962 research outputs found
Differences in both prevalence and titre of specific immunoglobulin E among children with asthma in affluent and poor communities within a large town in Ghana.
Background Reports from several African countries have noted an increasing prevalence of asthma in areas of extensive urbanization. Objective To investigate the relevance of allergen-specific sensitization and body mass index (BMI) to asthma/wheezing and exercise-induced bronchospasm (EIB) among children from affluent and poorer communities within a large town in Ghana. Methods Children with physician-diagnosed asthma and/or current wheezing aged 9-16 years (n=99; cases) from three schools with differing socio-economic backgrounds [urban affluent (UA), urban poor (UP) or suburban/rural (SR)] were recruited from a cross-sectional study (n=1848) in Kumasi, Ghana, and matched according to age, sex and area of residence with non-asthmatic/non-wheezy controls. We assayed sera for IgE antibodies to mite, cat, dog, cockroach, Ascaris and galactose-α-1,3-galactose. Results Children from the UA school had the lowest total serum IgE. However, cases from the UA school had a higher prevalence and mean titre of sIgE to mite (71.4%, 21.2IU/mL) when compared with controls (14.3%, 0.8IU/mL) or cases from UP (30%, 0.8IU/mL) and SR community (47.8%, 1.6IU/mL). While similar findings were observed with EIB in the whole population, among cases there was no difference in IgE antibody prevalence or titre between children with or without EIB. BMI was higher among UA children with and without asthma; in UP and SR communities, children with EIB (n=14) had a significantly higher BMI compared with children with asthma/wheezing without EIB (n=38) (18.2 vs. 16.4, respectively, P<0.01). Conclusions and Clinical Relevance In the relatively affluent school, asthma/wheezing and EIB were associated with high titre IgE antibodies to mite, decreased total IgE, and increased BMI. This contrasted with children in the urban poor school and suggests that changes relevant to a Western model of childhood asthma can occur within a short geographical distance within a large city in Africa. © 2011 Blackwell Publishing Ltd
Differing associations of BMI and body fat with asthma and lung function in children.
Current evidence suggests that in children there is a significant, albeit weak, association between asthma and obesity. Studies generally use body mass index (BMI) in evaluating body adiposity, but there are limitations to its use.Children from a population-based study attending follow-up (age 11 years) were weighed, measured and had percent body (PBF) and truncal (PTF) fat assessed using bioelectrical impedance. They were skin prick tested and completed spirometry. Parents completed a validated respiratory questionnaire. Children were defined as normal or overweight according to BMI and PBF cut-offs. We tested the association between these adiposity markers with wheeze, asthma, atopy, and lung-function.Six hundred forty-six children (339 male) completed follow-up. BMI z-score, PBF, and PTF were all positively associated with current wheeze (odds ratio [95% CI]: 1.27 [1.03, 1.57], P = 0.03; 1.05 [1.00, 1.09], P = 0.03; 1.04 [1.00, 1.08], P = 0.04, respectively). Similar trends were seen with asthma. However, when examining girls and boys separately, significant positive associations were found with PBF and PTF and asthma but only in girls (gender interaction P = 0.06 and 0.04, respectively). Associations between being overweight and wheezing and asthma were stronger when overweight was defined by PBF (P = 0.007, 0.03) than BMI (P > 0.05). Higher BMI was significantly associated with an increase in FEV(1) and FVC, but only in girls. Conversely, increasing body fat (PBF and PTF) was associated with reduced FEV(1) and FVC, but only in boys. No associations between adiposity and atopy were found.All adiposity measures were associated with wheeze, asthma, and lung function. However, BMI and PBF did not have the same effects and girls and boys appear to be affected differently
Distinguishing Asthma Phenotypes Using Machine Learning Approaches.
Asthma is not a single disease, but an umbrella term for a number of distinct diseases, each of which are caused by a distinct underlying pathophysiological mechanism. These discrete disease entities are often labelled as asthma endotypes. The discovery of different asthma subtypes has moved from subjective approaches in which putative phenotypes are assigned by experts to data-driven ones which incorporate machine learning. This review focuses on the methodological developments of one such machine learning technique-latent class analysis-and how it has contributed to distinguishing asthma and wheezing subtypes in childhood. It also gives a clinical perspective, presenting the findings of studies from the past 5 years that used this approach. The identification of true asthma endotypes may be a crucial step towards understanding their distinct pathophysiological mechanisms, which could ultimately lead to more precise prevention strategies, identification of novel therapeutic targets and the development of effective personalized therapies
Лечебно-диагностический алгоритм при очаговых тиреопатиях
Представлены современные данные о возможности развития тиреоидного рака на фоне доброкачественной патологии щитовидной железы, определены группы риска по развитию тиреоидных карцином. Разработан диагностический алгоритм своевременной и ранней диагностики рака щитовидной железы, предложены терапевтические подходы, направленные на предупреждение развития тиреоидного рака.Contemporary data about the possibility of thyroid carcinoma development against a background of thyroid pathology are presented. Risk groups of thyroid carcinoma development were determined. A diagnostic algorithm of timely and early diagnosis of thyroid carcinoma was worked out. Therapeutic approaches to prevention of thyroid cancer are suggested
Epistasis between FLG and IL4R genes on the risk of allergic sensitization: results from two population-based birth cohort studies
Immune-specifc genes as well as genes responsible for the formation and integrity of the epidermal barrier have been implicated in the pathogeneses of allergic sensitization. This study sought to determine whether an epistatic efect (gene-gene interaction) between genetic variants within interleukin 4 receptor (IL4R) and flaggrin (FLG) genes predispose to the development of allergic sensitization. Data from two birth cohort studies were analyzed, namely the Isle of Wight (IOW; n=1,456) and the Manchester Asthma and Allergy Study (MAAS; n=1,058). In the IOW study, one interaction term (IL4R rs3024676×FLG variants) showed statistical signifcance (interaction term: P=0.003). To illustrate the observed epistasis, stratifed analyses were performed, which showed that FLG variants were associated with allergic sensitization only among IL4R rs3024676 homozygotes (OR, 1.97; 95% CI, 1.27–3.05; P=0.003). In contrast, FLG variants efect was masked among IL4R rs3024676 heterozygotes (OR, 0.53; 95% CI, 0.22–1.32; P=0.175). Similar results were demonstrated in the MAAS study. Epistasis between immune (IL4R) and skin (FLG) regulatory genes exist in the pathogenesis of allergic sensitization. Hence, genetic susceptibility towards defective epidermal barrier and deviated immune responses could work together in the development of allergic sensitization
Genome-wide association and HLA fine-mapping studies identify risk loci and genetic pathways underlying allergic rhinitis
Allergic rhinitis is the most common clinical presentation of allergy, affecting 400 million people worldwide, with increasing incidence in westernized countries1,2. To elucidate the genetic architecture and understand the underlying disease mechanisms, we carried out a meta-analysis of allergic rhinitis in 59,762 cases and 152,358 controls of European ancestry and identified a total of 41 risk loci for allergic rhinitis, including 20 loci not previously associated with allergic rhinitis, which were confirmed in a replication phase of 60,720 cases and 618,527 controls. Functional annotation implicated genes involved in various immune pathways, and fine mapping of the HLA region suggested amino acid variants important for antigen binding. We further performed genome-wide association study (GWAS) analyses of allergic sensitization against inhalant allergens and nonallergic rhinitis, which suggested shared genetic mechanisms across rhinitis-related traits. Future studies of the identified loci and genes might identify novel targets for treatment and prevention of allergic rhinitis
Evolution of IgE responses to multiple allergen components throughout childhood
BACKGROUND: There is a paucity of information about longitudinal patterns of IgE responses to allergenic proteins (components) from multiple sources. OBJECTIVE: To investigate temporal patterns of component-specific IgE responses from infancy to adolescence, and their relationship with allergic diseases. METHODS: In a population-based birth cohort, we measured IgE to 112 components at 6 follow-ups during childhood. We used a Bayesian method to discover cross-sectional sensitization patterns and their longitudinal trajectories, and related these patterns to asthma and rhinitis in adolescence. RESULTS: We identified one sensitization cluster at age one, 3 at age three, 4 at ages five and eight, 5 at age 11, and six at age 16 years. "Broad" cluster was the only cluster present at every follow-up, comprising of components from multiple sources. "Dust mite" cluster formed at age three and remained unchanged to adolescence. At age three, a single-component "Grass" cluster emerged, which at age five absorbed additional grass components and Fel d 1 to form the "Grass/cat" cluster. Two new clusters formed at age 11: "Cat" cluster and "PR-10/profilin" (which divided at age 16 into "PR-10" and "Profilin"). The strongest contemporaneous associate of asthma at age 16 years was sensitization to "Dust mite" cluster (OR [95% CI]: 2.6 [1.2-6.1], P<0.05), but the strongest early-life predictor of subsequent asthma was sensitization to "Grass/cat" cluster (3.5 [1.6-7.4], P<0.01). CONCLUSIONS: We describe the architecture of the evolution of IgE responses to multiple allergen components throughout childhood, which may facilitate development of better diagnostic and prognostic biomarkers for allergic diseases
Diagnosis of asthma in symptomatic children based on measures of lung function: an analysis of data from a population-based birth cohort study.
BACKGROUND: Concerns have been expressed about asthma overdiagnosis. The UK National Institute of Health and Care Excellence (NICE) proposed a new diagnostic algorithm applying four lung function measures sequentially (ratio of forced expiratory volume in 1 s [FEV1] to forced vital capacity [FVC] 20%). We aimed to assess the diagnostic value of three of the tests individually, and then test the proposed algorithm in symptomatic children. METHODS: We used follow-up data at age 13-16 years from the Manchester Asthma and Allergy Study, a prospective, population-based, birth cohort study. We initially present results for the whole population, then by subgroup of disease. To simulate the situation in primary care, we included participants reporting symptoms of wheeze, cough, or breathlessness in the previous 12 months and who were not on regular inhaled corticosteroids. We used an epidemiological definition of current asthma, defined as all three of physician-diagnosed asthma, current wheeze, and current use of asthma treatment, reported by parents in a validated questionnaire. We assigned children with negative answers to all three questions as non-asthmatic controls. We also measured spirometry, bronchodilator reversibility, and FeNO at follow-up; data for peak expiratory flow variability were not available. We calculated the proportion of participants with a current positive lung function test at each step of the algorithm, and recorded the number of participants that met our definition of asthma. FINDINGS: Of 1184 children born into the cohort, 772 attended follow-up at age 13-16 years between July 22, 2011, and Nov 11, 2014. Among 630 children who completed spirometry, FEV1:FVC was less than 70% in ten (2%) children, of whom only two (20%) had current asthma. Bronchodilator reversibility was positive in 54 (9%) of 624 children, of whom only 12 (22%) had current asthma. FeNO was 35 or more parts per billion in 115 (24%) of 485 children, of whom 29 (25%) had current asthma. Only four of 56 children with current asthma had positive results for all three tests (spirometry, bronchodilator reversibility, and FeNO). Conversely, 24 (43%) of the 56 children with current asthma were negative on all three tests. FEV1:fvc (p=0·0075) and FeNO (p<0·0001), but not bronchodilator reversibility (p=0·97), were independently associated with asthma in multivariable logistic regression models. Among children who reported recent symptoms, the diagnostic accuracy of the algorithm was poor. INTERPRETATION: Our findings challenge the proposed cutoff values for spirometry, the order in which the lung function tests are done, and the position of bronchodilator reversibility within the algorithm sequence. Until better evidence is available, the proposed NICE algorithm on asthma diagnosis should not be implemented in children. FUNDING: UK Medical Research Council
Body mass index in young children and allergic disease: Gender differences in a longitudinal study
The increase in allergic diseases has occurred in parallel with the obesity epidemic, suggesting a possible association.Objective We investigated the relationship of body mass index (BMI) up to age 8 years with allergic disease within a birth cohort.Methods Children were followed from birth and were reviewed at age 3, 5 and 8 years (n=731; male 406). Parents completed questionnaires; children were weighed, measured, skin prick tested and examined.Results Increasing BMI at 3, 5 and 8 years increased the risk of current wheezing at the corresponding age (odds ratio [95% confidence interval] per standardized deviation score: age 3, 1.26 [1.04-1.53], P=0.02; age 5, 1.33 [1.06-1.67], P=0.02; age 8, 1.27 [1.0-1.62], P=0.05). The effect of BMI on wheeze at age 8 years differed between boys and girls, with a significant positive association in girls, but not in boys (P=0.04 for interaction). The effect of BMI at earlier ages on current or subsequent wheezing did not differ significantly between genders. Increasing BMI significantly increased the risk of physician-diagnosed eczema at age 5 (1.23 [1.04-1.47], P=0.02) and 8 (1.23 [1.03-1.45], P=0.02), with a significant interaction between gender and BMI at age 5 (P=0.04). There was no association between BMI and sensitization. Being overweight at age 3 years was significantly associated with late-onset wheeze (3.83 [1.51-9.75], P=0.005), persistent wheeze (4.15 [2.07-8.32],
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