, API criteria but not immunoregulation processes, were related to asthma persistence.

Predicting the course of asthma from childhood until early adulthood

PURPOSE OF REVIEW

To communicate recent insights about the natural history of childhood asthma, with a focus on prediction of persistence and remission of childhood asthma, up to early adulthood.

RECENT FINDINGS

Lung function around the age of 8-9 years is the strongest predictor: obstructive lung function predicts asthma persistence up to early adulthood, whereas normal lung function predicts remission. The ability to predict asthma remission improves when lung function is combined with blood eosinophil levels and degree of bronchial hyperresponsiveness. Interventions, such as inhaled corticosteroids and immunotherapy do not appear to alter the course of asthma. Epigenetic studies have revealed potential novel biomarkers of asthma remission, such as micro-RNA patterns in blood. Specifically, lower serum levels of mi-R221-5p, which is associated with lower IL-6 release and eosinophilic inflammation, predict remission. Higher levels of blood DNA-methylation of a CpG site in Peroxisomal Biogenesis Factor 11 Beta were associated with asthma remission.

SUMMARY

Lung function, allergic comorbidity and polysensitization in childhood predict the course of asthma. Recent epigenetic studies have provided a better understanding of underlying pathological processes in asthma remission, which may be used to improve prediction or develop novel treatments aimed at altering the course of asthma.

Maintenance of Asthma Control in Adolescents with Severe Asthma After Transitioning to a Specialist Adult Centre: A French Cohort Experience

Background

The prevalence of severe asthma in adolescents is estimated at 6.7%. Transition to adult health services is a vulnerable period for adolescents where there is a risk of poor treatment adherence and loss to follow-up.

Purpose

This retrospective study evaluated the maintenance of asthma control in young severe asthmatics, 6 months and 1 year after transition to a specialist adult centre.

Methods

Patients with severe asthma treated in a paediatric pulmonology centre in the Île-de-France and referred at least 6 months previously to an adult service were included. Asthma control was evaluated by measuring the ACT score and respiratory function. Patients were asked to answer an on-line questionnaire about their experiences during transition.

Results

Fifty-four adolescents with severe asthma underwent transition to the adult service between 2014 and 2021. Thirteen patients (25%) were lost to follow-up after an average of 22.4 months of follow-up. Three-quarters (73%) of patients had well controlled asthma with an ACT score ≥20 during transition and the majority were able to maintain good control and respiratory function (>60% FEV₁ >80%) during follow-up in adult pulmonology. Among the patients that answered the questionnaire, 64.8% were satisfied with the transition process.

Conclusion

Asthma control and respiratory function were maintained 6 months and 1 year after transition to the adult centre in the majority of patients. Most patients were satisfied with the transition process, but several improvements can be proposed, including early discussion of the medical plan and the implementation of procedures to reduce loss to follow-up.

Prospective study of disease persistence and lung function trajectories of childhood asthma

BACKGROUND

A proportion of asthmatic children outgrow their disease by adulthood, but there are limited data on predictors for asthma persistence. This prospective study characterized the trajectory of spirometric indices and identified predictors for the persistence of childhood asthma.

METHODS

Chinese asthmatic children aged 6-15 years from pediatric allergy clinic underwent annual visits for ≥5 years and until their adulthood. Pre-bronchodilator spirometry and anti-asthma medications were recorded at baseline and then at least annually. Asthma resolution was defined when patients were free from asthma symptoms and use of anti-asthma drugs for ≥2 years. Logistic regression was used to identify predictors for asthma persistence. Generalized estimating equation was used to analyze longitudinal changes in lung function parameters in relation to asthma persistence.

RESULTS

181 asthmatic children aged [mean (SD)] 10.0 (2.7) years were followed for [mean (SD)] 12.5 (2.8) years. One third of them outgrew asthma during follow-up. Female was 3.36 times more likely to have persistent asthma. Inhaled corticosteroid (ICS) treatment ever and frequent asthma exacerbation (AE) predicted asthma persistence with respective odds ratios of 3.19 (95% confidence interval [CI] 1.44-7.09) and 3.05 (95% CI 1.39-6.68). Persistent asthma was inversely associated with baseline forced expiratory volume in 1-second (FEV₁ %) with an odds ratio of 0.96 (95% CI 0.93-1.00). Throughout follow-up, patients with persistent asthma had generally lower forced expiratory indices than those with asthma resolution. Children with persistent asthma experienced poorer lung function growth.

CONCLUSIONS

Female, ICS ever, and frequent AE predicted persistent asthma. Patients with persistent asthma had lower forced expiratory indices and poorer lung function growth into adulthood.

Pilot study of a brief provider and EMR-based intervention for overweight teens with asthma

INTRODUCTION

Asthma-related morbidity is increased in overweight patients, yet providers are given little guidance on how to discuss weight and asthma management with overweight teens.

OBJECTIVE

We piloted an electronic medical record (EMR)-based tailored discussion guide (TDG) and a brief provider training, to address weight management in overweight teens with asthma. The primary outcome was intervention impact on patient-reported asthma outcomes (e.g., asthma control and morbidity). Secondary outcomes included change in BMI, patient-centeredness, and change in healthy behaviors.

METHODS

Teens aged 13-18 years with persistent asthma and a body mass index ≥ 85th percentile for their age and sex were eligible. Parents of eligible teens were contacted before an upcoming appointment to allow teen enrollment during the clinic visit. Providers reviewed Motivational Interviewing (MI) concepts and were trained in the TDG for support of conversations around weight and asthma management. Measures included asthma outcomes retrieved from the EMR at 6- and 12-month post-baseline, teen impressions of patient-provider communication at 6-week post-enrollment, and teen report of healthy behaviors at 6- and 12-month post-baseline.

RESULTS

Of 44 teens enrolled (77% African-American, 63% female), mean BMI for intervention (n=25) and control groups (n=19) at baseline were similar. Thirty participants (68%) completed a 6-week questionnaire. Compared to controls, at 6 months, intervention teens reported fewer days of limited activity and "uncontrolled asthma," but at 12 months, only restricted activity remained lower, and BMI was not reduced. Intervention teens reported clinic visits that were more patient-centered than controls, including discussion of asthma treatment options with provider, feeling ready to follow an asthma treatment routine, and receiving helpful tips about reaching a healthy weight. The healthy behavior "dinner with family" showed improvement for intervention teens at 6 and 12 months. The feasibility study also revealed a need to improve recruitment strategies and to streamline intervention delivery.

CONCLUSION

Modest improvements in patient-reported asthma outcomes and health behaviors were observed. There was strong evidence that the TDG supports provider discussion of weight and asthma to create a more patient-centered conversation from the perspective of participating teens. Challenges to recruitment and clinic adaptation must be addressed before advancing to a full-scale trial.

TRIAL REGISTRATION

NCT02575326 Teen Asthma Control Encouraging a Healthier Lifestyle, www.cllinicaltrials.gov.

Factors Associated with Persistence of Severe Asthma from Late Adolescence to Early Adulthood

RATIONALE

Asthma severity in children generally starts mild but may progress and stay severe for unknown reasons.

OBJECTIVES

Identify factors in childhood that predict persistence of severe asthma in late adolescence and early adulthood.

METHODS

The Childhood Asthma Management Program is the largest and longest asthma trial in 1041 children aged 5-12 years with mild to moderate asthma. We evaluated 682 participants from the program with analyzable data in late adolescence (age 17-19) and early adulthood (age 21-23).

MEASUREMENTS

Severe asthma was defined using criteria from the American Thoracic Society and the National Asthma Education and Prevention Program to best capture severe asthma. Logistic regression with stepwise elimination was used to analyze clinical features, biomarkers, and lung function predictive of persistence of severe asthma.

MAIN RESULTS

In late adolescence and early adulthood 12% and 19% of the patents had severe asthma, respectively; only 6% were severe at both time periods. For every 5% decrease in post bronchodilator FEV1/FVC in childhood, the odds of persistence of severe asthma increased 2.36-fold (95% CI: 1.70-3.28; p <0.0001), for participants with maternal smoking during pregnancy odds of persistence of severe asthma increased 3.17-fold (95% CI: 1.18-8.53, p=0.02). Reduced growth lung function trajectory was significantly associated with persistence of severe asthma compared to normal growth.

CONCLUSIONS

Lung function and maternal smoking during pregnancy were significant predictors of severe asthma from late adolescence to early adulthood. Interventions to preserve lung function early may prevent disease progression.

Identifying wheezing phenotypes in a pediatric Turkish cohort

OBJECTIVE

Characterization of wheezing phenotypes in children might help to identify the underlying mechanisms through which asthma occurs. In our study, we aimed to describe wheezing phenotypes in Turkish children and to identify risk factors according to phenotypes.

METHODS

651 wheezy children were evaluated and 5 wheezing phenotypes were described according to age of onset, atopy and persistence at 6 years of age and risk factors were identified.

RESULTS

Distribution of wheezing phenotypes was transient early wheeze (TEW)(34.9%) non-atopic wheeze (NAW) (18%), atopic wheeze (AW) (22.3%), intermediate onset wheeze (IOW) (11.1%), late onset wheeze (LOW) (11.7%). LOW, AW, and IOW were associated with, father's, sibling's and family's atopy (p:0.001) whereas LOW and AW were associated with mother's asthma and atopy as well as family's asthma (p < 0.05). Atopic dermatitis and allergic rhinitis were common of patients with LOW, AW, and IOW (p < 0.05). İnfection was the major trigger for TEW and NAW whereas multiple triggers were common of AW, LOW, and IOW. Allergens were mostly associated with AW, IOW and LOW. Aeroallergen-specific IgE positivity was mostly with AW, IOW, and LOW phenotype. Skin prick tests showed multiple allergen sensitivity in IOW, LOW groups and mostly single allergen in AW phenotype. Modified asthma predictive index (mAPI) positivity was high in all groups except TEW and NAW.

CONCLUSIONS

With this study we classified five wheeze phenotypes and found that atopy and family's atopy history, maternal asthma were strongly associated with AW, LOW, and IOW phenotypes which were usually effected by allergens or multiple triggers.

Impact of a diagnostic therapeutic educational pathway program for asthma management in preschool children

Background

Preschool children with clinically-diagnosed asthma have a higher rate of emergency department visits and consume more resources for management than older children. However, no clinical trials have yet been performed measuring the impact of a combined diagnostic, therapeutic and educational pathway regimen for evaluation of wheezing control in children aged less than 6 years.

The purpose of the present study was to assess the impact of a pediatric program developed in Italy, the Diagnostic Therapeutic Educational Pathway (DTEP), for asthma management in children less than 6 years old attending an asthma referral center.

Methods

This is a retrospective population-based cohort study performed in children with asthma aged 0–5 years, attending at “Io e l’Asma center”, Brescia, Italy between September 2007 and December 2014. The incidence rates (IRs) of hospitalization, emergency room visits, use of outpatient services and drug usage for dyspnea, wheezing, or respiratory symptoms were evaluated for time periods prior to and after DTEP intervention.

Results

A total of 741 patients, aged 0–5 years completed the DTEP, including 391 and 350 children aged 0–2 and 3–5 years, respectively. The percentage of children aged 0–2 and 3–5 years showing improved control of wheezing symptoms during the 1st to 3rd visit interval as a result of the DTEP intervention increased from 39.5 to 60.9% and from 25.5 to 75.5%, respectively. During these periods, the IRs showed a significant decrease for all outcomes, from-8.6% to − 80.4%. Although specific IRs for drug prescriptions declined, particularly for LABA plus corticosteroids, antibiotics, and systemic corticosteroids, they increased for SABA, inhaled corticosteroid and leukotriene receptor antagonist usage.

Conclusions

The results suggest that a real-world assessment of the integrated DTEP program for preschool children provides evidence for improved wheezing control and reduction of adverse therapeutic related outcomes.

Enhancing the prediction of childhood asthma remission: Integrating clinical factors with microRNAs

The novel integration of baseline clinical and microRNA variables significantly improves the long-term individualized prediction of childhood asthma remission by early adulthood compared to using clinical variables alone.

Personalized prediction of early childhood asthma persistence: A machine learning approach

Early childhood asthma diagnosis is common; however, many children diagnosed before age 5 experience symptom resolution and it remains difficult to identify individuals whose symptoms will persist. Our objective was to develop machine learning models to identify which individuals diagnosed with asthma before age 5 continue to experience asthma-related visits. We curated a retrospective dataset for 9,934 children derived from electronic health record (EHR) data. We trained five machine learning models to differentiate individuals without subsequent asthma-related visits (transient diagnosis) from those with asthma-related visits between ages 5 and 10 (persistent diagnosis) given clinical information up to age 5 years. Based on average NPV-Specificity area (ANSA), all models performed significantly better than random chance, with XGBoost obtaining the best performance (0.43 mean ANSA). Feature importance analysis indicated age of last asthma diagnosis under 5 years, total number of asthma related visits, self-identified black race, allergic rhinitis, and eczema as important features. Although our models appear to perform well, a lack of prior models utilizing a large number of features to predict individual persistence makes direct comparison infeasible. However, feature importance analysis indicates our models are consistent with prior research indicating diagnosis age and prior health service utilization as important predictors of persistent asthma. We therefore find that machine learning models can predict which individuals will experience persistent asthma with good performance and may be useful to guide clinician and parental decisions regarding asthma counselling in early childhood.

Diagnosis in children with exercise-induced respiratory symptoms: A multi-center study

OBJECTIVE

Exercise-induced respiratory symptoms (EIS) are common in childhood and reflect different diseases that can be difficult to diagnose. In children referred to respiratory outpatient clinics for EIS, we compared the diagnosis proposed by the primary care physician with the final diagnosis from the outpatient clinic and described diagnostic tests and treatments.

DESIGN

An observational study of respiratory outpatients aged 0-16 years nested in the Swiss Paediatric Airway Cohort (SPAC).

PATIENTS

We included children with EIS as the main reason for referral. Information about diagnostic investigations, final diagnosis, and treatment prescribed came from outpatient records. We included 214 children (mean age 12 years, range 2-17, 54% males) referred for EIS.

RESULTS

The final diagnosis was asthma in 115 (54%), extrathoracic dysfunctional breathing (DB) in 35 (16%), thoracic DB in 22 (10%), asthma plus DB in 23 (11%), insufficient fitness in 10 (5%), chronic cough in 6 (3%), and other diagnoses in 3 (1%). Final diagnosis differed from referral diagnosis in 115 (54%, 95%-CI 46%-60%). Spirometry, body plethysmography, and exhaled nitric oxide were performed in almost all, exercise-challenge tests in a third, and laryngoscopy in none. 91% of the children with a final diagnosis of asthma were prescribed inhaled medication and 50% of children with DB were referred to physiotherapy.

CONCLUSIONS

Diagnosis given at the outpatient clinic often differed from the diagnosis proposed by the referring physician. Diagnostic evaluations, management, and follow-up differed between clinics and diagnostic groups highlighting the need for evidence-based diagnostic guidelines and harmonized procedures for children seen for EIS.

ORMDL3/GSDMB genotype as a risk factor for early-onset adult asthma is linked to total serum IgE levels but not to allergic sensitization

BACKGROUND

An orosomucoid-like 3 (ORMDL3)/gasdermin B (GSDMB) gene locus on chromosome 17q is consistently associated with childhood-onset asthma, which is highly atopic. As some evidence suggests the relationship between asthma and allergic sensitization reflects asthma patient susceptibility to augmented IgE responses driven by common environmental allergens rather than an increased asthma risk after allergen exposure, we aimed to determine any relationships between this locus region and childhood-onset adult asthma with regard to serum total IgE levels or allergic sensitization.

METHODS

We conducted a case-control association study using three independent Japanese populations (3869 total adults) and analyzed the ORs for association of rs7216389, an expression quantitative trait locus for ORMDL3/GSDMB, with adult asthma according to onset age. Additionally, associations between the rs7216389 genotype and total serum IgE levels or allergic sensitization was examined.

RESULTS

Rs7216389 was associated with both childhood-onset adult asthma (OR for asthmatic patients afflicted at the age of 10 years or younger = 1.61, p = 0.00021) and asthmatic patients with higher levels of total serum IgE (OR for asthmatic patients with IgE ≥1000IU/mL = 1.55, p = 0.0033). In both healthy controls and in the combined healthy and asthmatic individuals, rs7216389 was correlated with increased total serum IgE levels (p < 0.0005), but not allergic sensitization (p > 0.1).

CONCLUSIONS

ORMDL3/GSDMB is an important susceptibility gene for childhood-onset adult asthma in Japanese populations and this association is linked to elevated total serum IgE levels but not to allergic sensitization.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Transient childhood wheeze is associated with less atopy in adolescence

BACKGROUND

The relationships between childhood wheeze phenotypes and subsequent allergic conditions other than asthma, including hay fever, eczema and sensitization, have not been widely reported. We aimed to investigate this relationship up to late adolescence.

METHODS

Using five childhood wheeze phenotypes defined from 620 children in a high-atopy risk birth cohort (Melbourne Atopy Cohort Study), we investigated their relationships with sensitization, eczema, hay fever and fractional exhaled nitric oxide (FeNO) at ages 12 and/or 18 years using logistic and linear regression models.

RESULTS

'Early Persistent wheeze' was associated with the increased risk of eczema (odds ratio: 3.69; 95% CI: 1.23, 11.12) and sensitization (4.52; 1.50, 13.64) at 12 years. 'Intermediate Onset wheeze' was associated with the increased risk of eczema at 12 years (2.57; 1.11, 5.97), hay fever at 12 (2.87; 1.44, 5.74) and 18 years (2.19; 1.20, 4.02), sensitization at 12 (2.25; 1.17, 4.34) and 18 years (2.46; 1.18, 5.12), and raised FeNO at 18 years. 'Late Onset wheeze' was associated with the increased risk of hay fever at 12 (5.18; 1.11, 24.20) and 18 years (4.20; 1.03, 17.11) and sensitization at 12 years (3.27; 0.81, 13.27). In contrast, 'Early Transient wheeze' was associated with the reduced risk of eczema (0.44; 0.20, 0.96), hay fever (0.57; 0.33, 0.99) and sensitization (0.59; 0.35, 0.99) at 18 years and a lower FeNO compared with 'Never/Infrequent wheezers'.

CONCLUSIONS

Persistent wheeze phenotypes were associated with allergic outcomes up to 18 years with 'Intermediate Onset wheeze' being the most atopic group. In contrast, 'Early Transient wheezers' had less risk of allergic outcomes at 18 years. This protective effect may reassure parents of wheezy infants and young children.

Suboptimal Serum 25-Hydroxy-Vitamin D Is Associated with a History of Recent Disease Exacerbation in Pediatric Patients with Bronchial Asthma or Asthma-Suggestive Recurrent Wheezing

Even though vitamin D is widely acknowledged as having a potential immunomodulatory role in asthma, its exact beneficial mechanisms are yet to be clarified. An optimal serum 25-hydroxy-vitamin D (25-OH-VitD) level in pediatric asthma patients might not rely solely on the effect of dose-dependent vitamin D₃ intake, but might also be influenced by factors related to insufficient asthma control. We aimed to survey the prevalence of serum 25-OH-VitD deficiency and analyze whether suboptimal levels were associated with asthma severity factors. The current cross-sectional study enrolled 131 pediatric asthma or asthma-suggestive recurrent wheezing patients, for whom serum 25-OH-VitD, IgE, and eosinophil count were assessed. The prevalence of suboptimal serum 25-OH-VitD was 58.8%. A suboptimal vitamin D status was associated with asthma exacerbation in the previous month (p = 0.02). Even under seasonal oral vitamin D₃ supplementation, patients with a positive history of asthma attack in the previous four weeks presented significantly lower serum 25-OH-VitD concentrations, compared to their peers with no disease exacerbation. In conclusion, sequential measurements of serum 25-OH-VitD might prove useful for future studies evaluating the dynamic changes in vitamin D₃ status in regard to asthma, especially in symptomatic patients.

The course of asthma: A population-based 10-year study examining asthma remission in children diagnosed with asthma in preschool

BACKGROUND

The natural course of asthma may differ depending on the age of onset.

OBJECTIVE

To investigate predictors of asthma remission with a focus on the age of asthma onset.

METHODS

The study was a retrospective birth cohort of children with asthma in Saskatchewan, Canada. Using the Saskatchewan Ministry of Health databases, we identified children with a diagnosis of asthma in the first 6 years of life and who had at least 10 years of follow-up after diagnosis (n = 22 563). Of these, we included 6393 children either with persistent asthma (≥1 physician visit or hospitalization for asthma [PVHA] during each year of follow-up) and those who had remission (had PVHA in the first year after diagnosis but at some point during the follow-up no longer received PVHA until end of the study). We used survival analysis to examine associations between remission and age of asthma onset.

RESULTS

Of the study participants, 87.2% had early-onset (≤3 years) and 12.8% had late-onset (4-6 years) asthma. Over the 10-years of follow-up, the rate of asthma remission was 37 per 100 person-years. Early-onset asthma (hazard ratio [HR] = 1.10; 95%confidence interval [CI]: 1.01-1.20), being female (HR = 1.12; 95%CI: 1.07-1.18), living in a rural (HR = 1.20; 95%CI: 1.14-1.27) and medium urban (HR = 1.16; 95%CI: 1.08-1.26) location were positively associated with remission while history of atopy decreased likelihood of remission (HR = 0.73; 95%CI: 0.54-0.97).

CONCLUSION

Most children with asthma experienced remission, especially those with the onset of symptoms within the first 3 years of life.

Understanding the dynamics of asthma symptoms between childhood and adolescence using latent transition analysis

OBJECTIVES

Asthma patterns in childhood are important predictors of unwanted outcomes in adolescence. We aimed to define asthma phenotypes in childhood and adolescence and evaluate the transitions between these phenotypes and factors potentially associated with the transitions.

METHODS

Baseline (1445 children), first round (1363 children/early adolescents) and second round (1206 adolescents) data from the SCAALA Project in Salvador, Brazil, were used. Phenotypes were defined by latent class analysis at three time points. Transitions between phenotypes were described and the effects of factors associated with transition probabilities estimated using latent transition analysis.

RESULTS

The "asymptomatic" and "symptomatic" phenotypes were identified. Approximately 5-6% of asymptomatic children in childhood/later childhood and early adolescence became symptomatic later in time. Maternal common mental disorders were identified as important risk factor for unhealthy states.

CONCLUSIONS

Asthma manifestations are characterized by frequent movements, especially between childhood and adolescence. Our study, by simultaneously defining disease subtypes, and examining the transitions and their potential predictors, highlights the importance of longitudinal studies to advance the understanding of the effects of social, environmental and biological mechanisms underlying asthma trajectories over time.

DNA methylation down-regulates integrin β4 expression in asthmatic airway epithelial cells

BACKGROUND

Integrin β4 (ITGB4) is a hemi-desmosome protein which is downregulated in the airway epithelial cells of asthma patients. The proximal promoters and exons of ITGB4 contain CpG islands or multiple CpG sites both in human and mice, which indicated the possible methylation regulation of ITGB4 in airway epithelial cells.

OBJECTIVE

We sought to unveil that DNA methylation regulates the decreased ITGB4 during the pathogenesis of asthma.

METHODS

Mice were exposed to house dust mite (HDM) extracts to construct an asthma model. 5-Aza-2'-deoxycytidine (5-AZA) or dexamethasone (DEX) were added in the last two weeks. Besides, the primary human bronchial epithelial (HBE) cells were incubated for the detection of ITGB4 expression and methylation status after HDM stress. Furthermore, DNA methylation of ITGB4 in peripheral blood was measured in asthma patients. Logistic regression was employed to evaluate the association between methylation sites and asthma patients' ages in the control of potential confounders. Moreover, the correlations between differentially methylated sites (DMSs) and clinical parameters in asthma patients were assessed. Finally, the ability of candidate DMSs to predict asthma was evaluated by receiver operating characteristic (ROC) analysis and principal component analysis (PCA).

RESULTS

We found that in HDM-stressed asthma model, DNA methylation regulated the reduced ITGB4 expression in airway epithelial cells. Moreover, alteration in the specific CpG sites (chr17:73717720 and chr17:73717636) of ITGB4 may regulate ITGB4 expression and further may be associated with the clinically phenotypic of asthma. The specific DMSs of ITGB4 in peripheral blood can distinguish asthma patients from healthy controls (HCs) effectively.

CONCLUSIONS AND CLINICAL RELEVANCE

This study confirmed that DNA methylation regulates the decreased expression of ITGB4 in the airway epithelial cells of asthma patients. These results supply some useful insights to the mechanism of the decreased ITGB4 in asthmatic airway epithelial and provide possible targets for early prediction and screening of asthma.

Asthma prevalence and risk factors in school children: The RESPIR longitudinal study

OBJECTIVES

To analyze the incidence of wheezing in the first six years of life; the prevalence of asthma at six years of age; and the associated risk factors, in a population from Valencia, Spain.

METHODS

A prospective longitudinal study was made of a cohort of 636 newborn infants, with follow-up of the clinical records and the completion of questionnaires up to the age of six years.

RESULTS

The prevalence of asthma at six years of age was 12.8%. Up until that age, 63% of the study population had experienced at least one episode of wheezing, and 35% had suffered recurrent wheezing (three or more episodes). Admission due to wheezing was associated to school asthma. The following risk factors were identified: atopic dermatitis (OR: 2.1; 95%CI: 1.2-3.5), the presence of at least one episode of wheezing in the first year (OR: 1.8; 95%CI: 1.1-2.9), prematurity (OR: 2.5; 95%CI: 1.2-5.1), and a family history of asthma (OR: 2.2; 95%CI: 1.2-4.1).

CONCLUSIONS

The prevalence of asthma at six years of age in our population is similar to that described in other longitudinal studies. An important increase is observed in the cumulative incidence of wheezing and of recurrent wheezing up to three years of age, followed by stabilization. The most relevant risk factors for developing asthma at six years were atopic dermatitis, wheezing during the first year, prematurity, and a family history of asthma. Full-term pregnancy and the minimization of respiratory infections at an early age could reduce the prevalence of asthma at six years of age in our population.

Persistent Asthma from Childhood to Adulthood Presents a Distinct Phenotype of Adult Asthma

BACKGROUND

In approximately 30% of children with asthma, the condition persists into adulthood. The longer duration of asthma in these patients is a risk factor for poor asthma control. However, the characteristics of adult patients with asthma that has persisted since childhood are not well documented.

OBJECTIVE

We sought to compare the clinical characteristics among patients with adult-onset asthma, patients who outgrew childhood asthma but relapsed, and patients with persistent asthma since childhood.

METHODS

We conducted a cross-sectional study of adult patients with asthma who visited our hospital. We classified them into 3 groups: those with adult-onset asthma (adult-onset), those who had remitted childhood asthma that relapsed (relapsed), and those who had asthma that had persisted since childhood (persistent). The clinical characteristics of these groups were compared.

RESULTS

A total of 1443 patients were enrolled. The persistent group was younger and included fewer patients with a smoking history. There were statistically significant differences among the 3 groups in the percentages of patients with a family history of asthma and comorbidities of allergic rhinitis and atopic dermatitis. The proportion of patients with severe asthma differed among the 3 groups (31% in the adult-onset group, 34% in the relapsed group, and 40% in the persistent group; P = .015). The values of forced expiratory flow at 75% of vital capacity were lower in the persistent group than the relapsed or adult-onset group. A multivariable logistic regression analysis (dependent variable: severe asthma) in each group revealed that the factors associated with severe asthma differed among the adult-onset, relapsed, and persistent groups. When we established an overall model that included interaction terms of cohort-by-other factors, there was a trend that comorbidity of allergic rhinitis affected the severity of asthma differently in the relapsed group compared with the other groups.

CONCLUSION

The clinical phenotype of asthma that persists from childhood to adulthood seems to be a distinct phenotype of adult asthma.

Personal and early life factors associated with new-onset asthma, remission, and persistence of asthma in a 2-year follow-up of schoolchildren

OBJECTIVE

The natural course of childhood asthma, after its onset, is characterized by periods of persistence, relapse and remission. To investigate personal and early life factors associated with new-onset asthma, persistence and remission among children.

METHODS

The study was conducted in the province of Saskatchewan, Canada. Children in grades Kindergarten to Grade 8 (ages 5-14 years) participated in a cross-sectional study in 2013. In 2015, we approached those who gave consent in 2013 to be re-contacted, creating a prospective cohort. Data were collected using questionnaires in both years. Participants in 2013 who also had data in 2015 (25%: n = 324/1,348) had their asthma status reclassified and longitudinal descriptors were applied: "no asthma", "new-onset asthma", "persistent" or "remission". Personal and early life factors associations with asthma outcomes in 2015 were evaluated.

RESULTS

Among those without asthma in 2013 (n = 245), the incidence of new-onset asthma in 2015 was 7.2%. Among those with asthma in 2013 (n = 79), 47.1% had remission and 52.9% had persistent asthma in 2015. Parental history of asthma (adjusted odds ratio (aOR): 4.99; 95% confidence interval (CI): 1.88-28.27), early life respiratory infection (aOR: 1.92; 95%CI: 1.47-7.88), early life allergy [aOR: 6.39; 95%CI: 1.34-30.58) and early life infection (aOR: 4.99; 95%CI: 1.19-20.93) were associated with new onset asthma. Similarly, while parental history of asthma (aOR: 1.13; 95%CI: 0.29-4.34), early life respiratory infection (aOR: 2.71; 95%CI: 0.70-10.45), and early life ear infection (aOR: 1.34; 95%CI: 0.36-5.05) were also positively association with persistent asthma, the associations were not statistically significant.

CONCLUSION

Parental history of asthma, early life respiratory infection and allergy might not only influence the onset of childhood asthma but also be associated with asthma persistence.

Do clinical investigations predict long-term wheeze? A follow-up of pediatric respiratory outpatients

INTRODUCTION

The contribution of clinical investigations to prediction of long-term outcomes of children investigated for asthma is unclear.

AIM

We performed a broad range of clinical tests and investigated whether they helped to predict long-term wheeze among children referred for evaluation of possible asthma.

METHODS

We studied children aged 6 to 16 years referred to two Swiss pulmonary outpatient clinics with a history of wheeze, dyspnea, or cough in 2007. The initial assessment included spirometry, fractional exhaled nitric oxide, skin prick tests, and bronchial provocation tests by exercise, methacholine, and mannitol. Respiratory symptoms were assessed with questionnaires at baseline and at follow-up 7 years later. Associations between baseline factors and wheeze at follow-up were investigated by logistic regression.

RESULTS

At baseline, 111 children were examined in 2007. After 7 years, 85 (77%) completed the follow-up questionnaire, among whom 61 (72%) had wheeze at baseline, while at follow-up 39 (46%) reported wheeze. Adjusting for age and sex, the following characteristics predicted wheeze at adolescence: wheeze triggered by pets (odds ratio, 4.2; 95% CI, 1.2-14.8), pollen (2.8, 1.1-7.0), and exercise (3.1, 1.2-8.0). Of the clinical tests, only a positive exercise test (3.2, 1.1-9.7) predicted wheeze at adolescence.

CONCLUSION

Reported exercise-induced wheeze and wheeze triggered by pets or pollen were important predictors of wheeze persistence into adolescence. None of the clinical tests predicted wheeze more strongly than reported symptoms. Clinical tests might be important for asthma diagnosis but medical history is more helpful in predicting prognosis in children referred for asthma.

Lost in the transition from pediatric to adult healthcare? Experiences of young adults with severe asthma

Objective: Asthma is a multifaceted disease, and severe asthma is likely to be persistent. Patients with severe asthma have the greatest burden and require more healthcare resources than those with mild-to-moderate asthma. The majority with asthma can be managed in primary care, while some patients with severe asthma warrant referral for expert advice regarding management. In adolescence, this involves a transition from pediatric to adult healthcare. This study aimed to explore how young adults with severe asthma experienced the transition process.Methods: Young adults with severe asthma were recruited from an ongoing Swedish population-based cohort. Qualitative data were obtained through individual interviews (n = 16, mean age 23.4 years), and the transcribed data were analyzed with systematic text condensation.Results: Four categories emerged based on the young adults' experiences: "I have to take responsibility", "A need of being involved", "Feeling left out of the system", and "Lack of engagement". The young adults felt they had to take more responsibility, did not know where to turn, and experienced fewer follow-ups in adult healthcare. Further, they wanted healthcare providers to involve them in self-management during adolescence, and in general, they felt that their asthma received insufficient support from healthcare providers.Conclusions: Based on how the young adults with severe asthma experienced the transition from pediatric to adult healthcare, it is suggested that healthcare providers together with each patient prepare, plan, and communicate in the transition process for continued care in line with transition guidelines.

Risk factors and prognosis of recurrent wheezing in Chinese young children: a prospective cohort study

Background

Nearly all the investigations into the risk factors for wheezing and asthma were conducted in developed countries with a high prevalence rate of asthma and allergy, but the studies in developing countries are limited. In this study, we aimed to investigate the risk factors for different wheezing phenotypes in Chinese young children and to explore the prognosis of recurrent wheezing.

Methods

This cohort study contained the recruitment stage and the follow-up stage conducted by phone questionnaire survey. According to the information collected at the follow-up for wheezing episodes and remission age, our cohort was divided into transient wheezing, persistent wheezing and late-onset wheezing. The wheezing symptoms and potential risk factors were compared between these three wheezing groups.

Results

From the initial 109 participants, 78.0% completed the follow-up survey. The frequency of current wheezing at followup was significantly reduced in all three groups compared to the recruitment stage (p < 0.01). We observe a trend that the rhinovirus (RV) and respiratory syncytial virus (RSV) infection rates were higher in the persistent wheezing group, and the overall infection rates appear to be the lowest in late-onset wheezing group at recruitment. At follow-up stage, the rates of rhinitis ever and current rhinitis were both higher in the persistent wheezing (63.0%, 50.0%) and late-onset wheezing groups (88.2%, 58.8%), compared to the transient wheezing group (14.3%, 14.3%). The incidence of current wheezing episodes increased cumulatively if the participant had concomitant risk factors of rhinitis ever, aeroallergens sensitization at recruitment, either alone or together with previous RV infection at the time of recruitment.

Conclusion

While the incidence of wheezing declined overall with age, but in addition to transient wheezers, additional subsets of children manifest persistent wheeze or late onset wheeze, and moreover the risk factors for wheezing display phenotypic variability between these subgroups. Rhinitis ever and aeroallergens sensitization, either alone or together with previous RV infection, were the most significant predictors for persistent wheezing in children in an eastern environment, such as in China.

Changes in asthma severity in the first year of school and difficulty learning to read

Objective: Asthma is a risk factor for poor early reading in children, for reasons that are unclear. This analysis examines the relationship between changes in asthma severity during the first year of school and being in the lowest quartile of reading achievement after 1 year of school.Methods: We used previously unreported data from our cohort study. Parent interviews and teacher questionnaires enquired about asthma and covariates of achievement at school entry (T1) and 12 months later (T2). Asthma severity scores at T1 and T2 showed that in 27 of 51 children with asthma, symptoms improved over the year, whereas in 24, symptoms persisted or worsened. Word and story reading were assessed at T1 and T2. We compared reading achievement at both timepoints between children with asthma and children who had no reported respiratory symptoms between birth and T2 (controls, N = 74), and between those with persistent versus improved symptoms.Results: More children with asthma than controls were in the lowest quartiles for reading. Further, significantly more children in the persistent group compared to the improved group were in the lowest quartiles for word reading (58 versus 30%, respectively) and story reading (54 versus 26%, respectively). School absences, increased behavior problems, stressful life events or parental mental health were not associated with the differences in either comparison. Logistic regression modeling identified persistent asthma as the most important variable associated with being in the lowest quartile of reading after 1 year in school.Conclusions: Active asthma symptoms during early school may influence early reading achievement.

Causes of variability in latent phenotypes of childhood wheeze

BACKGROUND

Latent class analysis (LCA) has been used extensively to identify (latent) phenotypes of childhood wheezing. However, the number and trajectory of discovered phenotypes differed substantially between studies.

OBJECTIVE

We sought to investigate sources of variability affecting the classification of phenotypes, identify key time points for data collection to understand wheeze heterogeneity, and ascertain the association of childhood wheeze phenotypes with asthma and lung function in adulthood.

METHODS

We used LCA to derive wheeze phenotypes among 3167 participants in the ALSPAC cohort who had complete information on current wheeze recorded at 14 time points from birth to age 16½ years. We examined the effects of sample size and data collection age and intervals on the results and identified time points. We examined the associations of derived phenotypes with asthma and lung function at age 23 to 24 years.

RESULTS

A relatively large sample size (>2000) underestimated the number of phenotypes under some conditions (eg, number of time points <11). Increasing the number of data points resulted in an increase in the optimal number of phenotypes, but an identical number of randomly selected follow-up points led to different solutions. A variable selection algorithm identified 8 informative time points (months 18, 42, 57, 81, 91, 140, 157, and 166). The proportion of asthmatic patients at age 23 to 24 years differed between phenotypes, whereas lung function was lower among persistent wheezers.

CONCLUSIONS

Sample size, frequency, and timing of data collection have a major influence on the number and type of wheeze phenotypes identified by using LCA in longitudinal data.

Remission of persistent childhood asthma: Early predictors of adult outcomes

BACKGROUND

Few data exist on the predictors of asthma remission by early adulthood in North America.

OBJECTIVE

The predictors of adult asthma remission were determined in a multiethnic population of patients with mild-to-moderate persistent childhood asthma.

METHODS

Asthma remission in early adulthood was measured by using 2 definitions: a clinical and a strict definition. Both included normal lung function and the absence of symptoms, exacerbations, and medication use. The strict definition also included normal airways responsiveness. Predictors were identified from 23 baseline measures by using multivariate logistic regression. The probability of remission was modeled by using decision tree analysis.

RESULTS

In 879 subjects the mean ± SD baseline age was 8.8 ± 2.1 years, 59.4% were male, and 68.7% were white. By adulthood, 229 (26.0%) of 879 participants were in clinical remission, and 111 (15.0%) of 741 participants were in strict remission. The degree of FEV1/forced vital capacity (FVC) ratio impairment was the largest predictor of asthma remission. More than half of boys and two thirds of girls with baseline FEV1/FVC ratios of 90% or greater were in remission at adulthood. Decreased airways responsiveness was also a predictor for both remission definitions (clinical remission odds ratio, 1.23 [95% CI, 1.09-1.39]; strict remission odds ratio, 1.52 [95% CI, 1.26-1.84]). The combination of normal FEV1/FVC ratio, airways responsiveness, and serum eosinophil count at baseline yielded greater than 80% probability of remission by adulthood.

CONCLUSION

A considerable minority of patients with persistent childhood asthma will have disease remission by adulthood. Clinical prognostic indicators of asthma remission, including baseline lung function, can be seen from an early age.

Long-term impacts of prenatal and infant exposure to fine particulate matter on wheezing and asthma: A systematic review and meta-analysis

This systematic review aimed to summarize epidemiologic evidence regarding long-term effects of prenatal and infant particulate matter with an aerodynamic diameter less than 2.5 µm (PM_2.5) exposure on wheezing and asthma.

Methods

Epidemiologic data investigating the associations between ambient PM_2.5 exposures during prenatal or the first 2 years of life and wheezing or asthma throughout life were extracted from five databases. All included studies were assessed according to the Critical Appraisal Skills Programme checklists. We performed meta-analyses if ≥2 studies estimated the effects of continuous PM_2.5.

Results

Nine of 18 eligible studies were suitable for meta-analyses. For prenatal PM_2.5 exposure and asthma by 10 years of age (n = 4), the overall risk estimate per 10-unit increase (95% confidence interval) was 1.12 (1.00, 1.26). Although meta-analysis of prenatal exposure and wheezing by 4 years of age (n = 5) was not possible due to inconsistent exposure and outcome assessments, four studies found strong positive associations with wheeze by 2 years of age. The overall risk of developing asthma (n = 5) and wheezing (n = 3) by 8 years of age for infant PM_2.5 exposure was 1.14 (0.96, 1.35) and 1.49 (0.99, 2.26), respectively. One large high-quality study reporting risk differences not suitable for meta-analysis demonstrated significant associations between prenatal or infant PM_2.5 exposure and childhood asthma. High heterogeneity was present among studies of prenatal exposures and asthma, whereas studies of other associations showed low heterogeneity. There was insufficient evidence about susceptible subgroups.

Conclusions

The limited and inconsistent evidence is suggestive of an association between early life PM_2.5 exposure and wheezing/asthma. Large standardized studies are needed to explore the associations and identify vulnerable populations.

Development of an asthma risk factors scale (ARFS) for risk assessment asthma screening in children

BACKGROUND

The study objective was to create asthma risk factors scale (ARFS) score that would be correlated with the increased risk of asthma in Lebanese children. This scale would eventually be used both to identify children at risk and assess early diagnosis of asthma.

METHODS

A case-control study (study 1) of 1276 children (976 controls and 300 cases) and a cross-sectional study (study 2) of 1000 children were conducted using a parental questionnaire. Children aged between 3 and 16 years were screened for possible enrollment. The ARFS was created by combining the following risk factors: child's exposure to pesticides, detergent mixing, alcohol, smoking and drug intake during pregnancy and breastfeeding, the actual paternal and maternal smoking status and history of asthma, and the types of food the child consumes.

RESULTS

There was a significant increase in the risk assessment screening for asthma per 15 points increments of ARFS (p < 0.001 for trend). The score category 0-14.99 best-represented control individuals (88.8% controls), while a score higher than 45 represented asthmatic children best (98.4% asthmatics). The positive predictive value (disease positive/all positive by scale) came out as 94.02%, whereas the negative predictive value (disease negative/all negative by scale) was found to be 90.47%. These results were confirmed in the second study sample.

CONCLUSION

The ARFS is a simple and easy-to-use tool, composed of 15 questions, for the clinician risk assessment of asthma in children, taking into account the environmental exposure, parental history of asthma and dietary habits of the child. Its value for asthma diagnosis remains to be confirmed in future prospective studies, especially in children with chronic respiratory symptoms.

Airway hyperresponsiveness in young children with respiratory symptoms: A five-year follow-up

BACKGROUND

Recurrent wheezing in early life is transient in most children. The significance of airway hyperresponsiveness (AHR) in persistence of respiratory symptoms from infancy to early childhood is controversial.

OBJECTIVE

We evaluated whether AHR in wheezy infants predicts doctor-diagnosed asthma (DDA) or AHR at the age of 6 years.

METHODS

Sixty-one wheezy infants (age 6-24 months) were followed up to the median age of 6 years. Lung function and AHR with methacholine challenge test were assessed at infancy and 6 years. The exercise challenge test was performed at the age of 6 years. Atopy was assessed with skin prick tests.

RESULTS

At 6 years, 21 (34%) of the children had DDA. Children with DDA had higher logarithmic transformed dose-response slope (LOGDRS) to methacholine in infancy than children without DDA (0.047 vs 0.025; P = .033). Furthermore, AHR to methacholine in infancy and at 6 years were associated with each other (r = 0.324, P = .011). Children with exercise-induced bronchoconstriction (EIB) at 6 years were more reactive to methacholine in infancy than those without EIB (P = .019).

CONCLUSION

Increased AHR in symptomatic infants was associated with increased AHR, DDA, and EIB at median the age of 6 years, suggesting early establishment of AHR.

Can early intervention in pediatric asthma improve long-term outcomes? A question that needs an answer

OBJECTIVE

Although many children with asthma do not experience persistence into adulthood, recent studies have suggested that poorly controlled asthma in childhood may be associated with significant airflow obstruction in adulthood. However, data regarding disease progression are lacking, and clinicians are not yet able to predict the course of a child's asthma. The goal of this article was to assess the current understanding of childhood asthma treatment and progression and to highlight gaps in information that remain.

DATA SOURCES

Nonsystematic PubMed literature search and authors' expertise.

STUDY SELECTION

Articles were selected at the authors' discretion based on areas of interest in childhood asthma treatment and progression into adulthood.

RESULTS

Uncontrolled asthma in early childhood can potentially have lasting effects on lung development, but it is unclear whether traditional interventions in very young children preserve lung function. Although not all children respond to standard interventions, certain asthma phenotypes have been identified that can help to understand which children may respond to a particular treatment.

CONCLUSION

Clinicians should monitor children's asthma control and pulmonary function over time to assess the long-term impact of an intervention and to minimize the effect of uncontrolled asthma, especially exacerbations, on lung development. New biologic therapies have shown promise in treating adults with severe, uncontrolled asthma, and some of these therapies are approved in the United States for children as young as age 6. However, knowledge gaps regarding the efficacy and safety of these treatments in younger children hamper our understanding of their effect on long-term outcomes.

Question 3: Can we diagnose asthma in children under the age of 5 years?

The diagnosis of asthma in children under five years has been controversial due to changing concepts of what true asthma is in this age group. Previous diagnostic algorithms that used clinical indices to predict the persistence of asthma symptoms or phenotypes based on asthma triggers do not predict which children will benefit from asthma medication. A pragmatic approach to asthma diagnosis in this age group is based on identifying signs and symptoms of reversible airflow obstruction and documenting their response to asthma medication. Hopefully, this approach will provide clearer guidance to clinicians and improve asthma morbidity in these young children.

New insights to improve treatment adherence in asthma and COPD

Chronic respiratory diseases such as asthma and COPD are typically managed by daily inhaled medication. However, the efficacy of an inhaled medication depends upon a patient's adherence to therapy, which refers to whether the medication is actually taken as prescribed. In patients with these diseases, higher adherence has been associated with better health outcomes, such as improved disease control and a reduction in severe and potentially costly exacerbations. Adherence is a multifaceted concept that includes medication-related, intentional, and unintentional reasons that patients may or may not take their medication as directed. The purpose of this integrative review is to present the individual patient factors that contribute to suboptimal adherence to inhaled therapies and the associated effects on health outcomes, while also highlighting evidence-based strategies for health care providers to improve adherence to such therapies in patients with asthma or COPD. Working closely with patients to establish a model of shared decision-making, which takes patient beliefs and preferences into account when choosing treatment options, has the potential to improve adherence and overall patient outcomes in the management of asthma and COPD.

Practical and Conceptual Considerations for the Primary Prevention of Asthma

Asthma is among the most common chronic diseases worldwide and is a significant contributor to the global health burden, highlighting the urgent need for primary prevention. This article outlines several practical and conceptual challenges that accompany primary prevention efforts. It advocates for improved predictive modeling to identify those at high-risk of developing asthma using automated algorithms within electronic medical records systems and explanatory modeling to refine understanding of causal pathways. Understanding the many issues that are likely to affect the success of primary prevention efforts helps the community of individuals invested in asthma prevention organize efforts and maximize their impact.