Clinical and epidemiologic phenotypes of childhood asthma

Novel Approach to Identify Severe Maternal Morbidity Clusters: A Latent Class Analysis

Whether clusters exist within severe maternal morbidity (SMM), a set of life-threatening heterogeneous conditions, is not known. Our primary objective was to identify SMM clusters using a data-driven clustering technique, their associated predictors and outcomes.From 2008 to 2017, we used a delivery database supplemented by state data and medical record abstraction from a single institution in Pennsylvania. To identify SMM clusters, we applied latent class modeling that included 23 conditions defined by 21 Centers for Disease Control SMM indicators, intensive care unit (ICU) admission, or prolonged postpartum length of stay. Logistic regression models estimated risk for SMM clusters and associations between clusters and maternal and neonatal outcomes.Among 97,492 deliveries, 2.7% (N = 2,666) experienced SMM by any of the 23 conditions. Four clusters were identified as archetypes of SMM. Deliveries labeled as Hemorrhage (37.7%, N = 1,004) were characterized by blood transfusions and sickle cell anemia; Critical Care (28.1%, N = 748) by ICU admission and amniotic embolism; Vascular (24.5%, N = 654) by cerebrovascular conditions; and Shock (9.8%, N = 260) by ventilatory support and shock. Hypertensive disorders of pregnancy, depression, and Medicaid insurance were associated with Shock cluster. People in all clusters had a high risk of maternal death within 1 year (odds ratio: 12.0, 95% confidence interval: 6.2-23). Infants born to those in the shock cluster had the highest odds of neonatal death, low Apgar scores, and neonatal ICU admission.We identified four novel SMM clusters that may help understand the collection of conditions defining SMM, underlying pathways and the importance of comorbidities such as depression and social determinants of health markers that amplify the well-established risk factors for SMM such as hypertensive disorders of pregnancy. · A total of 2.7% of deliveries experienced SMM events.. · There are four distinct SMM clusters: Hemorrhage, Critical Care, Vascular, and Shock.. · Not all SMM clusters bear the same risk for adverse perinatal outcomes..

Survey Health Data on Allergic Rhinitis (AR) and Asthmatic Symptoms and Blood Samples (IgE Sensitizations) in Preschool Children: An Observational Study

BACKGROUND

Aim of the study was to investigate the association of IgE sensitizations in serum and self-reported allergic rhinitis (AR) and asthmatic symptoms.

METHODS

Between 2015 and 2018, parents of 1190 children in Günzburg, Germany participated in the study by completing a questionnaire. Settings were the Health-Monitoring-Units (HMU) during the obligatory school entry examinations and a medical examination for all German children at the age of 60-64 months (U9). Random serum samples from 340 children were analyzed for IgE-sensitizations. For possible associations of sensitization and six health outcomes (symptoms of AR, dry cough at night, wheeze, asthma diagnosis, physician-diagnosed asthma, and physician-diagnosed AR), a regression analysis was performed.

RESULTS

The parents of 1190 children completed the questionnaire. Parental asthma and physician-diagnosed asthma (OR 4.79; 95%-CI [2.16-10.65]) and underweight at birth/preterm delivery showed the highest associations with asthma based on the German ISAAC definition (OR 3.58; 95%-CI [1.77-7.22]). Out of 340 children blood samples 118 children were sensitized against at least one allergen (airborne pollen allergens, non-seasonal airborne allergens, or food allergens). Sensitized children reported more frequently from symptoms of AR, wheeze, and asthma based on the German ISAAC definition than children without sensitization.

CONCLUSION

This observational study identified the prevalence of AR, asthma and existing sensitization among the participating children. Parental asthma and underweight at birth were identified as risk factors for allergic symptoms and asthma.

Computational Phenotyping of Obstructive Airway Diseases: A Systematic Review

Introduction

Computational sciences have significantly contributed to characterizing airway disease phenotypes, complementing medical expertise. However, comparing studies that derive phenotypes is challenging due to varying decisions made during phenotyping. We conducted a systematic review to describe studies that utilized unsupervised computational approaches for phenotyping obstructive airway diseases in children and adults.

Methods

We searched for relevant papers published between 2010 and 2020 in PubMed, EMBASE, Scopus, Web of Science, and Google Scholar. Additional sources included conference proceedings, reference lists, and expert recommendations. Two reviewers independently screened studies for eligibility, extracted data, and assessed study quality. Disagreements were resolved by a third reviewer. An in-house quality appraisal tool was used. Evidence was synthesized, focusing on populations, variables, and computational approaches used for deriving phenotypes.

Results

Of 120 studies included in the review, 60 focused on asthma, 19 on severe asthma, 28 on COPD, 4 on asthma-COPD overlap (ACO), and 9 on rhinitis. Among asthma studies, 31 focused on adults and 9 on children, with phenotypes related to atopy, age at onset, and disease severity. Severe asthma phenotypes were characterized by symptomatology, atopy, and age at onset. COPD phenotypes involved lung function, emphysematous changes, smoking, comorbidities, and daily life impairment. ACO and rhinitis phenotypes were mostly defined by symptoms, lung function, and sensitization, respectively. Most studies used hierarchical clustering, with some employing latent class modeling, mixture models, and factor analysis. The comprehensiveness of variable reporting was the best quality indicator, while reproducibility measures were often lacking.

Conclusion

Variations in phenotyping methods, study settings, participant profiles, and variables contribute to significant differences in characterizing asthma, severe asthma, COPD, ACO, and rhinitis phenotypes across studies. Lack of reproducibility measures limits the evaluation of computational phenotyping in airway diseases, underscoring the need for consistent approaches to defining outcomes and selecting variables to ensure reliable phenotyping.

Machine learning-derived asthma and allergy trajectories in children: a systematic review and meta-analysis

INTRODUCTION

Numerous studies have characterised trajectories of asthma and allergy in children using machine learning, but with different techniques and mixed findings. The present work aimed to summarise the evidence and critically appraise the methodology.

METHODS

10 databases were searched. Screening, data extraction and quality assessment were performed in pairs. Trajectory characteristics were tabulated and visualised. Associated risk factor and outcome estimates were pooled using a random-effects meta-analysis.

RESULTS

89 studies were included. Early-onset (infancy) persistent, mid-onset (∼2-5 years) persistent, early-onset early-resolving (within ∼2 years) and early-onset mid-resolving (by ∼3-6 years) wheezing and eczema, respectively, were the most commonly identified disease trajectories. Intermediate/transient trajectories were rare. Male sex was associated with a higher risk of most wheezing trajectories and possibly with early-resolving eczema, while being slightly protective against mid-onset persistent eczema. Parental disease/genetic markers were associated with persistent trajectories of wheezing and eczema, respectively. Prenatal (and less so postnatal) tobacco smoke exposure was associated with most wheezing trajectories, as were lower respiratory tract infections in infancy (particularly with the early-onset resolving patterns). Most studies (69%) were of low methodological quality (particularly in modelling approaches and reporting). Few studies investigated allergic multimorbidity, allergic rhinitis and food allergy.

CONCLUSIONS

Childhood asthma/wheezing and eczema can be characterised by a few relatively consistent trajectories, with some actionable risk factors such as pre-/postnatal smoke exposure. Improved computational methodology is warranted to better assess generalisability and elucidate the validity of intermediate/transient trajectories. Likewise, allergic multimorbidity and trajectories of allergic rhinitis and food allergy need to be further elucidated.

Prenatal polycyclic aromatic hydrocarbon exposure and asthma at age 8-9 years in a multi-site longitudinal study

BACKGROUND AND AIM

Studies suggest prenatal exposure to polycyclic aromatic hydrocarbons (PAHs) may influence wheezing or asthma in preschool-aged children. However, the impact of prenatal PAH exposure on asthma and wheeze in middle childhood remain unclear. We investigated these associations in socio-demographically diverse participants from the ECHO PATHWAYS multi-cohort consortium.

METHODS

We included 1,081 birth parent-child dyads across five U.S. cities. Maternal urinary mono-hydroxylated PAH metabolite concentrations (OH-PAH) were measured during mid-pregnancy. Asthma at age 8-9 years and wheezing trajectory across childhood were characterized by caregiver reported asthma diagnosis and asthma/wheeze symptoms. We used logistic and multinomial regression to estimate odds ratios of asthma and childhood wheezing trajectories associated with five individual OH-PAHs, adjusting for urine specific gravity, various maternal and child characteristics, study site, prenatal and postnatal smoke exposure, and birth year and season in single metabolite and mutually adjusted models. We used multiplicative interaction terms to evaluate effect modification by child sex and explored OH-PAH mixture effects through Weighted Quantile Sum regression.

RESULTS

The prevalence of asthma in the study population was 10%. We found limited evidence of adverse associations between pregnancy OH-PAH concentrations and asthma or wheezing trajectories. We observed adverse associations between 1/9-hydroxyphenanthrene and asthma and persistent wheeze among girls, and evidence of inverse associations with asthma for 1-hydroxynathpthalene, which was stronger among boys, though tests for effect modification by child sex were not statistically significant.

CONCLUSIONS

In a large, multi-site cohort, we did not find strong evidence of an association between prenatal exposure to PAHs and child asthma at age 8-9 years, though some adverse associations were observed among girls.

The impact of perinatal and at birth risk factors on the progression from preschool wheezing to adolescent asthma

Asthma is a global health concern affecting millions of children and adolescents. This review focuses on the possible factors that are associated with the transition from preschool wheezing to childhood asthma and highlights the significance of early-life environmental exposures during pregnancy and the first 6 months of life in shaping allergies and asthma. We observed a scarcity of studies investigating this subgroup, with most focusing on wheezing trajectories. We undertook a thorough investigation of diverse perinatal exposures that have the potential to impact this transition. These factors include maternal asthma, smoking during pregnancy, diet, prepregnancy weight, infant birthweight, gestational age, and breastfeeding. Although limited, studies do suggest that maternal asthma increases the likelihood of preschool wheeze in offspring that persists through childhood with potential asthma progression. Findings concerning other perinatal exposures remain inconsistent. Further research is needed to identify asthma progression risk factors and assess perinatal exposure effects.

Phenotypic characteristics, healthcare use, and treatment in children with night cough compared with children with wheeze

OBJECTIVES

Population-based studies of children with dry night cough alone compared with those who also wheeze are few and inconclusive. We compared how children with dry night cough differ from those who wheeze.

METHODS

LuftiBus in the school is a population-based study of schoolchildren conducted between 2013 and 2016 in Zurich, Switzerland. We divided children into four mutually exclusive groups based on reported dry night cough (henceforth referred as "cough") and wheeze and compared parent-reported symptoms, comorbidities, exposures, FeNO, spirometry, and healthcare use and treatment.

RESULTS

Among 3457 schoolchildren aged 6-17 years, 294 (9%) reported "cough," 181 (5%) reported "wheeze," 100 (3%) reported "wheeze and cough," and 2882 (83%) were "asymptomatic." Adjusting for confounders in a multinomial regression, children with "cough" reported more frequent colds, rhinitis, and snoring than "asymptomatic" children; children with "wheeze" or "wheeze and cough" more often reported hay fever, eczema, and parental histories of asthma. FeNO and spirometry were similar among "asymptomatic" and children with "cough," while children with "wheeze" or "wheeze and cough" had higher FeNO and evidence of bronchial obstruction. Children with "cough" used healthcare less often than those with "wheeze," and they attended mainly primary care. Twenty-two children (7% of those with "cough") reported a physician diagnosis of asthma and used inhalers. These had similar characteristics as children with wheeze.

CONCLUSION

Our representative population-based study confirms that children with dry night cough without wheeze clearly differed from those with wheeze. This suggests asthma is unlikely, and they should be investigated for alternative aetiologies, particularly upper airway disease.

From preschool wheezing to asthma: Environmental determinants

Wheezing is common among preschool children, representing a group of highly heterogeneous conditions with varying natural history. Several phenotypes of wheezing have been proposed to facilitate the identification of young children who are at risk of subsequent development of asthma. Epidemiological and immunological studies across different populations have revealed the key role of environmental factors in influencing the progression from preschool wheezing to childhood asthma. Significant risk factors include severe respiratory infections, allergic sensitization, and exposure to tobacco smoke. In contrast, a farming/rural environment has been linked to asthma protection in both human and animal studies. Early and intense exposures to microorganisms and microbial metabolites have been demonstrated to alter host immune responses to allergens and viruses, thereby driving the trajectory away from wheezing illness and asthma. Ongoing clinical trials of candidate microbes and microbial products have shown promise in shaping the immune function to reduce episodes of viral-induced wheezing. Moreover, restoring immune training may be especially important for young children who had reduced microbial exposure due to pandemic restrictions. A comprehensive understanding of the role of modifiable environmental factors will pave the way for developing targeted prevention strategies for preschool wheezing and asthma.

Current state and prospects of artificial intelligence in allergy

The field of medicine is witnessing an exponential growth of interest in artificial intelligence (AI), which enables new research questions and the analysis of larger and new types of data. Nevertheless, applications that go beyond proof of concepts and deliver clinical value remain rare, especially in the field of allergy. This narrative review provides a fundamental understanding of the core concepts of AI and critically discusses its limitations and open challenges, such as data availability and bias, along with potential directions to surmount them. We provide a conceptual framework to structure AI applications within this field and discuss forefront case examples. Most of these applications of AI and machine learning in allergy concern supervised learning and unsupervised clustering, with a strong emphasis on diagnosis and subtyping. A perspective is shared on guidelines for good AI practice to guide readers in applying it effectively and safely, along with prospects of field advancement and initiatives to increase clinical impact. We anticipate that AI can further deepen our knowledge of disease mechanisms and contribute to precision medicine in allergy.

GEMA 5.3. Spanish Guideline on the Management of Asthma

The Spanish Guideline on the Management of Asthma, better known by its acronym in Spanish GEMA, has been available for more than 20 years. Twenty-one scientific societies or related groups both from Spain and internationally have participated in the preparation and development of the updated edition of GEMA, which in fact has been currently positioned as the reference guide on asthma in the Spanish language worldwide. Its objective is to prevent and improve the clinical situation of people with asthma by increasing the knowledge of healthcare professionals involved in their care. Its purpose is to convert scientific evidence into simple and easy-to-follow practical recommendations. Therefore, it is not a monograph that brings together all the scientific knowledge about the disease, but rather a brief document with the essentials, designed to be applied quickly in routine clinical practice. The guidelines are necessarily multidisciplinary, developed to be useful and an indispensable tool for physicians of different specialties, as well as nurses and pharmacists. Probably the most outstanding aspects of the guide are the recommendations to: establish the diagnosis of asthma using a sequential algorithm based on objective diagnostic tests; the follow-up of patients, preferably based on the strategy of achieving and maintaining control of the disease; treatment according to the level of severity of asthma, using six steps from least to greatest need of pharmaceutical drugs, and the treatment algorithm for the indication of biologics in patients with severe uncontrolled asthma based on phenotypes. And now, in addition to that, there is a novelty for easy use and follow-up through a computer application based on the chatbot-type conversational artificial intelligence (ia-GEMA).

Childhood asthma phenotypes and endotypes: a glance into the mosaic

BACKGROUND

Asthma is an inflammatory lung disease that constitutes the most common noncommunicable chronic disease in childhood. Childhood asthma shows large heterogeneity regarding onset of disease, symptoms, severity, prognosis, and response to therapy.

MAIN BODY

Evidence suggests that this variability is due to distinct pathophysiological mechanisms, which has led to an exhaustive research effort to understand and characterize these distinct entities currently designated as "endotypes." Initially, studies focused on identifying specific groups using clinical variables yielding different "clinical phenotypes." In addition, the identification of specific patterns based on inflammatory cell counts and cytokine data has resulted in "inflammatory endotypes." More recently, an increasing number of molecular data from high-throughput technology ("omics" data) have allowed to investigate more complex "molecular endotypes."

CONCLUSION

A better definition and comprehension of childhood asthma heterogeneity is key for improving diagnosis and treatment. This review aims at summarizing the current knowledge on this topic and discusses some limitations in their application as well as recommendations for future studies.

Prenatal polycyclic aromatic hydrocarbon exposure and asthma at age 8-9 years in a multi-site longitudinal study

Background and aim

Studies suggest prenatal exposure to polycyclic aromatic hydrocarbons (PAHs) may influence wheezing or asthma in preschool-aged children. However, the impact of prenatal PAH exposure on asthma and wheeze in middle childhood remain unclear. We investigated these associations in diverse participants from the ECHO PATHWAYS multi-cohort consortium.

Methods

We included 1,081 birth parent-child dyads across five U.S. cities. Maternal urinary mono-hydroxylated PAH metabolite concentrations (OH-PAH) were measured during mid-pregnancy. Asthma at age 8-9 years and wheezing trajectory across childhood were characterized by caregiver reported asthma diagnosis and asthma/wheeze symptoms. We used logistic and multinomial regression to estimate odds ratios of asthma and childhood wheezing trajectories associated with five individual OH-PAHs, adjusting for urine specific gravity, various maternal and child characteristics, study site, prenatal and postnatal smoke exposure, and birth year and season in single metabolite and mutually adjusted models. We used multiplicative interaction terms to evaluate effect modification by child sex and explored OH-PAH mixture effects through Weighted Quantile Sum regression.

Results

The prevalence of asthma in the study population was 10%. We found limited evidence of adverse associations between pregnancy OH-PAH concentrations and asthma or wheezing trajectories. We observed adverse associations between 1/9-hydroxyphenanthrene and asthma and persistent wheeze among girls, and evidence of inverse associations with asthma for 1-hydroxynathpthalene, which was stronger among boys, though tests for effect modification by child sex were not statistically.

Conclusions

In a large, multi-site cohort, we did not find strong evidence of an association between prenatal exposure to PAHs and child asthma at age 8-9 years, though some adverse associations were observed among girls.

Patterns of aeroallergen sensitization in asthma patients identified by latent class analysis: A cross-sectional study in China

BACKGROUND

This cross-sectional study aimed to identify latent sensitization profiles of asthma patients in mainland China, unveiling the association between regional differences and sensitization patterns.

METHODS

1056 asthma participants from 10 medical centers divided into eastern and western cohorts were clustered into four individual sensitization patterns, respectively, by using an unsupervised statistical modeling method, latent class analysis (LCA), based on the levels of 12 aeroallergens specific IgE reactivities. Moreover, differences in clinical characteristics and environmental exposures were compared in different sensitization patterns.

RESULTS

Four distinct sensitization patterns in the two cohorts were defined as follows, respectively. Eastern cohort: Class 1: "High weed pollen and house dust mites (HDMs) sensitization" (8.87%), Class 2: "HDMs dominated sensitization" (38.38%), Class 3: "High HDMs and animal dander sensitization" (6.95%), Class 4: "Low/no aeroallergen sensitization" (45.80%). Western cohort: Class 1: "High weed pollen sensitization" (26.14%), Class 2: "High multi-pollen sensitization" (15.02%), Class 3: "HDMs-dominated sensitization" (10.33%), Class 4: "Low/no aeroallergen sensitization" (48.51%). Of note, the significant statistical difference in age, asthma control test score (ACT) and comorbidities were observed within or between different sensitization patterns. Exposure factors in different sensitization patterns were pointed out.

CONCLUSIONS

Asthmatic patients with distinct sensitization patterns were clustered and identified through the LCA method, disclosing the relationship between sensitization profiles of multiple aeroallergens and geographical differences, providing novel insights and potential strategies for atopic disease monitoring, management and prevention in clinical practice.

Bronchial Remodeling-based Latent Class Analysis Predicts Exacerbations in Severe Preschool Wheezers

Rationale: Children with preschool wheezing represent a very heterogeneous population with wide variability regarding their clinical, inflammatory, obstructive, and/or remodeling patterns. We hypothesized that assessing bronchial remodeling would help clinicians to better characterize severe preschool wheezers. Objectives: The main objective was to identify bronchial remodeling-based latent classes of severe preschool wheezers. Secondary objectives were to compare cross-sectional and longitudinal clinical and biological data between classes and to assess the safety of bronchoscopy. Methods: This double-center prospective study (NCT02806466) included severe preschool wheezers (1-5 yr old) requiring fiberoptic bronchoscopy. Bronchial remodeling parameters (i.e., epithelial integrity, reticular basement membrane [RBM] thickness, mucus gland, fibrosis and bronchial smooth muscle [BSM] areas, the density of blood vessels, and RBM-BSM distance) were assessed and evaluated by latent class analysis. An independent cohort of severe preschool wheezers (NCT04558671) was used to validate our results. Measurements and Main Results: Fiberoptic bronchoscopy procedures were well tolerated. A two-class model was identified: Class BR1 was characterized by increased RBM thickness, normalized BSM area, the density of blood vessels, decreased mucus gland area, fibrosis, and RBM-BSM distance compared with Class BR2. No significant differences were found between classes in the year before fiberoptic bronchoscopy. By contrast, Class BR1 was associated with a shorter time to first exacerbation and an increased risk of both frequent (3 or more) and severe exacerbations during the year after bronchoscopy in the two cohorts. Conclusions: Assessing bronchial remodeling identified severe preschool wheezers at risk of frequent and severe subsequent exacerbations with a favorable benefit to risk ratio.

Asthma Management in Children

Asthma is a common, complex heterogeneous disease often beginning in early life and is characterized by reversible airflow obstruction. The phenotypic differences that exist in children with asthma may impact underlying comorbid conditions and pharmacologic treatment choices. Prenatal factors for increased risk of asthma could include maternal diet and the maternal microbiome. Evidence also suggests that postnatal microbial exposures and colonization contribute to the risk of allergic diseases and asthma. After confirming the diagnosis, asthma management in children centers on 3 broad areas: pharmacologic treatment, treatment of underlying comorbidities, and education of the patient and caregivers on the importance of adherence and device technique. Moreover, social determinants of health significantly impact on symptom burden and treatment response.

Parental occupational exposures prior to conception and offspring wheeze and eczema during first year of life

PURPOSE

Parental exposures prior to conception might influence asthma and allergy risk in offspring. As occupational exposures are established risk factors for asthma and allergies, we investigated if parental occupational exposures prior to conception cause wheeze and eczema in offspring during the first year of life.

METHODS

We analysed data of 436 families from an offspring cohort based on a follow-up study of German participants of the International Study of Asthma and Allergies in Childhood (ISAAC). Offspring cohort data was collected between 2009 and 2019. Occupational exposures were based on participants' work histories and measured by a Job-Exposure-Matrix. We used Bayesian logistic regression models for analysis. Inference and confounder selection were based on directed acyclic graphs.

RESULTS

In mothers, for both allergic and irritative occupational exposures prior to conception suggestive effects on offspring eczema during the first year of life were found (allergens: odds ratio (OR) 1.22, 95% compatibility interval (CI) 0.92-1.57; irritants: OR 1.36, 95% CI 0.99-1.77), while no relation with wheeze was suggested.

CONCLUSIONS

Our results suggest that reduction of asthma-related occupational exposures might not only reduce the burden of disease for occupationally induced or aggravated asthma and allergies in employees but also in their children.

The Italian severe/uncontrolled asthma registry (RItA): A 12-month clinical follow-up

BACKGROUND

follow-up studies on registries of severe/uncontrolled asthma (SUA) patients are scanty.

OBJECTIVE

to analyze baseline and follow-up characteristics of SUA patients and their longitudinal patterns.

METHODS

180 adult patients (age ≥15 yrs) were investigated at baseline and 12-month follow-up through the Italian SUA registry (RItA). Latent transition analysis (LTA) was performed to detect cross-sectional SUA phenotypes and longitudinal patterns. Risk factors for longitudinal patterns were assessed through logistic regression.

RESULTS

a significant/borderline improvement of asthma control outcomes in the last 2-4 weeks emerged at follow-up with respect to baseline for: daily activities limitations (Δ -16%), frequent diurnal symptoms (Δ -25%), uncontrolled asthma symptoms according to ACT (Δ -26%). Last 12-month use of oral corticosteroids was less frequent at follow-up than at baseline (Δ -25%). Health status improvement was confirmed by lung function test results. Through LTA, two longitudinal patterns were detected considering last 12-month control outcomes: "persistence/worsening" (53.9%), "under control/improvement" (46.1%). A lower likelihood of having "persistence/worsening" SUA was exhibited by patients under anti-IgE (OR 0.38, 95% CI 0.17-0.84) and inhaled corticosteroids-bronchodilator association treatment (OR 0.13, 95% CI 0.01-1.26, borderline value), while a higher likelihood was shown by older age at first asthma diagnosis (OR 1.04, 95% CI 1.01-1.07).

CONCLUSION

the implementation of a SUA registry, the availability of patient-level data and the application of an innovative longitudinal analysis allowed to observe a general improvement in asthma control, one year after baseline, and a lower risk of SUA "persistence/worsening" in patients under anti-IgE and regular ICS-bronchodilator association use.

Early-life residential exposure to moisture damage is associated with persistent wheezing in a Finnish birth cohort

BACKGROUND AND AIMS

Moisture damage increases the risk for respiratory disorders in childhood. Our aim was to determine whether early age residential exposure to inspector-observed moisture damage or mold is associated with different wheezing phenotypes later in childhood.

METHODS

Building inspections were performed by civil engineers, in a standardized manner, in the children's homes-mostly single family and row houses (N = 344)-in the first year of life. The children were followed up with repeated questionnaires until the age of 6 years and wheezing phenotypes-never/infrequent, transient, intermediate, late onset, and persistent-were defined using latent class analyses. The multinomial logistic regression model was used for statistical analysis.

RESULTS

A total of 63% (n = 218) had infrequent or no wheeze, 23% (n = 80) had transient and 9.6% (n = 21) had a persistent wheeze. Due to the low prevalence, results for intermediate (3.8%, n = 13) and late-onset wheeze (3.5%, n = 12) were not further evaluated. Most consistent associations were observed with the persistent wheeze phenotype with an adjusted odds ratio (95% confidence intervals) 2.04 (0.67-6.18) for minor moisture damage with or without mold spots (present in 23.8% of homes) and 3.68 (1.04-13.05) for major damage or any moisture damage with visible mold in a child's main living areas (present in 13.4% of homes). Early-age moisture damage or mold in the kitchen was associated with transient wheezing.

CONCLUSION

At an early age, residential exposure to moisture damage or mold, can be dose-dependently associated especially with persistent wheezing phenotype later in childhood.

Clinical Phenotypes and Mortality Biomarkers: A Study Focused on COVID-19 Patients with Neurological Diseases in Intensive Care Units

Purpose: To identify clinical phenotypes and biomarkers for best mortality prediction considering age, symptoms and comorbidities in COVID-19 patients with chronic neurological diseases in intensive care units (ICUs). Subjects and Methods: Data included 1252 COVID-19 patients admitted to ICUs in Cuba between January and August 2021. A k-means algorithm based on unsupervised learning was used to identify clinical patterns related to symptoms, comorbidities and age. The Stable Sparse Classifiers procedure (SSC) was employed for predicting mortality. The classification performance was assessed using the area under the receiver operating curve (AUC). Results: Six phenotypes using a modified v-fold cross validation for the k-means algorithm were identified: phenotype class 1, mean age 72.3 years (ys)-hypertension and coronary artery disease, alongside typical COVID-19 symptoms; class 2, mean age 63 ys-asthma, cough and fever; class 3, mean age 74.5 ys-hypertension, diabetes and cough; class 4, mean age 67.8 ys-hypertension and no symptoms; class 5, mean age 53 ys-cough and no comorbidities; class 6, mean age 60 ys-without symptoms or comorbidities. The chronic neurological disease (CND) percentage was distributed in the six phenotypes, predominantly in phenotypes of classes 3 (24.72%) and 4 (35,39%); χ² (5) 11.0129 p = 0.051134. The cerebrovascular disease was concentrated in classes 3 and 4; χ² (5) = 36.63, p = 0.000001. The mortality rate totaled 325 (25.79%), of which 56 (17.23%) had chronic neurological diseases. The highest in-hospital mortality rates were found in phenotypes 1 (37.22%) and 3 (33.98%). The SSC revealed that a neurological symptom (ageusia), together with two neurological diseases (cerebrovascular disease and Parkinson's disease), and in addition to ICU days, age and specific symptoms (fever, cough, dyspnea and chilliness) as well as particular comorbidities (hypertension, diabetes and asthma) indicated the best prediction performance (AUC = 0.67). Conclusions: The identification of clinical phenotypes and mortality biomarkers using practical variables and robust statistical methodologies make several noteworthy contributions to basic and experimental investigations for distinguishing the COVID-19 clinical spectrum and predicting mortality.

Anti-Inflammatory Effect of Ulinastatin on the Association Between Inflammatory Phenotypes in Acute Type A Aortic Dissection

Background

Acute type A aortic dissection (ATAAD) is a heterogeneous systemic inflammatory response syndrome. Identification of distinct inflammatory phenotypes may allow more precise therapy and improved care. We aim to investigate whether distinct inflammatory subphenotypes exist in ATAAD patients and respond differently to pharmacotherapies.

Methods

Retrospective analysis of data sets was conducted from the Additive Anti-inflammatory Actions for Aortopathy & Arteriopathy (5A) III study. Inflammatory subphenotypes were derived among 2008 ATAAD patients who received surgical repair at 11 Chinese hospitals (2016–2020) using latent class analysis applied to 14 laboratory signatures within 6 hours of hospital admission. Outcomes included operative mortality (Society of Thoracic Surgeons definition), derived subphenotype frequency, and the potential consequences of phenotype frequency distributions on the treatment effects.

Results

The median (interquartile range) age of patients was 54 (45–62) years, and 1423 (70.9%) were male. A two-class (two subphenotype) model was an improvement over a one-class model (P<·001), with 1451 (72.3%) patients in the hypoinflammatory subphenotype group and 557 (27.7%) in the hyperinflammatory subphenotype group. Patients with the hyperinflammatory subphenotype had higher operative mortality (71 [12.7%] vs 127 [8.8%]; P=0·007) than did those with the hypoinflammatory subphenotype. Furthermore, the interaction between ulinastatin treatment and subphenotype is not significant for operative mortality (P=0.15) but for ventilator time (P=0·04).

Conclusion

Two subphenotypes of ATAAD were identified in the 5A cohort that correlated with clinical outcomes, with significant interaction effect between anti-inflammatory treatment and subphenotypes for ventilator time, suggesting these phenotypes may help in understanding heterogeneity of treatment effects.

Trial Registration

Clinical Trials. Gov: number NCT04918108.

Modeling Wheezing Spells Identifies Phenotypes with Different Outcomes and Genetic Associates

Rationale: Longitudinal modeling of current wheezing identified similar phenotypes, but their characteristics often differ between studies. Objectives: We propose that a more comprehensive description of wheeze may better describe trajectories than binary information on the presence/absence of wheezing. Methods: We derived six multidimensional variables of wheezing spells from birth to adolescence (including duration, temporal sequencing, and the extent of persistence/recurrence). We applied partition-around-medoids clustering on these variables to derive phenotypes in five birth cohorts. We investigated within- and between-phenotype differences compared with binary latent class analysis models and ascertained associations of these phenotypes with asthma and lung function and with polymorphisms in asthma loci 17q12-21 and CDHR3 (cadherin-related family member 3). Measurements and Main Results: Analysis among 7,719 participants with complete data identified five spell-based wheeze phenotypes with a high degree of certainty: never (54.1%), early-transient (ETW) (23.7%), late-onset (LOW) (6.9%), persistent (PEW) (8.3%), and a novel phenotype, intermittent wheeze (INT) (6.9%). FEV₁/FVC was lower in PEW and INT compared with ETW and LOW and declined from age 8 years to adulthood in INT. 17q12-21 and CDHR3 polymorphisms were associated with higher odds of PEW and INT, but not ETW or LOW. Latent class analysis- and spell-based phenotypes appeared similar, but within-phenotype individual trajectories and phenotype allocation differed substantially. The spell-based approach was much more robust in dealing with missing data, and the derived clusters were more stable and internally homogeneous. Conclusions: Modeling of spell variables identified a novel intermittent wheeze phenotype associated with lung function decline to early adulthood. Using multidimensional spell variables may better capture wheeze development and provide a more robust input for phenotype derivation.

[Immune system and allergies-An unholy alliance]

Various factors affect the maturation of the infantile immune system both prenatally and postnatally, including risk and protective factors from the environment, nutrition, genetics and epigenetics. The microbiome seems to play a substantial role. The complex interaction and regulation of all these factors is ultimately decisive for whether a child develops an allergy during the course of development of the immune system. The genetic components play a decisive role in the development of allergic diseases. The epigenetic regulation could represent a mechanism where environmental influences act upon the immune regulation in the emergence of allergic diseases. The main factors in the pathophysiology of allergic reactions are a dysregulation of various cells of the innate and acquired immune systems as well as their interaction. This review describes the role of various T helper cell types in allergic diseases. The incidence and duration of airway infections are clearly increased in allergic patients compared to nonallergic controls. In addition to functional aspects, the reason for the more frequent infections is an impairment of the immune defence by the allergy-related persisting inflammation of the mucous membranes. These mechanisms must be differentiated from a true immunodeficiency. Allergic rhinitis (AR) and bronchial asthma are nowadays no longer defined as separate diseases but as two forms of expression of an atopic entity with a similar pathology. Both diseases can be mediated by immunoglobulin E and be elicited by identical triggers. A bronchial hyperreactivity is detectable in the majority of patients with AR but without clinical asthma.

New Directions in Understanding Atopic March Starting from Atopic Dermatitis

Recent evidence showed that the postulated linear progression of the atopic march, from atopic dermatitis to food and respiratory allergies, does not capture the heterogeneity of allergic phenotypes, which are influenced by complex interactions between environmental, genetic, and psychosocial factors. Indeed, multiple atopic trajectories are possible in addition to the classic atopic march. Nevertheless, atopic dermatitis is often the first manifestation of an atopic march. Improved understanding of atopic dermatitis pathogenesis is warranted as this could represent a turning point in the prevention of atopic march. In this review, we outline the recent findings on the pathogenetic mechanisms leading to atopic dermatitis that could be targeted by intervention strategies for the prevention of atopic march.

Long-Term Respiratory Consequences of Early-Life Respiratory Viral Infections: A Pragmatic Approach to Fundamental Questions

Early-life viral infection can have profound effects on the developing lung and immune systems, both important in asthma development. For decades, research has aimed to establish whether there is a causal link between these viral infections as an exposure and asthma later in childhood. Establishing causality will remain important, but new insights regarding early-life viral infection as an exposure, the recognition of asthma as a heterogeneous outcome, and the shared genetic susceptibility to both suggest a refocus from answering the theoretical question of causality toward additional pragmatic approaches focusing on improving patient outcomes across the spectrum of respiratory disease. This Clinical Commentary reviews the evidence on the consequences of early-life viral infection and aims to look beyond the question of causality, suggesting a research agenda specifically aimed at what matters for human development, and for the quality of life of current and future patients with wheezing disorders.

Emerging Roles of Non-Coding RNAs in Childhood Asthma

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

Immune Responsiveness to LPS Determines Risk of Childhood Wheeze and Asthma in 17q21 Risk Allele Carriers

BACKGROUND

In murine models microbial exposures induce protection from experimental allergic asthma through innate immunity. Our aim was to assess the association of early life innate immunity with the development of asthma in children at risk.

METHODS

In the PASTURE farm birth cohort innate, Th2, Th1 and Th17 cytokine expression at age 1 year was measured after stimulation of PBMCs with lipopolysaccharide (LPS) in N=445 children. Children at risk of asthma were defined based on single-nucleotide polymorphisms at the 17q21 asthma gene locus. Specifically, we used the SNP rs7216389 in the GSDMB gene. Wheeze in the 1st year of life was assessed by weekly diaries and asthma by questionnaire at age 6 years.

RESULTS

Not all cytokines were detectable in all children after LPS-stimulation. When classifying detectability of cytokines by latent class analysis, carrying the 17q21 risk allele rs7216389 was associated with risk of wheeze only in the class with the lowest level of LPS-induced activation, odds ratio (OR)=1.89, 95%-CI 1.13-3.16, p=0.015. In contrast, in children with high cytokine activation after LPS-stimulation no association of the 17q21 risk allele with wheeze (OR=0.63, 95%-CI 0.29-1.40, p=0.258, p=0.034 for interaction) or school age asthma was observed. In these children consumption of unprocessed cow's milk was associated with higher cytokine activation (OR=3.37, 95%-CI 1.56-7.30, p=0.002), which was in part mediated by the gut microbiome.

CONCLUSIONS

These findings suggest that within the 17q21 genotype asthma risk can be mitigated by activated immune responses after innate stimulation, which is partly mediated by a gut-immune axis.

Air pollution-related asthma profiles among children/adolescents: A multi-group latent class analysis

BACKGROUND

This study aimed to investigate the asthma profile among children/adolescents and the relationship of the prevalence of air pollution profiles using latent class analysis (LCA).

OBJECTIVES

In this cross-sectional study, a case rural community was selected in an industrial area, and two rural control communities were selected in unexposed areas.

METHODS

Hourly concentrations of PM₁₀, SO₂, NO_2, and total volatile organic compounds were obtained from the records of a fixed air quality monitoring station, and the concentrations of benzene, toluene, xylenes styrene were measured during six campaigns. Asthma data was collected using the International Study of Asthma and Allergies in Childhood in 7-18 years old children/adolescents. The modeling was conducted using LCA.

RESULTS

A higher amount of air pollution indices were observed in the case than both control communities. LCA divided the participants into three clusters; "healthy" (92.8%), "moderate" (2.8%), and "severe" (4.4%). A higher probability of severe asthma (6.8%) was observed in the case than control communities (2.6% and 1.8%). Additionally, after adjusting for possible confounders, the odds of asthma was lower in the control communities than the case in both moderate and sever classes (Odds Ratios in the range of 0.135-0.697).

CONCLUSIONS

This study indicates asthma profiles of children/adolescents and the higher prevalence of severe class in the area, explaining the possible effect of air pollution.

Prenatal and perinatal home environment and reported onset of wheeze, rhinitis and eczema symptoms in preschool children in Northern China

Early life environment can affect asthma and allergies but few cohort studies on this issue are available from China. Our aim was to investigate reported onset of childhood wheeze, rhinitis and eczema symptoms in relation to prenatal, perinatal and postnatal home environment. Data on home environment and symptoms (ISAAC based questions) in first two years of life and in the past 12 months were reported by parents of the children (3-6 y) in a cross-sectional questionnaire survey in ten day care centers in Taiyuan, northern China (N = 3606). Changes of symptoms from the first 2 years of life to the past 12 months (recall period) were calculated retrospectively. Multilevel logistic regression analysis was applied. Reported onset of wheeze, rhinitis and eczema were 11.8%, 22.2% and 3.3%, respectively. Redecorating during pregnancy increased reported onset of rhinitis (OR = 2.29) and eczema (OR = 4.91). New furniture during pregnancy increased reported onset of rhinitis (OR = 1.47). Perinatal indoor mould increased reported onset of wheeze (OR = 1.51), rhinitis (OR = 1.65) and eczema (OR = 1.91). Perinatal mould odour increased reported onset of wheeze (OR = 1.85). Perinatal window pane condensation increased reported onset of wheeze (OR = 1.54) and rhinitis (OR = 1.24). Perinatal stuffy air and dry air in the home increased reported onset of all three symptoms (ORs 1.46-2.24). Dog keeping increased reported onset of wheeze (OR = 1.69) and eczema (OR = 2.13). Based on principal component analysis, four exposure scores were calculated (renovation, new furniture, mould and indoor air quality scores). Dose-response relationships were observed between these exposure scores and reported onset of symptoms. In conclusion, prenatal and postnatal exposure to emissions from renovation and new furniture can increase reported onset of childhood wheeze, rhinitis and eczema. Perinatal indoor mould, mould odour, condensation on window panes and impaired indoor air quality at home can be associated with reported development of wheeze, rhinitis and eczema in preschoolers in northern China.

The role of innate immunity in asthma development and protection: Lessons from the environment

Asthma, a complex, chronic disease characterized by airway inflammation, hyperresponsiveness and remodelling, affects over 300 million people worldwide. While the disease is typically associated with exaggerated allergen-induced type 2 immune responses, these responses are strongly influenced by environmental exposures that stimulate innate immune pathways capable of promoting or protecting from asthma. The dual role played by innate immunity in asthma pathogenesis offers multiple opportunities for both research and clinical interventions and is the subject of this review.

Excessive Unbalanced Meat Consumption in the First Year of Life Increases Asthma Risk in the PASTURE and LUKAS2 Birth Cohorts

A higher diversity of food items introduced in the first year of life has been inversely related to subsequent development of asthma. In the current analysis, we applied latent class analysis (LCA) to systematically assess feeding patterns and to relate them to asthma risk at school age. PASTURE (N=1133) and LUKAS2 (N=228) are prospective birth cohort studies designed to evaluate protective and risk factors for atopic diseases, including dietary patterns. Feeding practices were reported by parents in monthly diaries between the 4^th and 12^th month of life. For 17 common food items parents indicated frequency of feeding during the last 4 weeks in 4 categories. The resulting 153 ordinal variables were entered in a LCA. The intestinal microbiome was assessed at the age of 12 months by 16S rRNA sequencing. Data on feeding practice with at least one reported time point was available in 1042 of the 1133 recruited children. Best LCA model fit was achieved by the 4-class solution. One class showed an elevated risk of asthma at age 6 as compared to the other classes (adjusted odds ratio (aOR): 8.47, 95% CI 2.52–28.56, p = 0.001) and was characterized by daily meat consumption and rare consumption of milk and yoghurt. A refined LCA restricted to meat, milk, and yoghurt confirmed the asthma risk effect of a particular class in PASTURE and independently in LUKAS2, which we thus termed unbalanced meat consumption (UMC). The effect of UMC was particularly strong for non-atopic asthma and asthma irrespectively of early bronchitis (aOR: 17.0, 95% CI 5.2–56.1, p < 0.001). UMC fostered growth of iron scavenging bacteria such as Acinetobacter (aOR: 1.28, 95% CI 1.00-1.63, p = 0.048), which was also related to asthma (aOR: 1.55, 95% CI 1.18-2.03, p = 0.001). When reconstructing bacterial metabolic pathways from 16S rRNA sequencing data, biosynthesis of siderophore group nonribosomal peptides emerged as top hit (aOR: 1.58, 95% CI 1.13-2.19, p = 0.007). By a data-driven approach we found a pattern of overly meat consumption at the expense of other protein sources to confer risk of asthma. Microbiome analysis of fecal samples pointed towards overgrowth of iron-dependent bacteria and bacterial iron metabolism as a potential explanation.

Predicting Severe Asthma Exacerbations in Children: Blueprint for Today and Tomorrow

Severe asthma exacerbations are the primary cause of morbidity and mortality in children with asthma. Accurate prediction of children at risk for severe exacerbations, defined as those requiring systemic corticosteroids, emergency department visit, and/or hospitalization, would considerably reduce health care utilization and improve symptoms and quality of life. Substantial progress has been made in identifying high-risk exacerbation-prone children. Known risk factors for exacerbations include demographic characteristics (ie, low income, minority race/ethnicity), poor asthma control, environmental exposures (ie, aeroallergen exposure/sensitization, concomitant viral infection), inflammatory biomarkers, genetic polymorphisms, and markers from other "omic" technologies. The strongest risk factor for a future severe exacerbation remains having had one in the previous year. Combining risk factors into composite scores and use of advanced predictive analytic techniques such as machine learning are recent methods used to achieve stronger prediction of severe exacerbations. However, these methods are limited in prediction efficiency and are currently unable to predict children at risk for impending (within days) severe exacerbations. Thus, we provide a commentary on strategies that have potential to allow for accurate and reliable prediction of children at risk for impending exacerbations. These approaches include implementation of passive, real-time monitoring of impending exacerbation predictors, use of population health strategies, prediction of severe exacerbation responders versus nonresponders to conventional exacerbation management, and considerations for preschool-age children who can be especially high risk. Rigorous prediction and prevention of severe asthma exacerbations is needed to advance asthma management and improve the associated morbidity and mortality.

The Hygiene Hypothesis and New Perspectives-Current Challenges Meeting an Old Postulate

During its 30 years history, the Hygiene Hypothesis has shown itself to be adaptable whenever it has been challenged by new scientific developments and this is a still a continuously ongoing process. In this regard, the mini review aims to discuss some selected new developments in relation to their impact on further fine-tuning and expansion of the Hygiene Hypothesis. This will include the role of recently discovered classes of innate and adaptive immune cells that challenges the old Th1/Th2 paradigm, the applicability of the Hygiene Hypothesis to newly identified allergy/asthma phenotypes with diverse underlying pathomechanistic endotypes, and the increasing knowledge derived from epigenetic studies that leads to better understanding of mechanisms involved in the translation of environmental impacts on biological systems. Further, we discuss in brief the expansion of the Hygiene Hypothesis to other disease areas like psychiatric disorders and cancer and conclude that the continuously developing Hygiene Hypothesis may provide a more generalized explanation for health burden in highly industrialized countries also relation to global changes.

Phenotypes and Subphenotypes of Patients With COVID-19: A Latent Class Modeling Analysis

Background

Since COVID-19 was identified, its clinical and biological heterogeneity has been recognized. Identifying COVID-19 phenotypes might help guide basic, clinical, and translational research efforts.

Research Question

Does the clinical spectrum of patients with COVID-19 contain distinct phenotypes and subphenotypes?

Study Design and Methods

We included adult patients (≥ 18 years) positive for laboratory-confirmed SARS-CoV-2 infection from a prospective COVID-19 registry database in the Cleveland Clinic Health System in Ohio and Florida. The patients were split into training and testing sets. Using latent class analysis (LCA), we first identified phenotypic clusters of patients with COVID-19 based on demographics, comorbidities, and presenting symptoms. We then identified subphenotypes of hospitalized patients with additional blood biomarker data measured on hospital admission. The associations of phenotypes/subphenotypes and clinical outcomes were investigated. Multivariable prediction models were established to predict assignment to the LCA-defined phenotypes and subphenotypes and then evaluated on an independent testing set.

Results

We analyzed data for 20,572 patients. Seven phenotypes were identified on the basis of different profiles of presenting COVID-19 symptoms and existing comorbidities, including the following groups: young, no symptoms; young, symptoms; middle-aged, no symptoms; middle-aged, symptoms; middle-aged, comorbidities; old, no symptoms; and old, symptoms. The rates of inpatient hospitalization for the phenotypes were significantly different (P < .001). Five subphenotypes were identified for the subgroup of hospitalized patients, including the following subgroups: young, elevated WBC and platelet counts; middle-aged, lymphopenic with elevated C-reactive protein; middle-aged, hyperinflammatory; old, leukopenic with comorbidities; and old, hyperinflammatory with kidney dysfunction. The hospital mortality and the times from hospitalization to ICU transfer or death were significantly different (P < .001). The models for predicting the LCA-defined phenotypes and subphenotypes showed high discrimination (concordance index, 0.92 and 0.91).

Interpretation

Hypothesis-free LCA-defined phenotypes and subphenotypes of patients with COVID-19 can be identified. These may help clinical investigators conduct stratified analyses in clinical trials and assist basic science researchers in characterizing the pathobiology of the spectrum of COVID-19 presentations.

Maturation of the gut microbiome during the first year of life contributes to the protective farm effect on childhood asthma

Growing up on a farm is associated with an asthma-protective effect, but the mechanisms underlying this effect are largely unknown. In the Protection against Allergy: Study in Rural Environments (PASTURE) birth cohort, we modeled maturation using 16S rRNA sequence data of the human gut microbiome in infants from 2 to 12 months of age. The estimated microbiome age (EMA) in 12-month-old infants was associated with previous farm exposure (β = 0.27 (0.12-0.43), P = 0.001, n = 618) and reduced risk of asthma at school age (odds ratio (OR) = 0.72 (0.56-0.93), P = 0.011). EMA mediated the protective farm effect by 19%. In a nested case-control sample (n = 138), we found inverse associations of asthma with the measured level of fecal butyrate (OR = 0.28 (0.09-0.91), P = 0.034), bacterial taxa that predict butyrate production (OR = 0.38 (0.17-0.84), P = 0.017) and the relative abundance of the gene encoding butyryl-coenzyme A (CoA):acetate-CoA-transferase, a major enzyme in butyrate metabolism (OR = 0.43 (0.19-0.97), P = 0.042). The gut microbiome may contribute to asthma protection through metabolites, supporting the concept of a gut-lung axis in humans.

Identification of bronchiolitis profiles in Italian children through the application of latent class analysis

BACKGROUND

Bronchiolitis is the primary infection of the lower respiratory tract in children under 2 years of age. Although it is generally considered a single nosological entity, recent studies suggested remarkable clinical heterogeneity. To date, no studies have identified classes of children with bronchiolitis within the Italian population. This study aimed to identify discrete profiles of Italian children hospitalized with bronchiolitis using a clustering approach and to compare findings with those obtained in international cohorts.

METHODS

This was a retrospective single-centre study conducted on children aged ≤2 years hospitalised with bronchiolitis (n = 401) at the Department of Infectious Diseases and the University Department of General Pediatrics in "Giovanni Di Cristina" Pediatric Hospital of Palermo, Italy, between November 2012 and May 2019. Bronchiolitis profiles were determined by latent class analysis, classifying children based on clinical characteristics at admission and viral aetiology.

RESULTS

Three profiles were identified. Class 1 (49%) was composed of 45% male children; all children were aged ≤6 months at hospitalization; 77% were infected with RSV; 100% had respiratory distress, 11% had apnea and none had cough. Class 2 (77%) was mainly composed of male subjects (51%); 19% were aged > 6 months at admission; 37% were infected with RSV; 12% had respiratory distress, 5% had apnea and 90% had cough. Class 3 (19%) included the largest proportion of male subjects (94%) and was mostly composed of children aged > 6 months at the time of admission (68%); 70% had cough, 12% showed respiratory distress and none presented with apnoea. Children in Class 1 were more frequently born near the epidemic season (p = 0.028); breastfeeding duration was significantly longer for children in Class 3 (p = 0.004).

CONCLUSIONS

The study identified distinct clinical profiles of bronchiolitis by a clustering approach in a single-centre study of children hospitalised for bronchiolitis in Italy. The three bronchiolitis profiles share some similarities with those identified in international studies using the same statistical approach. These findings may help to increase the understanding of the phenotypic variability that typically characterizes bronchiolitis, with relevant implications for future research.

Distinguishing Wheezing Phenotypes from Infancy to Adolescence. A Pooled Analysis of Five Birth Cohorts

Rationale: Pooling data from multiple cohorts and extending the time frame across childhood should minimize study-specific effects, enabling better characterization of childhood wheezing.

Objectives: To analyze wheezing patterns from early childhood to adolescence using combined data from five birth cohorts.

Methods: We used latent class analysis to derive wheeze phenotypes among 7,719 participants from five birth cohorts with complete report of wheeze at five time periods. We tested the associations of derived phenotypes with late asthma outcomes and lung function, and investigated the uncertainty in phenotype assignment.

Results: We identified five phenotypes: never/infrequent wheeze (52.1%), early onset preschool remitting (23.9%), early onset midchildhood remitting (9%), persistent (7.9%), and late-onset wheeze (7.1%). Compared with the never/infrequent wheeze, all phenotypes had higher odds of asthma and lower forced expiratory volume in 1 second and forced expiratory volume in 1 second/forced vital capacity in adolescence. The association with asthma was strongest for persistent wheeze (adjusted odds ratio, 56.54; 95% confidence interval, 43.75–73.06). We observed considerable within-class heterogeneity at the individual level, with 913 (12%) children having low membership probability (<0.60) of any phenotype. Class membership certainty was highest in persistent and never/infrequent, and lowest in late-onset wheeze (with 51% of participants having membership probabilities <0.80). Individual wheezing patterns were particularly heterogeneous in late-onset wheeze, whereas many children assigned to early onset preschool remitting class reported wheezing at later time points.

Conclusions: All wheeze phenotypes had significantly diminished lung function in school-age children, suggesting that the notion that early life episodic wheeze has a benign prognosis may not be true for a proportion of transient wheezers. We observed considerable within-phenotype heterogeneity in individual wheezing patterns.

Addressing the risk domain in the long-term management of pediatric asthma

There is growing concern regarding the long-term outcomes of early and poorly controlled childhood asthma, either of which can potentially lead to the development of severe asthma in adults and irrecoverable loss of lung function leading to chronic obstructive pulmonary disease. These outcomes of inadequately controlled asthma should prompt a change in practice to better and/or earlier identify children at risk of adverse respiratory outcomes of asthma, to monitor disease progression, and to design intervention strategies that could either prevent or reverse asthma progression in children. The careful follow-up of spirometry over time-in the form of lung function trajectories, the application of biomarkers to assist in the diagnosis of early asthma and medication selection for these patients, as well as methods to identify patients at risk of asthma attacks-can be used to develop individualized management strategies for children with asthma. It is now time for asthma specialists to communicate this information to patients, parents, and primary care physicians and to incorporate them into routine clinical assessments of children with asthma. In time, these concepts of risk management and prevention can be refined to provide a more comprehensive approach to asthma care so as to prevent adverse respiratory outcomes from poorly controlled childhood asthma.

Hypersensitivity Reactions: An Everyday Occurrence in Pediatric Allergy Clinics

The explanation of hypersensitivity reactions has long relied on the classification of Gell and Coombs, originally proposed in the 1960s. However, their concepts were predated by other authors by at least 50 years. A 21st century pediatric allergy clinic provides multiple examples of these basic concepts on a daily basis. We review classic and less classic examples of the original criteria, highlight where current disease pathophysiology does not always fit the original model, and provide updated language for common and uncommon immunologically driven hypersensitivity diseases.

Do Current Asthma-Preventive Measures Appropriately Face the World Health Organization's Concerns: A Study Presentation of a New Clinical, Prospective, Multicentric Pediatric Asthma Exacerbation Cohort in Germany

In summer 2017, the World Health Organization published 10 facts on asthma, which is known as a major non-communicable disease of high clinical and scientific importance with currently several hundred million people-with many children among them-suffering from air passages inflammation and narrowing. Importantly, the World Health Organization sees asthma as being underdiagnosed and undertreated. Consequently, much more efforts in clinical disease management and research need to be spent on reducing the asthma-related health burden. Particularly, for young approximately 6 months aged patients presenting recurrent bronchitic respiratory symptoms, many parents anxiously ask the doctors for risk prognosis for their children's future life. Therefore, we urgently need to reevaluate if the current diagnostic and treatment measures are in concordance with our yet incomplete knowledge of pathomechanisms on exacerbation. To contribute to this increasing concern worldwide, we established a multicentric pediatric exacerbation study network, still recruiting acute exacerbated asthmatics (children >6 years) and preschool asthmatics/wheezers (children <6 years) since winter 2018 in Germany. The current study that has a currently population comprising 176 study participants aims to discover novel holistic entry points for achieving a better understanding of the poorly understood plasticity of involved molecular pathways and to define biomarkers enabling improved diagnostics and therapeutics. With this study description, we want to present the study design, population, and few ongoing experiments for novel biomarker research. Clinical Trial Registration: German Clinical Trials Register (Deutsches Register für Klinische Studien, DRKS): DRKS00015738.

A modern approach to identifying and characterizing child asthma and wheeze phenotypes based on clinical data

‘Asthma’ is a complex disease that encapsulates a heterogeneous group of phenotypes and endotypes. Research to understand these phenotypes has previously been based on longitudinal wheeze patterns or hypothesis-driven observational criteria. The aim of this study was to use data-driven machine learning to identify asthma and wheeze phenotypes in children based on symptom and symptom history data, and, to further characterize these phenotypes. The study population included an asthma-rich population of twins in Sweden aged 9–15 years (n = 752). Latent class analysis using current and historical clinical symptom data generated asthma and wheeze phenotypes. Characterization was then performed with regression analyses using diagnostic data: lung function and immunological biomarkers, parent-reported medication use and risk-factors. The latent class analysis identified four asthma/wheeze phenotypes: early transient wheeze (15%); current wheeze/asthma (5%); mild asthma (9%), moderate asthma (10%) and a healthy phenotype (61%). All wheeze and asthma phenotypes were associated with reduced lung function and risk of hayfever compared to healthy. Children with mild and moderate asthma phenotypes were also more likely to have eczema, allergic sensitization and a family history of asthma. Furthermore, those with moderate asthma phenotype had a higher eosinophil concentration (β 0.21, 95%CI 0.12, 0.30) compared to healthy and used short-term relievers at a higher rate than children with mild asthma phenotype (RR 2.4, 95%CI 1.2–4.9). In conclusion, using a data driven approach we identified four wheeze/asthma phenotypes which were validated with further characterization as unique from one another and which can be adapted for use by the clinician or researcher.

Parents know it best: Prediction of asthma and lung function by parental perception of early wheezing episodes

BACKGROUND

Childhood asthma is often preceded by early wheeze. Usually, wheezing episodes are recorded retrospectively, which may induce recall bias.

AIMS AND OBJECTIVES

The aim of this study was to investigate true-positive recall of parent-reported wheeze at 1 year of age, its determinants, and its implications for asthma and lung function at 6 years of age.

METHODS

The PASTURE (Protection Against Allergy-Study in Rural Environments) study followed 880 children from rural areas in 5 European countries from birth to age 6 years. Wheeze symptoms in the first year were asked weekly. At age 6, parent-reported asthma diagnosis was ascertained and lung function measurements were conducted. Correct parental recall of wheeze episodes at the end of the first year was assessed for associations with lung function, asthma, and the asthma risk locus on chromosome 17q21.

RESULTS

Parents correctly recalled wheeze after the first year in 54% of wheezers. This true-positive recall was determined by number of episodes, timing of the last wheeze episode, and parental asthma. Independently from these determinants, true-positive recall predicted asthma at age 6 years (odds ratio 4.54, 95% confidence interval (CI) [1.75-14.16]) and impaired lung function (β = -0.62, 95% CI [-1.12; -0.13], P-value = .02). Associations were stronger in children with asthma risk SNPs on chromosome 17q21.

CONCLUSION

Correct parental recall of wheezing episodes may reflect clinical relevance of early wheeze and its impact on subsequent asthma and lung function impairment. Questions tailored to parental perception of wheezing episodes may further enhance asthma prediction.

Development and validation of exhaled breath condensate microRNAs to identify and endotype asthma in children

Detection and quantification of microRNAs (miRNAs) in exhaled breath condensate (EBC) has been poorly explored. Therefore we aimed to assess miRNAs in EBC as potential biomarkers to diagnose and endotype asthma in school aged children. In a cross sectional, nested case control study, all the asthmatic children (n = 71) and a random sample of controls (n = 115), aged 7 to 12 years, attending 71 classrooms from 20 local schools were selected and arbitrarily allocated to the development or validation set. Participants underwent skin-prick testing, spirometry with bronchodilation, had exhaled level of nitric oxide determined and EBC collected. Based on previous studies eleven miRNAs were chosen and analyzed in EBC by reverse transcription-quantitative real-time PCR. Principal component analysis was applied to identify miRNAs profiles and associations were estimated using regression models. In the development set (n = 89) two clusters of miRNAs were identified. After adjustments, cluster 1 and three of its clustered miRNAs, miR-126-3p, miR-133a-3p and miR-145-5p were positively associated with asthma. Moreover miR-21-5p was negatively associated with symptomatic asthma and positively associated with positive bronchodilation without symptoms. An association was also found between miR-126-3p, cluster 2 and one of its clustered miRNA, miR-146-5p, with higher FEF25-75 reversibility. These findings were confirmed in the validation set (n = 97) where two identical clusters of miRNAs were identified. Additional significant associations were observed between miR-155-5p with symptomatic asthma, negative bronchodilation with symptoms and positive bronchodilation without symptoms. We showed that microRNAs can be measured in EBC of children and may be used as potential biomarkers of asthma, assisting asthma endotype establishment.

Disease trajectories in childhood atopic dermatitis: an update and practitioner's guide

BACKGROUND

Atopic dermatitis (AD) is a heterogeneous disease with a multifactorial aetiology and complex pathophysiology. This heterogeneity translates into different trajectories of disease progression with respect to severity, persistence and risk of development of atopic comorbidities. Determining which possible disease trajectories or comorbidities any individual child might develop is challenging in clinical practice. Tools that help identify paediatric patients at higher risk of disease progression would greatly aid clinicians.

METHODS

We reviewed recent cohort studies to synthesize and simplify the epidemiological data to try to identify shared clinically relevant characteristics that may help physicians estimate the risk of disease progression in paediatric patients with AD.

RESULTS

Despite the variability in data collection and methods of analysis and their limitations, there are common patterns of early-childhood AD that may aid in the estimation of risk for disease progression. Factors associated with risk of AD progression include younger age of onset, family history of atopy, greater AD severity, filaggrin mutations, urban environment and polysensitization and/or allergic multimorbidity. Based on these factors, we provide a practitioner's guide for identifying, counselling and/or referring infants and children with AD at potentially higher risk of developing persistent AD and atopic comorbidities. We also present clinical scenarios to illustrate how these data relate to real-life situations.

CONCLUSIONS

Useful insights are provided for physicians and patients to inform them better about the risk of AD progression and to help guide care pathways for the paediatric population with AD. What's already known about this topic? The complex pathophysiology of atopic dermatitis (AD) translates into a heterogeneous clinical presentation and trajectories of disease progression. Although the consensus is that most paediatric patients with AD will eventually 'outgrow' the disease or follow the longitudinal trajectory known as the 'atopic march', a significant proportion will develop persistent AD and/or other atopic conditions. No known factors conclusively predict the risk of progression or development of comorbidities. What does this study add? Recent analyses of data from large cohorts of paediatric patients with AD have suggested the existence of potentially discrete clusters of patients who present with relatively common AD phenotypes. These studies have shed some light onto the factors associated with risk of progression, which we review in this article. A practitioner's guide with clinical scenarios is provided to help identify patients at high risk of progression to determine whether a patient should be monitored and/or would require specialist referral.

TNF-α-induced protein 3 is a key player in childhood asthma development and environment-mediated protection

BACKGROUND

Childhood asthma prevalence is significantly greater in urban areas compared with rural/farm environments. Murine studies have shown that TNF-α-induced protein 3 (TNFAIP3; A20), an anti-inflammatory regulator of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling, mediates environmentally induced asthma protection.

OBJECTIVE

We aimed to determine the role of TNFAIP3 for asthma development in childhood and the immunomodulatory effects of environmental factors.

METHODS

In a representative selection of 250 of 2168 children from 2 prospective birth cohorts and 2 cross-sectional studies, we analyzed blood cells of healthy and asthmatic children from urban and rural/farm environments from Europe and China. PBMCs were stimulated ex vivo with dust from "asthma-protective" farms or LPS. NF-κB signaling-related gene and protein expression was assessed in PBMCs and multiplex gene expression assays (NanoString Technologies) in isolated dendritic cells of schoolchildren and in cord blood mononuclear cells from newborns.

RESULTS

Anti-inflammatory TNFAIP3 gene and protein expression was consistently decreased, whereas proinflammatory Toll-like receptor 4 expression was increased in urban asthmatic patients (P < .05), reflecting their increased inflammatory status. Ex vivo farm dust or LPS stimulation restored TNFAIP3 expression to healthy levels in asthmatic patients and shifted NF-κB signaling-associated gene expression toward an anti-inflammatory state (P < .001). Farm/rural children had lower expression, indicating tolerance induction by continuous environmental exposure. Newborns with asthma at school age had reduced TNFAIP3 expression at birth, suggesting TNFAIP3 as a possible biomarker predicting subsequent asthma.

CONCLUSION

Our data indicate TNFAIP3 as a key regulator during childhood asthma development and its environmentally mediated protection. Because environmental dust exposure conferred the anti-inflammatory effects, it might represent a promising future agent for asthma prevention and treatment.

Transition for Adolescents and Young Adults With Asthma

Asthma is a complex, heterogenous medical condition which is very common in children and adults. The transition process from pediatric to adult health care services can be a challenge for young people with chronic medical conditions. The significant changes in physical and mental health during this time, as well as the many unique developmental and psychosocial challenges that occur during adolescence can complicate and impede transition if not adequately addressed and managed. The transition period can also be a challenging time for health professionals to assess readiness for transition and manage some of the complications which are particularly common during this time, including poor adherence to therapy, smoking, drug use, and emerging mental health conditions. The natural history, presentation, symptoms, and management of asthma is often significantly different when comparing pediatric and adult practice. In addition, management in infants, toddlers, school aged children, and adolescents differs significantly, offering an additional challenge to pediatric physicians managing asthmatic children and young people. Despite these challenges, if the transition process for young people with asthma is planned and performed in a formalized manner, many of these issues can be addressed, allowing the transition to occur smoothly despite changes that may occur in medical and psychosocial domains.

[Reasons for the development of allergies in children]

Allergies are one of the most common chronic diseases in childhood, contributing to a tremendous medical and economical burden in health care systems of most industrialized countries. The development of allergies is dependent on a complex interaction of-among others-environmental factors, nutrition, genetic and epigenetic mechanisms as well as the microbiome. These diverse factors can influence early life immune regulation including innate and adaptive immune mechanisms in a complex fashion. In case of any Childhood allergies have increased significantly in past decades. In addition to environmental factors and nutrition, genetic and epigenetic mechanisms as well as the microbiome of children play an important role. Of relevance is the way in which these diverse factors influence early immune development of the innate and adaptive immune systems of children. Their complex regulation is decisive for whether or not a child develops an allergy that manifests in most cases as atopic dermatitis, bronchial asthma, or allergic rhino conjunctivitis, or whether a child develops an immune tolerance. These influences can begin prenatally, already setting the course for later immune system development and occurrence of disease.