Wheezing in childhood: incidence, longitudinal patterns and factors predicting persistence

Impaired interferon response in plasmacytoid dendritic cells from children with persistent wheeze

BACKGROUND

Impaired interferon response and allergic sensitization may contribute to virus-induced wheeze and asthma development in young children. Plasmacytoid dendritic cells (pDCs) play a key role in antiviral immunity as critical producers of type I interferons. pDCs also express the high-affinity IgE receptor through which type I interferon production may be negatively regulated. Whether antiviral function of pDCs is associated with recurrent episodes of wheeze in young children is not well understood.

OBJECTIVE

We sought to evaluate the phenotype and function of circulating pDCs in children with a longitudinally defined wheezing phenotype.

METHODS

We performed multiparameter flow cytometry on PBMCs from 38 children presenting to the emergency department with an acute episode of respiratory wheeze and 19 controls. RNA sequencing on isolated pDCs from the same individuals was also performed. For each subject, their longitudinal exacerbation phenotype was determined using the Western Australia public hospital database.

RESULTS

We observed a significant depletion of circulating pDCs in young children with a persistent phenotype of wheeze. The same individuals also displayed upregulation of the FcεRI on their pDCs. Based on transcriptomic analysis, pDCs from these individuals did not mount a robust systemic antiviral response as observed in children who displayed a nonrecurrent wheezing phenotype.

CONCLUSIONS

Our data suggest that circulating pDC phenotype and function are altered in young children with a persistent longitudinal exacerbation phenotype. Expression of high-affinity IgE receptor is increased and their function as major interferon producers is impaired during acute exacerbations of wheeze.

Component-resolved diagnosis in childhood and prediction of asthma in early adolescence: A birth cohort study

INTRODUCTION

Component-resolved diagnosis (CRD) has been decisive in exploring the mechanisms of IgE sensitization, but the predictive ability to detect asthma has not been addressed. We aim to develop and evaluate the performance of a personalized predictive algorithm for asthma that integrates information on allergic sensitization using CRD.

METHODS

One thousand one hundred one twenty-five children from the Generation XXI birth cohort were randomly selected to perform a screening test for allergic sensitization and a subsample was characterized using CRD against 112 allergen components. Allergen components were analyzed using volcano plots and partial least squares (PLS) analysis. Logistic regression was performed to assess the associations between the obtained latent components (LC) and allergic outcomes (asthma, rhinitis, eczema) including other potential predictors used in previous asthma risk scores. The accuracy of the model in predicting asthma was assessed using Receiver Operating Characteristic (ROC) curve statistics.

RESULTS

In the PLS, the first LC was positively associated with asthma, rhinitis, and eczema. This LC was mainly driven by positive weights for Der p 1/2/23, Der f 1/2, and Fel d 1. The main components in the second LC were pollen and food allergens. History of early wheezing and parental allergy were included in the predictive model and the area under the curve improved to 0.82.

CONCLUSIONS

This is the first approach to improve the clinical applicability of CRD by combining CRD and clinical data to predict asthma at 13 years. Sensitization to distinct allergen molecules seems relevant to improve the accuracy of asthma prediction models.

Burden and unmet need for specialist care in poorly controlled and severe childhood asthma in a Danish nationwide cohort

BACKGROUND

Asthma is a common disease in childhood and adolescence with lifelong consequences particularly among those at risk of severe disease, poor control and/or frequent exacerbations. Specialist care is recommended for at-risk children and adolescents, yet access to specialist management in free-to-access healthcare settings remains poorly understood.

METHODS

A Danish nationwide cohort of children and adolescents aged 2-17 years with persistent asthma, defined as repeated redemption of inhaled corticosteroids (ICS) during 2015, were followed for two years, to identify at-risk children and adolescents comprising those with severe asthma (classified according to GINA 2020 guidelines), poor control (defined as use of 400/600 (ages 2-11/12 +) annual doses of short-acting bronchodilators), or frequent exacerbations (defined as use of oral steroids or hospitalization), and access to specialist care. The population is chosen due to detailed medical records in the setting of universal health care.

RESULTS

The cohort comprised of 29,851 children and adolescents (59% boys), with a median age of 9 years. While 17% of children were on high dose ICS, 22% were on daily ICS below GINA low dose cut-off. Prevalence of severe asthma (3.0-6.5%) was lower than poor asthma control (6.4-25%); both declined from childhood to adolescence. Exacerbations occurred in 7.1-9.0% of children, with median number of exacerbations being 1 (IQR 1-1). Despite being classified as having mild-to-moderate asthma, 15% had poor asthma control and 3.8% experienced exacerbation(s), respectively. While 61% of children with severe asthma and 58% with exacerbation-prone disease were in specialist care, only 24% with uncontrolled disease were receiving specialist care. Of children and adolescents using high-dose ICS, 71% were managed in primary care, while the use of additional controllers was more common in specialist care.

CONCLUSIONS

Throughout childhood and adolescence, there was a high prevalence of severe asthma and poor control, although their prevalence declined with age. We demonstrate a large unmet need for specialist care among children with at-risk asthma, particularly among those with poorly controlled asthma, even in a system with free-to-access, tax-funded healthcare.

Clinical form of asthma and vaccine immunity in preschoolers

Introduction

Asthma is the most common chronic disease in children. Its exacerbation results from allergic and infectious diseases.

Aim

To assess the influence of a clinical form of asthma on preschoolers’ vaccine immunity following 3 years after the completion of the mandatory vaccination programme.

Material and methods

The study encompassed 172 preschool children with asthma being newly diagnosed, including 140 patients with mild asthma and 32 with moderate asthma, whose vaccine immunity (level of IgG-specific antibodies) was assessed after the mandatory early vaccines had been administered in the early childhood. Monovalent vaccines (HBV + IPV + Hib) along with a three-component combined vaccine (DTwP) and MMR were given to 86 children while a six-component combined vaccine (DTaP + IPV + Hib + HBV) along with a three-component MMR vaccine were administered to the remaining 86 children. The immunity class for particular vaccinations was assessed according to the manufacturers’ instructions.

Results

Children suffering from mild asthma had considerably more frequently vaccinations administered on time (p < 0.001) and the type of vaccines (monovalent or highly-combined) administered did not have a significant influence on the clinical form of asthma in the children examined (p = 0.6951). Apart from the vaccines against hepatitis B and rubella where considerably more frequently a high level of antibodies occurred in children with mild asthma, the antibody levels to other vaccines, namely diphtheria, tetanus, pertussis, Hib and mumps, were not associated with the severity of asthma.

Conclusions

Moderate asthma may have a negative impact on remote vaccine immunity to HBV and rubella.

Does fetal leptin and adiponectin influence children's lung function and risk of wheeze?

Adipocytokines, which are secreted during fetal development by both mothers and fetuses, may influence fetal lung development, but little human data are available. We used data from the HOME Study to investigate the associations of cord blood adipocytokine concentrations with children's lung forced expiratory volume (FEV1; N = 160) and their risk of wheeze (N = 281). We measured umbilical cord serum adipocytokine concentrations using enzyme-linked immunosorbent assays and FEV1 using a portable spirometer at ages 4 and 5 to calculate the percent predicted FEV1 (%FEV1). Parents completed standardized questionnaires of their child's wheeze symptoms every 6 months from birth to age 5, then again at ages 6 and 8. We used multivariable linear mixed models and modified Poisson regression with generalized estimating equations to estimate associations of adipocytokine concentrations (log2-transformed) with children's %FEV1 and the risk of wheeze, respectively, adjusting for sociodemographic, perinatal, and child factors. Cord serum leptin was not associated with children's %FEV1. Higher cord serum adiponectin concentrations were associated with higher %FEV1 in girls (β = 3.1, 95% confidence interval [CI]: 0.6, 5.6), but not in boys (β = -1.3, 95% CI: -5.9, 3.3) (sex × adiponectin p-value = 0.05). Higher leptin was associated with lower risk of wheeze in girls (RR = 0.74, 95% CI: 0.66, 0.84), but not boys (RR = 0.87, 95% CI: 0.69, 1.11) (sex × leptin p-value = 0.01). In contrast, higher adiponectin concentrations were associated with lower risk of wheeze (RR = 0.84, 95% CI: 0.73, 0.96) in both boys and girls. These data suggest that fetal adipocytokines may impact lung development and function in early childhood. Future studies are needed to confirm these findings and explore the mechanisms underlying these associations.

Chitinase-Induced Airway Hyperreactivity and Inflammation in a Mouse Model of Nonallergic Asthma

INTRODUCTION

Environmental exposure to mites and fungi has been proposed to critically contribute to the development of IgE-mediated asthma. A common denominator of such organisms is chitin. Human chitinases have been reported to be upregulated by interleukin-13 secreted in the context of Th2-type immune responses and to induce asthma. We assessed whether chitin-containing components induced chitinases in an innate immune-dependent way and whether this results in bronchial hyperresponsiveness.

MATERIALS AND METHODS

Monocyte/macrophage cell lines were stimulated with chitin-containing or bacterial components in vitro. Chitinase activity in the supernatant and the expression of the chitotriosidase gene were measured by enzyme assay and quantitative PCR, respectively. Non-sensitized mice were stimulated with chitin-containing components intranasally, and a chitinase inhibitor was administered intraperitoneally. As markers for inflammation leukocytes were counted in the bronchoalveolar lavage (BAL) fluid, and airway hyperresponsiveness was assessed via methacholine challenge.

RESULTS

We found both whole chitin-containing dust mites as well as the fungal cell wall component zymosan A but not endotoxin-induced chitinase activity and chitotriosidase gene expression in vitro. The intranasal application of zymosan A into mice led to the induction of chitinase activity in the BAL fluid and to bronchial hyperresponsiveness, which could be reduced by applying the chitinase inhibitor allosamidin.

DISCUSSION

We propose that environmental exposure to mites and fungi leads to the induction of chitinase, which in turn favors the development of bronchial hyperreactivity in an IgE-independent manner.

Preventing asthma in high risk kids (PARK) with omalizumab: Design, rationale, methods, lessons learned and adaptation

Asthma remains one of the most important challenges to pediatric public health in the US. A large majority of children with persistent and chronic asthma demonstrate aeroallergen sensitization, which remains a pivotal risk factor associated with the development of persistent, progressive asthma throughout life. In individuals with a tendency toward Type 2 inflammation, sensitization and exposure to high concentrations of offending allergens is associated with increased risk for development of, and impairment from, asthma. The cascade of biological responses to allergens is primarily mediated through IgE antibodies and their production is further stimulated by IgE responses to antigen exposure. In addition, circulating IgE impairs innate anti-viral immune responses. The latter effect could magnify the effects of another early life exposure associated with increased risk of the development of asthma - viral infections. Omalizumab binds to circulating IgE and thus ablates antigen signaling through IgE-related mechanisms. Further, it has been shown restore IFN-α response to rhinovirus and to reduce asthma exacerbations during the viral season. We therefore hypothesized that early blockade of IgE and IgE mediated responses with omalizumab would prevent the development and reduce the severity of asthma in those at high risk for developing asthma. Herein, we describe a double-blind, placebo-controlled trial of omalizumab in 2-3 year old children at high risk for development of asthma to prevent the development and reduce the severity of asthma. We describe the rationale, methods, and lessons learned in implementing this potentially transformative trial aimed at prevention of asthma.

Recurrent wheezing after bronchiolitis caused by respiratory syncytial virus in children younger than 3 years: A 1-year follow-up study

We analysis the frequency and risk factors of wheezing in infants. We chose children with initial wheezing before 3 years of age who were hospitalized for medical treatment. Wheezing frequency was determined by follow-up at 1 week, 1 month, 3 months, 6 months, and 1 year. Information such as birth status, age, sex, preterm, mode of delivery, birth order, eczema history, personal allergy history, family allergy history, passive smoking, and place of residence (urban/rural) was collected. Total serum IgE level, serum allergen testing, routine blood tests, C-reactive protein level, procalcitonin level, respiratory pathogens tests, sputum culture, chest radiography or computed tomography were performed in all patients. The correlation between each factor and wheezing recurrence was evaluated. A total of 259 children were included in the study. They were divided into single recurrence, multiple recurrences, and no recurrence groups. The recurrence rate of wheezing was 56.8% (30.5% had a single recurrence and 26.3% had 2 or more recurrences). The percentage of children with a personal allergy history in the multiple recurrences group was significantly higher than in the single recurrence and no recurrence groups ( P = 0.031 and 0.008, respectively). The age of the children in the multiple recurrences group was significantly lower than that in the single recurrence group ( P < 0.001). Clinical severity scores were higher in the multiple recurrences group than in the single recurrence and no recurrence groups ( P = 0.002 and <0.001, respectively). Most children did not experience multiple recurrent wheezing. Children with young age, serious condition, and allergic constitution were prone to recurrent wheezing.

Factors associated with wheezing among Lebanese children: Results of a cross-sectional study

BACKGROUND

In Lebanon, asthma is underdiagnosed due to low access to healthcare, particularly in rural areas, although asthma diagnosis in children is based mainly on clinical symptoms. Thus, wheezing might be more suggestive of undiagnosed respiratory diseases including asthma in Lebanese children. This study aimed to determine the factors associated with wheezing in Lebanese children without asthma diagnosis.

METHODS

This cross-sectional study was conducted between December 2015 and April 2016, enrolling a total of 1203 schoolchildren.

RESULTS

Out of 1500 prepared questionnaires, 1380 questionnaires were distributed in schools, and 1203 (87.17%) were collected back from the parents of children aged between 4-17 years old. The sample included 42 (3.5%) [95% CI 0.025-0.045] children with reported chronic wheezing. A multivariable analysis was performed taking the presence versus absence of wheezing in children as the dependent variable. The results showed that spraying pesticides at home (aOR=1.91), presence of humidity at home (aOR=2.21) and child reflux (aOR=2.60) were significantly associated with the presence of wheezing in children.

CONCLUSION

The findings of the study suggest that certain environmental factors, such as pesticides, humidity at home and reflux disease, might be associated with wheezing episodes in children. Those factors can be prevented through raising awareness by health care professionals.

Preschool Wheezing: Trajectories and Long-Term Treatment

Wheezing is very common in infancy affecting one in three children during the first 3 years of life. Several wheeze phenotypes have been identified and most rely on temporal pattern of symptoms. Assessing the risk of asthma development is difficult. Factors predisposing to onset and persistence of wheezing such as breastfeeding, atopy, indoor allergen exposure, environmental tobacco smoke and viral infections are analyzed. Inhaled corticosteroids are recommended as first choice of controller treatment in all preschool children irrespective of phenotype, but they are particularly beneficial in terms of fewer exacerbations in atopic children. Other therapeutic options include the addition of montelukast or the intermittent use of inhaled corticosteroids. Overuse of inhaled steroids must be avoided. Therefore, adherence to treatment and correct administration of the medications need to be checked at every visit.

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.

Question 4: Is there a role for antibiotics in infantile wheeze?

Acute wheezing episodes are frequent in young children and are associated with high morbidity and healthcare utilization. The role of respiratory viruses in triggering acute wheezing is well known. There is also accumulating evidence that airway bacteria, either alone or as part of bacteria-virus interaction, are important determinants of acute asthma exacerbations. Targeting airway bacteria with antibiotics to reduce the severity of acute wheezing episodes and prevent recurrent wheezing among preschool children has been recently evaluated in three randomized, double-blind, placebo-controlled trials. The results of these studies are controversial. An interventional approach with azithromycin in young children during acute wheezing episodes cannot be generically incorporated into clinical practice, due to the potential consequences of widespread use of antibiotics in such a common clinical setting. This intervention may be reserved for children with really severe, recurrent wheezing episodes. Future research should focus on risk factors that facilitate acquisition of bacterial airway infection in young children and better understanding how virus and bacteria interact with each other during wheezing attacks. Identifying objective biomarkers that may direct the treatment to specific groups of children may represent a significant step forward in the clinical approach of acute wheezing.

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.

Special Considerations in Preschool Age

The diagnosis of asthma can be particularly difficult in young children, in whom wheezing is not always synonym with asthma. It is also difficult to predict which preschool children with wheeze will go on to be true asthmatics. In this chapter, we will characterize preschool wheezing and asthma and discuss early risk factors for the development of severe asthma. We will also review risk factors for severe acute wheezing in young children. Finally, we will describe the natural history and prognosis of wheezing and some of the attempts at early identification of children who will develop severe asthma.

Blood Biomarkers of Sensitization and Asthma

Biomarkers are essential to determine different phenotypes of childhood asthma, and for the prediction of response to treatments. In young preschool children with asthma, aeroallergen sensitization, and blood eosinophil count of 300/μL or greater may identify those who can benefit from the daily use of inhaled corticosteroids (ICS). We propose that every preschool child who is considered for ICS treatment should have these two features measured as a minimum before a decision is made on the commencement of long-term preventive treatment. In practice, IgE-mediated sensitization should be considered as a quantifiable variable, i.e., we should use the titer of sIgE antibodies or the size of skin prick test response. A number of other blood biomarkers may prove useful (e.g., allergen-specific IgG/IgE antibody ratios amongst sensitized individuals, component-resolved diagnostics which measures sIgE response to a large number of allergenic molecules, assessment of immune responses to viruses, level of serum CC16, etc.), but it remains unclear whether these can be translated into clinically useful tests. Going forward, a more integrated approach which takes into account multiple domains of asthma, from the pattern of symptoms and blood biomarkers to genetic risk and lung function measures, is needed if we are to move toward a stratified approach to asthma management.

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.

Early-life exposure to household chemicals and wheezing in children

The prevalence of the asthmatic symptoms among children increases globally over the time. Reduced exposure to pathogens in early childhood and increased exposure to anthropogenic irritants result in increased risk of wheezing in children, and all of this may be related to the usage of household chemicals. Objective of this analysis thus was to study the potential effects of overall exposure to home chemicals in the early life on the phenotypes of wheezing from birth until five years of age. 3411 mother-infant pairs from the Czech part of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC-CZ) participated in the study. The exposure was estimated by the composite household chemical score from 18 chemical-based products. Social, medical and environmental factors were taken into account as covariates in multivariable multinomial logistic regression using phenotypes of wheezing as a study outcome. We were able to determine the association between several wheezing childhood phenotypes and the frequent usage of household chemicals in the fully adjusted model. Statistically significant odds ratios (OR) for increasing exposures per 1 SD of exposure score were obtained for the intermediate onset transient (OR 1.27, 95% CI 1.10-1.47), intermediated onset persistent (OR 1.23, 95% CI 1.03-1.46), and early onset persistent phenotypes (OR 1.36, 95% CI 1.04-1.77) in comparison to never wheezing children. Moreover, the persistent phenotypes were significantly associated with school age asthma. Our study has shown the negative role of the increased household chemicals usage on the respiratory outcomes in children up to five years of age. Overall evaluation of the household chemical exposure may be useful tool for any large epidemiological studies.

Clinical and Pathologic Factors Predicting Future Asthma in Wheezing Children. A Longitudinal Study

Wheeze is a common symptom in infants, but not all wheezers develop asthma. Indeed, up to 50% of wheezing children outgrow their symptoms by school age. How to predict if early wheeze will become asthma is still a matter of vivid debate. In this work, we sought to assess the clinical and pathological factors that might predict the future development of asthma in children. Eighty children (mean age 3.8 ± 1 yr) who underwent a clinically indicated bronchoscopy were followed prospectively for a median of 5 years. At baseline, clinical characteristics with a particular focus on wheezing and its presentation (episodic or multitrigger) were collected, and structural and inflammatory changes were quantified in bronchial biopsies. Follow-up data were available for 74 of the 80 children. Children who presented with multitrigger wheeze were more likely to have asthma at follow-up than those with episodic wheeze (P = 0.04) or without wheeze (P < 0.0001). Children with asthma also had lower birth weights (P = 0.02), a lower prevalence of breastfeeding (P = 0.02), and a trend for increased IgE (P = 0.07) at baseline than those with no asthma. Basement membrane thickness and airway eosinophils at baseline were increased in children who developed asthma at follow-up (P = 0.001 and P = 0.026, respectively). Multivariate analysis showed that among all clinical and pathological factors, multitrigger wheezing, basement membrane thickening, and reduced birth weight were predictive of future asthma development. We conclude that multitrigger wheeze and reduced birth weight are clinical predictors of asthma development. Basement membrane thickening in early childhood is closely associated with asthma development, highlighting the importance of airway remodeling in early life as a risk factor for future asthma.

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.

Individual risk assessment tool for school-age asthma prediction in UK birth cohort

Background

Current published asthma predictive tools have moderate positive likelihood ratios (+LR) but high negative likelihood ratios (−LR) based on their recommended cut‐offs, which limit their clinical usefulness.

Objective

To develop a simple clinically applicable asthma prediction tool within a population‐based birth cohort.

Method

Children from the Manchester Asthma and Allergy Study (MAAS) attended follow‐up at ages 3, 8 and 11 years. Data on preschool wheeze were extracted from primary‐care records. Parents completed validated respiratory questionnaires. Children were skin prick tested (SPT). Asthma at 8/11 years (school‐age) was defined as parentally reported (a) physician‐diagnosed asthma and wheeze in the previous 12 months or (b) ≥3 wheeze attacks in the previous 12 months. An asthma prediction tool (MAAS APT) was developed using logistic regression of characteristics at age 3 years to predict school‐age asthma.

Results

Of 336 children with physician‐confirmed wheeze by age 3 years, 117(35%) had school‐age asthma. Logistic regression selected 5 significant risk factors which formed the basis of the MAAS APT: wheeze after exercise; wheeze causing breathlessness; cough on exertion; current eczema and SPT sensitisation(maximum score 5). A total of 281(84%) children had complete data at age 3 years and were used to test the MAAS APT. Children scoring ≥3 were at high risk of having asthma at school‐age (PPV > 75%; +LR 6.3, −LR 0.6), whereas children who had a score of 0 had very low risk(PPV 9.3%; LR 0.2).

Conclusion

MAAS APT is a simple asthma prediction tool which could easily be applied in clinical and research settings.

The all age asthma cohort (ALLIANCE) - from early beginnings to chronic disease: a longitudinal cohort study

Background

Asthma and wheezing disorders in childhood and adulthood are clinically heterogeneous regarding disease presentation, natural course, and response to treatment. Deciphering common disease mechanisms in distinct subgroups requires harmonized molecular (endo-) phenotyping of both children and adult patients with asthma in a prospective, longitudinal setting.

Methods

The ALL Age Asthma Cohort (ALLIANCE) of the German Center for Lung Research (DZL) is a prospective, multi-center, observational cohort study with seven recruiting sites across Germany. Data are derived from four sources: (a) patient history from medical records, (b) standardized questionnaires and structured interviews, (c) telephone interviews, and (d) objective measurements. Objective measurements include amongst others lung function and quantitative assessment of airway inflammation and exhaled breath, peripheral blood, skin, nasal, pharyngeal, and nasopharyngeal swabs, nasal secretions, primary nasal epithelial cells, and induced sputum. In cases, objective measurements and biomaterial collection are performed regularly, while control subjects are only examined once at baseline.

Discussion

The standardized and detailed collection of epidemiological and physiological data, and the molecular deep phenotyping of a comprehensive range of biomaterials in a considerable number of study participants across all ages are the outstanding characteristics of this multi-center cohort. Despite extensive biomaterial sampling, and a recruitment strategy that also includes pre-school children as young as 6 months, attrition is low. In children 83.9%, and in adults 90.5% attended the 12-month follow-up. The earliest time-point to include cases, however, is disease manifestation. Therefore, unraveling mechanisms that drive disease onset is limited, as this question can only be answered in a population-based birth cohort. Nonetheless, ALLIANCE offers a unique, integrative and inter-disciplinary framework with a comprehensive molecular approach in a prospective and identical fashion across ages in order to identify biomarkers and predictors for distinct childhood wheeze and asthma trajectories as well as their further course during adulthood. Ultimately, this approach aims to translate its most significant findings into clinical practice, and to improve asthma transition from adolescence to adulthood.

Trial registration

NCT02496468 for pediatric arm, NCT02419274 for adult arm.

Asthma Endotyping and Biomarkers in Childhood Asthma

Childhood asthma represents a heterogeneous challenging disease, in particular in its severe forms. The identification of different asthma phenotypes has stimulated research in underlying molecular mechanisms, such as the endotypes, and paved the way to the search for related specific biomarkers, which may guide diagnosis, management, and predict response to treatment. A limited number of biomarkers are currently available in clinical practice in the pediatric population, mostly reflecting type 2-high airway inflammation. The identification of biomarkers of childhood asthma is an active area of research that holds a potential great clinical utility and may represent a step forward toward tailored management and therapy: the so-called Precision Medicine. The aim of the present review is to provide an updated overview of asthma endotyping, mostly focusing on novel noninvasive biomarkers in childhood asthma.

Meta-analysis of prevalence of wheezing and recurrent wheezing in infants

BACKGROUND

Wheezing affects children's quality of life, and is related with asthma in childhood. Although prevalence of wheezing has been previously studied in several countries, there is no reference of worldwide prevalence in infants. The aim of this meta-analysis is to estimate the prevalence of wheezing and recurrent wheezing in infants aged up to two years, and compare the prevalence across world regions.

METHODS

Literature search was conducted in MEDLINE and SCOPUS databases, looking for observational studies published up to June 2016, including as keywords "prevalence" or "epidemiology" combined with "wheeze", "wheezing" or "asthma symptoms" and "infant" or "preschool". Fast*Pro software and random effects Bayesian model were used. Heterogeneity was estimated using I² statistic, and sensitivity analyses were performed.

RESULTS

We identified 109 studies after duplicates were removed. After exclusions, 14 studies were included in the meta-analysis. Prevalence of wheezing and recurrent wheezing were 36.06% (95% CI 35.17-36.96), and 17.41% (95% CI 16.74-18.09), respectively. In European countries, prevalence of wheezing was 30.68% (95% CI 28.97-32.45), and 12.35% (95% CI 11.27-13.47) for recurrent wheezing. Prevalence of wheezing and recurrent wheezing in Latin America were higher, 40.55% (95% CI 39.40-41.71), and 19.27% (95% CI 18.44-20.11), respectively. In Africa, prevalence of wheezing was 15.97% (95% CI 14.05-18.00). Low or no heterogeneity was found in all cases.

CONCLUSIONS

More than one third of infants suffer from wheezing and almost one fifth from recurrent wheezing, being these illnesses especially prevalent in Latin American countries, pointing out an important public health problem.

The cost-effectiveness of hypertonic saline inhalations for infant bronchiolitis: a decision analysis

BACKGROUND

This study evaluated the cost-effectiveness of hypertonic saline (HS) inhalations for infant bronchiolitis, compared to normal saline inhalations or standard treatment without inhalations as controls.

METHODS

The decision tree in the decision analysis was used to calculate the expected costs. Actual cost data were obtained from our retrospective case-control study on bronchiolitis treatment. The effectiveness of treatment, based on the hospitalization rate of those admitted to the emergency department and the length of stay (LOS) of those who were hospitalized, was collected from previous studies. For the effectiveness estimations, we made a meta-analysis summarizing the results of the meta-analysis of the Cochrane review in 2013 and the results of 10 studies published after it.

RESULTS

The mean hospitalization rate was 24.7% in the HS inhalation group and 32.6% in the control group [risk ratio: 0.80, 95% confidence interval (CI) 0.67-0.96] and the mean LOS was 3.736 (HS group) and 4.292 (controls) days (mean difference: - 0.55 days, 95% CI - 0.96 to - 0.15), respectively. The expected costs per patient, when both inpatients and outpatients were included, were €816 ($1111) in the HS inhalation group and €962 ($1310) in the control group. The expected costs per hospitalization, when only inpatients were included, were €2600 ($3540) in the HS inhalation group and €2890 ($3935) in the control group.

CONCLUSIONS

HS inhalations slightly reduced the expected hospitalization costs of infant bronchiolitis. However, the low effectiveness, rather than the cost, is the factor that will limit the use of HS inhalations in infant bronchiolitis.

Recurrent wheezing in neonatal pneumonia is associated with combined infection with Respiratory Syncytial Virus and Staphylococcus aureus or Klebsiella pneumoniae

Both viral and bacterial infections can be associated with wheezing episodes in children; however, information regarding combined infections with both viral and bacterial pathogens in full term neonates is limited. We sought to investigate the effects of viral–bacterial codetection on pneumonia severity and recurrent wheezing. A retrospective cohort study was conducted on neonates admitted to our hospital with pneumonia from 2009 to 2015. Of 606 total cases, 341 were diagnosed with RSV only, and 265 were diagnosed with both RSV and a potential bacterial pathogen. The leading four species of bacteria codetected with RSV were Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Enterobacter cloacae. Neonates with RSV and a potential bacterial pathogen were significantly more likely to have worse symptoms, higher C-reactive protein values and more abnormal chest x-ray manifestations with Bonferroni correction for multiple comparisons (P < 0.01). On Cox regression analysis, an increased risk of recurrent wheezing was found for neonates positive for RSV–Staphylococcus aureus and RSV–Klebsiella pneumoniae. Our findings indicate that the combination of bacteria and RSV in the neonatal airway is associated with more serious clinical characteristics. The presence of RSV and Staphylococcus aureus or Klebsiella pneumoniae may provide predictive markers for wheeze.

Stability and predictiveness of multiple trigger and episodic viral wheeze in preschoolers

BACKGROUND

In 2008, the European Respiratory Society Task Force proposed the terms multiple-trigger wheeze (MTW) and episodic (viral) wheeze (EVW) for children with wheezing episodes. We determined MTW and EVW prevalence, their 24-month stability and predictiveness for asthma.

METHODS

In total, 565 preschoolers (1-, 2- and 3-year-olds) in primary care with respiratory symptoms were followed until the age of 6 years when asthma was diagnosed. MTW status and EVW status were determined using questionnaire data collected at baseline and after one and 2 years. We distinguished 3 phenotypes and determined their 24-month stability, also accounting for treatment with inhaled corticosteroids (ICS). Logistic regression was used to analyse the phenotypes' associations with asthma.

RESULTS

Two hundred and eighty-one children had complete information. MTW and EVW were stable in 10 of 281 (3.6%) and 24 of 281 (8.5%), respectively. The odds of developing asthma for children with stable MTW and stable EVW were 14.4 (1.7-119) and 3.6 (1.2-11.3) times greater than those for children free of wheeze (for at least 1 year). ICS was associated with increased stability of MTW and EVW.

CONCLUSIONS

Stable multiple-trigger and stable episodic viral wheeze are relatively uncommon. However, 1- to 3-year-olds with stable MTW are at much increased risk of asthma.

Recurrent wheeze and its relationship with lung function and airway inflammation in preschool children: a cross-sectional study in South Korea

BACKGROUND

Relationship between recurrent wheeze and airway function and inflammation in preschool children is not fully known.

OBJECTIVE

To investigate the relationship between recurrent wheeze and airway inflammation, lung function, airway hyper-reactivity (AHR) and atopy in preschool children.

DESIGN

Observational study, comparing forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) and mid-forced expiratory flow (FEF_25%-75%), dose-response slope (DRS), exhaled nitric oxide (eNO) and atopic sensitisation between children with recurrent wheeze and those without.

SETTING

Population-based, cross-sectional study in Seoul and the Gyeonggi province of Korea conducted as a government-funded programme to perform standardised measurement of the prevalence of allergic diseases, and related factors, in preschool children.

PARTICIPANTS

900 children aged 4-6 years. PRIMARY AND SECONDARY OUTCOME MEASURES: eNO, FEV₁/FVC, FEF_25%-75%, DRS, atopic sensitisation and allergic diseases.

METHODS

Children completed the modified International Study of Asthma and Allergies in Childhood questionnaire and underwent eNO assessments, spirometry, methacholine bronchial provocation tests and skin prick tests. Recurrent wheeze was defined as having a lifetime wheeze of more than three episodes, based on the questionnaire. The frequency of hospitalisation and emergency room visits was also obtained by means of the questionnaire. 'Current' wheeze was defined as having symptoms or treatments within the past 12 months.

RESULTS

The prevalence of recurrent wheeze was 13.4%. Children with recurrent wheeze showed a higher prevalence of lifetime or current allergic rhinitis (p=0.01 and p=0.002, respectively) and lifetime atopic dermatitis (p=0.007). Children with recurrent wheeze showed lower FEV₁/FVC (p=0.033) and FEF_25%-75% (p=0.004), and higher eNO levels (p=0.013) than those without recurrent wheeze. However, the DRS, prevalence of atopic sensitisation and serum IgE levels were not significantly different between the two groups.

CONCLUSIONS

Recurrent wheeze in preschool children may be associated with airway inflammation and diminished airway function, but not with AHR or atopy.

Sensitization predicts asthma development among wheezing toddlers in secondary healthcare

INTRODUCTION

Some wheezing toddlers develop asthma later in childhood. Sensitization is known to predict asthma in birth cohorts. However, its predictive value in secondary healthcare is uncertain.

AIM

This study examines the predictive value of sensitization to inhalant allergens among wheezing toddlers in secondary healthcare for the development of asthma at school age (≥6 years).

METHODS

Preschool children (1-3 years) who presented with wheezing in secondary healthcare were screened on asthma at school age with the International Study of Asthma and Allergies in Childhood questionnaire. The positive and negative predictive value (PPV and NPV) of specific IgE to inhalant allergens (cut-off concentration 0.35 kU/L) and several non-invasive variables from a child's history (such as hospitalization, eczema, and parental atopy) were calculated. The additional predictive value of sensitization when combined with non-invasive predictors was examined in multivariate analysis and by ROC curves.

RESULTS

Of 116 included children, 63% developed asthma at school age. Sensitization to inhalant allergens was a strong asthma predictor. The odds ratio (OR), PPV and NPV were 7.4%, 86%, and 55%, respectively. Eczema (OR 3.4) and hospital admission (OR 2.6) were significant non-invasive determinants. Adding sensitization to these non-invasive predictors in multivariate analysis resulted in a significantly better asthma prediction. The area under the ROC curve increased from 0.70 with only non-invasive predictors to 0.79 after adding sensitization.

CONCLUSION

Sensitization to inhalant allergens is a strong predictor of school age asthma in secondary healthcare and has added predictive value when combined with non-invasive determinants. Pediatr Pulmonol. 2017;52:729-736. © 2017 Wiley Periodicals, Inc.

Sex discordance in asthma and wheeze prevalence in two longitudinal cohorts

Sex discordance in asthma prevalence has been previously reported, with higher prevalence in males before puberty, and in females after puberty; the adolescent "switch". However, cross-sectional studies have suggested a narrowing of this discordance in recent decades. We used a combination of cross-sectional and longitudinal modelling to examine sex differences in asthma, wheeze and longitudinal wheezing phenotypes in two UK birth cohorts, the Avon Longitudinal Study of Parents and Children (ALSPAC; born 1991-92 with data from age 0-18 years) and the Millennium Cohort Study (MCS; born 2000-02 with data from age 3-10 years). We derived measures of asthma and wheeze from questionnaires completed by mothers and cohort children. Previously-derived ALSPAC wheezing phenotype models were applied to MCS. Males had a higher prevalence of asthma at 10.7 years in ALSPAC (OR 1.45 95%CI: 1.26, 1.66 n = 7778 for current asthma) and MCS (OR 1.42 95%CI: 1.29, 1.56 n = 6726 for asthma ever) compared to females, decreasing in ALSPAC after puberty (OR 0.94 95%CI: 0.79, 1.11 n = 5023 for current asthma at 16.5 years). In longitudinal models using restricted cubic splines, males had a clear excess for asthma in the last 12 months and wheeze in the last 12 months up until 16.5 years of age in ALSPAC. Males had an increased risk of all derived longitudinal wheezing phenotypes in MCS when compared to never wheeze and no evidence of being at lower risk of late wheeze when compared to early wheeze. By comparing data in two large, contemporary cohorts we have shown the persistence of sex discordance in childhood asthma, with no evidence that the sex discordance is narrowing in recent cohorts.

Infantile wheeze: rethinking dogma

Wheeze is a common symptom in young children and is usually associated with viral illnesses. It is a major source of morbidity and is responsible for a high consumption of healthcare and economic resources worldwide. A few children have a condition resembling classical asthma. Rarer specific conditions may have a wheezy component and should be considered in the differential diagnosis. Over the last half century, there have been many circular discussions about the best way of managing preschool wheeze. In general, intermittent wheezing should be treated with intermittent bronchodilator therapy, and a controller therapy should be prescribed for a young child with recurrent wheezing only if positively indicated, and only then if carefully monitored for efficacy. Good multidisciplinary support, attention to environmental exposition and education are essential in managing this common condition. This article analyses the pathophysiological basis of wheezing in infancy and critically discusses the evolution of the scientific progress over time in this unique field of respiratory medicine.

Factors predicting persistence of early wheezing through childhood and adolescence: a systematic review of the literature

Background

For the early identification of persistent asthma symptoms among young children with recurrent wheezing, it would be helpful to identify all available studies that have identified at least one factor for predicting the persistence of early wheezing. The objective of the present study was to perform a systematic review of all studies that have identified factors that predict the persistence of symptoms among young patients with recurring wheezing.

Methods

A systematic review of relevant studies was conducted through searching in MEDLINE, EMBASE, CINHAL, and SCOPUS databases up to June 2016. Studies that identified predictors of persistence of wheezing illness among young children with recurrent wheezing were retrieved. Two independent reviewers screened the literature and extracted relevant data.

Results

The literature search returned 649 references, 619 of which were excluded due to their irrelevance. Five additional studies were identified from reference lists, and 35 studies were finally included in the review. Among all the identified predictors, the most frequently identified ones were the following: family asthma or atopy; personal history of atopic diseases; allergic sensitization early in life; and frequency, clinical pattern, or severity of wheezing/symptoms.

Conclusion

Parental asthma (especially maternal), parental allergy, eczema, allergic rhinitis, persistent wheezing, wheeze without colds, exercise-induced wheeze, severe wheezing episodes, allergic sensitization (especially polysensitization), eosinophils (blood or eosinophil cationic protein in nasal sample), and fraction of exhaled nitric oxide were risk factors predicting persistence of early wheezing through school age. All of them are included in conventional algorithms, for example, Asthma Predictive Index and its modifications, for predicting future asthma.

Asthma phenotypes in childhood

INTRODUCTION

Asthma is no longer thought of as a single disease, but rather a collection of varying symptoms expressing different disease patterns. One of the ongoing challenges is understanding the underlying pathophysiological mechanisms that may be responsible for the varying responses to treatment. Areas Covered: This review provides an overview of our current understanding of the asthma phenotype concept in childhood and describes key findings from both conventional and data-driven methods. Expert Commentary: With the vast amounts of data generated from cohorts, there is hope that we can elucidate distinct pathophysiological mechanisms, or endotypes. In return, this would lead to better patient stratification and disease management, thereby providing true personalised medicine.

Growth, Nutritional Status, and Pulmonary Function in Children with Chronic Recurrent Bronchitis

Bronchitis is a common health problem in children. Frequent bronchitis in infancy increases the risk of developing chronic respiratory diseases. The aim of the study was to assess the level of growth and the nutritional status in children and youths with special regard to the level of body fatness assessed by measuring skin-fold thickness. Relationships between somatic development, pulmonary function and the course of the disease were also explored. The study was carried out using anthropometric and spirometric measurements and also information on the severity and course of the disease in 141 children with chronic or recurrent bronchitis. All of the subjects were patients of the Pulmonary Medicine and Allergology Center in Karpacz, Poland. The mean body height did not differ significantly between the children examined and their healthy peers. However, the infection-prone children had excessive body fatness and muscle mass deficiency. The increased level of subcutaneous adipose tissue occurred especially in children with short duration of the disease, i.e. a maximum of 1 year. The functional lung parameters were generally normal. The presence of atopic diseases such as allergic rhinitis or atopic dermatitis did not impair the course of the children's somatic development. Also, long-term disease or the presence of additional allergic diseases did not impair lung function in the examined children. Taking appropriate preventive measures is recommended to achieve and maintain normal body weight in children who receive therapy due to bronchitis.

Asma infantil

El asma es la enfermedad crónica infantil más frecuente. El diagnóstico es fácil en la mayoría de las ocasiones por la aparición de episodios de disnea espiratoria con sibilancias reversibles espontáneamente o por el efecto de broncodilatadores. En el momento del diagnóstico, se requieren tres pruebas complementarias: las radiografías de tórax, las pruebas funcionales respiratorias y un estudio alergológico. El tratamiento de las exacerbaciones se basa en los beta2-adrenérgicos inhalados y, si es preciso, en la corticoterapia oral. El objetivo del tratamiento de fondo es mantener el control, prevenir las exacerbaciones y restaurar o mantener las funciones pulmonares normales. Se debe adaptar al nivel de control del asma y en él tiene un lugar destacado la corticoterapia inhalada y los broncodilatadores de acción prolongada. En los menores de tres años, el asma se diagnostica a partir de tres episodios de sibilancias. Se debe buscar la presencia de antecedentes particulares, de manifestaciones atípicas o persistentes y de anomalías en la radiografía de tórax para descartar las demás causas de manifestaciones sibilantes recidivantes. Cuando es necesario un tratamiento de fondo, se basa en la corticoterapia inhalada. Las cohortes prospectivas han permitido demostrar que la atopia, la gravedad clínica y la persistencia de una obstrucción clínica son los factores principales tanto de la persistencia como de la gravedad del asma durante la vida.

Post-bronchiolitis Use of Asthma Medication: A Prospective 1-year Follow-up Study

BACKGROUND

Our aim was to evaluate the association between viral findings during bronchiolitis and the use of asthma controller medication (primary outcome) and systemic corticosteroids (secondary outcome) during the first post-bronchiolitis year.

METHODS

We enrolled 408 children hospitalized for bronchiolitis at <24 months of age in a prospective, 3-center, 1-year follow-up study in Finland. Viruses were detected with polymerase chain reaction in nasopharyngeal aspirates. The parents underwent a structured interview during hospitalization. Twelve months later, the use of asthma medication was asked in a structured questionnaire. Multivariable logistic regression was used for statistical analysis.

RESULTS

In total, 365 (89%) children completed the 1-year follow-up. The use of long-term asthma controller medication was highest in the rhinovirus-positive group (61% vs. 15% in respiratory syncytial virus-positive group; adjusted odd ratios, 7.5; 95% confidence interval: 3.7-15.3), followed by children negative for both respiratory syncytial virus and rhinovirus (36%; adjusted odd ratios, 2.6; 95% confidence interval: 1.3-5.3). Likewise, rhinovirus etiology was associated with more courses of systemic corticosteroids during the follow-up. The main findings were similar in a subset of infants aged <12 months with first wheezing.

CONCLUSIONS

Children hospitalized for rhinovirus-positive bronchiolitis used long-term asthma controller medication more often than those hospitalized for rhinovirus-negative bronchiolitis during first year after hospitalization.

Risk Factors Associated with Irreversible Airway Obstruction in Asthma: A Systematic Review and Meta-Analysis

Irreversible airway obstruction (IAO) is a subtype of asthma and relates to poorer prognosis in some asthma patients. However, the prevalence and risk factors for IAO are unknown. A systematic review regarding controlled clinical studies (cohort, case-control studies) on IAO asthma in adult and/or children affected by asthma/early wheeze was performed. Eighteen papers were identified in this study. It was reported that the incidence of IAO at random effects or fixed effects in severe asthma and nonsevere asthma was 0.54 (95% CI: 0.45–0.62) and 0.16 (95% CI: 0.12–0.20), respectively. In IAO asthma, the pooled odds ratio (OR) related to smoking exposure was 2.22 (95% CI: 1.82–2.73), the OR for male, smoking, and fractional exhaled nitric oxide (FENO) was 2.22 (95% CI: 1.82–2.7), 1.79 (95% CI: 1.46–2.19), and 2.16 (95% CI: 1.05–4.43), respectively, suggesting these factors increase the risk of IAO. However, a decreased OR in IAO asthma was observed due to rhinitis (OR = 0.31, 95% CI: 0.24–0.40), atopy (OR = 0.584, 95% CI: 0.466–0.732), and atopic dermatitis (OR = 0.60, 95% CI: 0.42–0.85), indicating these factors are associated with reduced risk of IAO. IAO in asthma is associated with gender, smoking, FENO, rhinitis, atopy, and atopic dermatitis.

Predicting asthma outcomes

This review addresses predictors of remission or persistence of wheezing and asthma from early childhood through adulthood. Early childhood wheezing is common, but predicting who will remit or have persistent childhood asthma remains difficult. By adding parental history of asthma and selected infant biomarkers to the history of recurrent wheezing, the Asthma Predictive Index and its subsequent modifications provide better predictions of persistence than simply the observation of recurrent wheeze. Sensitization, especially to multiple allergens, increases the likelihood of development of classic childhood asthma. Remission is more likely in male subjects and those with milder disease (less frequent and less severe symptoms), less atopic sensitization, a lesser degree of airway hyperresponsiveness, and no concomitant allergic disease. Conversely, persistence is linked strongly to allergic sensitization, greater frequency and severity of symptoms, abnormal lung function, and a greater degree of airway hyperresponsiveness. A genetic risk score might predict persistence more accurately than family history. Remission of established adult asthma is substantially less common than remission during childhood and adolescence. Loss of lung function can begin early in life and tracks through childhood and adolescence. Despite therapy which controls symptoms and exacerbations, the outcomes of asthma appear largely resistant to pharmacologic therapy.

Intestinal microbiota composition after antibiotic treatment in early life: the INCA study

Background

The acquisition and development of infant gut microbiota can be influenced by numerous factors, of which early antibiotic treatment is an important one. However, studies on the effects of antibiotic treatment in early life on clinical outcomes and establishment and development of the gut microbiota of term infants are limited. Disturbed microbiota composition is hypothesized to be an underlying mechanism of an aberrant development of the immune system. This study aims to investigate the potential clinical and microbial consequences of empiric antibiotic use in early life.

Methods/Design

450 term born infants, of whom 150 are exposed to antibiotic treatment in early life and 300 are not (control group), are included in this observational cohort study with a one-year follow-up. Clinical outcomes, including coughing, wheezing, fever >38 °C, runny nose, glue ear, rash, diarrhea and >3 crying hours a day, are recorded daily by parents and examined by previously defined doctor’s diagnosis. A blood sample is taken at closure to investigate the infant’s vaccination response and sensitization for food and inhalant allergens. Fecal samples are obtained at eight time points during the first year of life. Potential differences in microbial profiles of infants treated with antibiotics versus healthy controls will be determined by use of 16S-23S rRNA gene analysis (IS-pro). Microbiota composition will be described by means of abundance, diversity and (dis)similarity. Diversity is calculated using the Shannon index. Dissimilarities between samples are calculated as the cosine distance between each pair of samples and analyzed with principal coordinate analysis. Clinical variables and possible associations are assessed by appropriate statistics.

Discussion

Both clinical quantitative and qualitative microbial effects of antibiotic treatment in early life may be demonstrated. These findings can be important, since there is evidence that manipulation of the infant microbiota by using pre- or probiotics can restore the ecological balance of the microbiota and may mitigate potential negative effects on the developing immune system, when use of antibiotics cannot be avoided.

Trial registration

ClinicalTrials.gov NCT02536560. Registered 28 August 2015.

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.

Gender differences in the relationship between body mass index (BMI) changes and the prevalence and severity of wheezing and asthma in the first year of life

BACKGROUND

Rapid weight gain has been recently associated with asthma at school age, but its influence in respiratory symptoms during infancy is still unknown.

METHODS

Answers from 6541 parents living in six different cities of Brazil to the International Study of Wheezing in Infants (EISL) questionnaire were analysed. Data from reported weight and height at birth and at one year were used to calculate BMI. Rapid body mass index (BMI) gain was defined by the difference in BMI superior to 1.0z and excessive by the difference superior to 2.0z.

RESULTS

Rapid BMI gain was found in 45.8% infants and excessive in 24.4%. Boys showed a significantly higher BMI gain than girls. Girls with rapid BMI gain showed a significantly higher prevalence of hospitalisation for wheezing (8.8% vs. 6.4%; aOR: 1.4, 95%CI: 1.1-1.8), severe wheezing (18.1% vs. 15.0%; aOR: 1.3, 95%CI: 1.0-1.5) and medical diagnosis of asthma (7.5% vs. 5.7%; aOR: 1.3, 95%CI: 1.0-1.7). Girls with excessive BMI gain also had a significantly higher prevalence of hospitalisation for wheezing (9.8% vs. 6.7%; aOR: 1.5, 95%CI: 1.1-2.0) and severe wheezing (18.9% vs. 15.5%; aOR: 1.3, 95%CI: 1.0-1.6). No significant association was found among boys.

CONCLUSIONS

The majority of the evaluated infants showed BMI gain above expected in the first year of life. Although more commonly found in boys, rapid and excessive BMI gain in the first year of life was significantly related to more severe patterns of wheezing in infancy among girls.

MLBCD: a machine learning tool for big clinical data

Background

Predictive modeling is fundamental for extracting value from large clinical data sets, or “big clinical data,” advancing clinical research, and improving healthcare. Machine learning is a powerful approach to predictive modeling. Two factors make machine learning challenging for healthcare researchers. First, before training a machine learning model, the values of one or more model parameters called hyper-parameters must typically be specified. Due to their inexperience with machine learning, it is hard for healthcare researchers to choose an appropriate algorithm and hyper-parameter values. Second, many clinical data are stored in a special format. These data must be iteratively transformed into the relational table format before conducting predictive modeling. This transformation is time-consuming and requires computing expertise.

Methods

This paper presents our vision for and design of MLBCD (Machine Learning for Big Clinical Data), a new software system aiming to address these challenges and facilitate building machine learning predictive models using big clinical data.

Results

The paper describes MLBCD’s design in detail.

Conclusions

By making machine learning accessible to healthcare researchers, MLBCD will open the use of big clinical data and increase the ability to foster biomedical discovery and improve care.