Update in asthma 2012

Medical care and treatment of children with asthmatic or wheezing health outcomes and urban-rural differences in Bavaria - a cross-sectional study

Introduction: Asthma is among the most common chronic conditions in children. The aim of this publication is to describe prevalence rates and factors associated with asthmatic or wheezing preschoolers and to evaluate medical care and treatment with regard to urban-rural differences.Methods: Data for this cross-sectional study were collected through a questionnaire, which was distributed to parents within the Health Monitoring Units in Bavaria (HMU), Germany. Data from 4767 children were available (2016/17). Those children were classified into four diagnostic groups: Unremitting Wheeze, International Study of Asthma and Allergies in Children (ISAAC) Asthma, Physician-diagnosed Asthma, and healthy control group. Urban-rural differences were tested by Pearson's chi-squared test or by Fisher's exact test. Independent variables were factors associated with health outcomes, for example, residency or migrant status. To examine associations between independent and outcome variables multivariate logistic regression analysis was performed.Results: Prevalence rates were 6.3% for 'Unremitting Wheeze', 5.2% for 'ISAAC Asthma', and 1.2% for 'Physician-diagnosed Asthma'. Factors associated with health outcomes were the occurrence of asthma in first-degree relatives, male sex, and migrant status. Generally, higher rates of doctor's visits, positive allergy tests, and corticosteroids intake in the diagnostic groups in rural compared to urban areas were observed. Rates of performed allergy tests were 55.6% for 'ISAAC Asthma' and 74.6% for 'Physician-diagnosed Asthma'.Conclusions: Prevalence rates of the diagnostic groups decreased compared to the HMU 2014/15. According to previous studies, factors associated with asthmatic or wheezing health outcomes could be confirmed. Children in rural areas generally received more medical care.Key pointsChildren's prevalence rates of asthma or wheezing disorders decreased in the past 2 years within Bavaria.This study is consistent with risk factors for asthma from the literature: asthma in the family, male gender, and migrant status.Children in rural areas receive more medical care than children in urban areas.There should me more allergy tests among children with medical diagnosis in Bavaria as low rates indicate gaps in care.

Genetic association of ADAM33 polymorphisms with childhood asthma in Chinese Han population: A case-control study

To explore the association of a disintegrin and metalloprotease 33 (ADAM33) polymorphisms with childhood asthma susceptibility, we conducted this case-control study.In this case-control study, we selected 96 asthma children and 86 healthy children to conduct the genotyping of ADAM33 polymorphisms through polymerase chain reaction-direct sequencing (PCR-DS). Hardy-Weinberg equilibrium (HWE) status in the control group was detected adopting chi-square test. Frequency differences of genotypes, alleles, and haplotypes were compared by chi-square test between the case and control groups. Linkage disequilibrium (LD) between polymorphisms was checked using Haploview software. Association intensity of the polymorphisms with the disease risk was assessed by odds ratio (OR) and 95% confidence interval (95%CI).The frequency of rs678881 GA genotype was obviously higher in cases than in controls (P = .03) and the carriage of this genotype conferred higher risk of asthma among children than GG genotype (OR = 2.03, 95%CI = 1.05-3.91). However, neither rs2280089 nor rs2853209 polymorphism was significantly associated with the risk of childhood asthma. Strong LD was found among rs678881, rs2280089 and rs2853209, and haplotype GGT was distinctly associated with the risk of asthma in children (OR = 0.28, 95%CI = 0.13-0.57).ADAM33 rs678881 polymorphism is significantly correlated with increased susceptibility to asthma in Chinese Han children. Besides, haplotype GGT among the 3 polymorphisms was obviously associated with decreased risk of childhood asthma.

Genomic Predictors of Asthma Phenotypes and Treatment Response

Asthma is a complex respiratory disease considered as the most common chronic condition in children. A large genetic contribution to asthma susceptibility is predicted by the clustering of asthma and allergy symptoms among relatives and the large disease heritability estimated from twin studies, ranging from 55 to 90%. Genetic basis of asthma has been extensively investigated in the past 40 years using linkage analysis and candidate-gene association studies. However, the development of dense arrays for polymorphism genotyping has enabled the transition toward genome-wide association studies (GWAS), which have led the discovery of several unanticipated asthma genes in the last 11 years. Despite this, currently known risk variants identified using many thousand samples from distinct ethnicities only explain a small proportion of asthma heritability. This review examines the main findings of the last 2 years in genomic studies of asthma using GWAS and admixture mapping studies, as well as the direction of studies fostering integrative perspectives involving omics data. Additionally, we discuss the need for assessing the whole spectrum of genetic variation in association studies of asthma susceptibility, severity, and treatment response in order to further improve our knowledge of asthma genes and predictive biomarkers. Leveraging the individual's genetic information will allow a better understanding of asthma pathogenesis and will facilitate the transition toward a more precise diagnosis and treatment.

Early Folic Acid Supplement Initiation and Risk of Adverse Early Childhood Respiratory Health: A Population-based Study

Objectives Folate plays a vital role in biologic functions yet women often do not meet the recommended dietary intake in pregnancy. It has been suggested that high folic acid intake during pregnancy may increase the risk of respiratory diseases in offspring. However, findings from observational studies in human populations are inconclusive. Methods In this population-based study, we collected self-reported folic acid and prenatal vitamin supplement use during pregnancy 3-6 months postpartum from mothers in Los Angeles whose children were born in 2003. Supplement initiation was based on whichever supplement, either folic acid or prenatal supplements, the women initiated first. In a 2006 follow-up survey, approximately 50% of women were re-contacted to gather information on the child's respiratory health, including symptoms and diagnoses, at approximately 3.5 years of age. Results Overall, timing of folic acid supplement initiation was not associated with wheeze or lower respiratory tract infection, even after accounting for preterm births and censoring at follow-up. However, children born to mothers with a history of atopy (hay fever, eczema or asthma) who initiate folic acid supplements in late pregnancy, compared to first trimester initiators, have 1.67 (95% CI 1.12, 2.49) times the risk of wheeze in the first 3 years of life and 1.88 (95% CI 1.05, 3.34) times the risk of wheeze in the past year. No association was found among children of non-atopic mothers. Conclusions These findings suggest that early folic acid or prenatal supplementation among atopic women may be important to prevent wheeze among offspring.

Pediatric asthma comprises different phenotypic clusters with unique nasal microbiotas

BACKGROUND

Pediatric asthma is the most common chronic childhood disease in the USA, currently affecting ~ 7 million children. This heterogeneous syndrome is thought to encompass various disease phenotypes of clinically observable characteristics, which can be statistically identified by applying clustering approaches to patient clinical information. Extensive evidence has shown that the airway microbiome impacts both clinical heterogeneity and pathogenesis in pediatric asthma. Yet, so far, airway microbiotas have been consistently neglected in the study of asthma phenotypes. Here, we couple extensive clinical information with 16S rRNA high-throughput sequencing to characterize the microbiota of the nasal cavity in 163 children and adolescents clustered into different asthma phenotypes.

RESULTS

Our clustering analyses identified three statistically distinct phenotypes of pediatric asthma. Four core OTUs of the pathogenic genera Moraxella, Staphylococcus, Streptococcus, and Haemophilus were present in at least 95% of the studied nasal microbiotas. Phyla (Proteobacteria, Actinobacteria, and Bacteroidetes) and genera (Moraxella, Corynebacterium, Dolosigranulum, and Prevotella) abundances, community composition, and structure varied significantly (0.05 < P ≤ 0.0001) across asthma phenotypes and one of the clinical variables (preterm birth). Similarly, microbial networks of co-occurrence of bacterial genera revealed different bacterial associations across asthma phenotypes.

CONCLUSIONS

This study shows that children and adolescents with different clinical characteristics of asthma also show different nasal bacterial profiles, which is indicative of different phenotypes of the disease. Our work also shows how clinical and microbial information could be integrated to validate and refine asthma classification systems and develop biomarkers of disease.

Breastfeeding and Asthmatic Symptoms in The Offspring of Latinas: The Role of Maternal Nativity

Previous research has generally found exclusive breastfeeding to protect against asthma in young children. However, maternal nativity in a Latina population has not been assessed as a potential confounder or effect modifier. Using cross-sectional data restricted to Latina mothers (n = 704) from a birth cohort in Los Angeles interviewed in 2003 and 2006, we estimated risk ratios (RR) for exclusive breastfeeding and asthmatic symptoms in the offspring. 56 children (8%) had asthmatic symptoms at age 3.5 years. We found a 49% reduction in risk of asthmatic symptoms with >3 months of exclusive breastfeeding (aRR 0.51, 95% CI 0.28, 0.90). Foreign-born Latinas were more likely to initiate and continue breastfeeding for at least 3 months compared with US-born Latinas. Three or more months of exclusive breastfeeding reduced the risk of asthmatic symptoms in the offspring of Latinas, and maternal nativity did not confound or modify this association.

Food consumption and risk of childhood asthma

BACKGROUND

The consumption of foods rich in n-3 polyunsaturated fatty acids has been proposed to protect against childhood asthma. This study explores the association of food consumption (including cow's milk (CM)-free diet) in early life and the risk of atopic and non-atopic asthma.

METHODS

Food intake of 182 children with asthma and 728 matched controls was measured using 3-day food records, within the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) Nutrition Study cohort. The diagnoses of food allergies came both from the written questionnaire and from the registers of the Social Insurance Institution. Conditional logistic regression with generalized estimating equations framework was used in the analyses.

RESULTS

The diagnosis of cow's milk allergy (CMA) led to multiple dietary restrictions still evident at 4 yr of age. Even after adjusting for CMA, higher consumption of CM products was inversely associated with the risk of atopic asthma and higher consumption of breast milk and oats inversely with the risk of non-atopic asthma. Early consumption of fish was associated with a decreased risk of all asthma.

CONCLUSIONS

Dietary intake in early life combined with atopy history has a clear impact on the risk of developing asthma. Our results indicate that CM restriction due to CMA significantly increases and mediates the association between food consumption and childhood asthma risk.

Data-driven asthma endotypes defined from blood biomarker and gene expression data

The diagnosis and treatment of childhood asthma is complicated by its mechanistically distinct subtypes (endotypes) driven by genetic susceptibility and modulating environmental factors. Clinical biomarkers and blood gene expression were collected from a stratified, cross-sectional study of asthmatic and non-asthmatic children from Detroit, MI. This study describes four distinct asthma endotypes identified via a purely data-driven method. Our method was specifically designed to integrate blood gene expression and clinical biomarkers in a way that provides new mechanistic insights regarding the different asthma endotypes. For example, we describe metabolic syndrome-induced systemic inflammation as an associated factor in three of the four asthma endotypes. Context provided by the clinical biomarker data was essential in interpreting gene expression patterns and identifying putative endotypes, which emphasizes the importance of integrated approaches when studying complex disease etiologies. These synthesized patterns of gene expression and clinical markers from our research may lead to development of novel serum-based biomarker panels.