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Rationale: The strongest genetic risk factor for childhood-onset asthma, the 17q21 locus, is associated with increased viral susceptibility and disease-promoting processes.Objectives: To identify biological targets underlying the escalated viral susceptibility associated with the clinical phenotype mediated by the 17q21 locus.Methods: Genome-wide transcriptome analysis of nasal brush samples from 261 children (78 healthy, 79 with wheezing at preschool age, 104 asthmatic) within the ALLIANCE (All-Age-Asthma) cohort, with a median age of 10.0 (range, 1.0-20.0) years, was conducted to explore the impact of their 17q21 genotype (SNP rs72163891). Concurrently, nasal secretions from the same patients and visits were collected, and high-sensitivity mesoscale technology was employed to measure IFN protein levels.Measurements and Main Results: This study revealed that the 17q21 risk allele induces a genotype- and asthma/wheeze phenotype-dependent enhancement of mucosal GSDMB expression as the only relevant 17q21-encoded gene in children with preschool wheeze. Increased GSDMB expression correlated with the activation of a type-1 proinflammatory, cell-lytic immune, and natural killer signature, encompassing key genes linked to an IFN type-2-signature (IFNG, CXCL9, CXCL10, KLRC1, CD8A, GZMA). Conversely, there was a reduction in IFN type 1 and type 3 expression signatures at the mRNA and protein levels.Conclusions: This study demonstrates a novel disease-driving mechanism induced by the 17q21 risk allele. Increased mucosal GSDMB expression is associated with a cell-lytic immune response coupled with compromised airway immunocompetence. These findings suggest that GSDMB-related airway cell death and perturbations in the mucosal IFN signature account for the increased vulnerability of 17q21 risk allele carriers to respiratory viral infections during early life, opening new options for future biological interventions.The All-Age-Asthma (ALLIANCE) cohort is registered at www.clinicaltrials.gov (pediatric arm, NCT02496468).
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Asma , Preescolar , Niño , Humanos , Lactante , Adolescente , Adulto Joven , Adulto , Anciano de 80 o más Años , Genotipo , Fenotipo , Alelos , ARN Mensajero , Predisposición Genética a la Enfermedad/genética , Polimorfismo de Nucleótido Simple/genéticaRESUMEN
INTRODUCTION: Eosinophil-derived neurotoxin (EDN) is a biomarker for eosinophilic activation. Urinary (u) EDN may allow non-invasive monitoring of asthma, but clinical recommendations are lacking. We assessed the potential of uEDN as a marker of disease activity in pediatric asthma. METHODS: We assessed urine samples of 371 children from the German ALLIANCE study cohort, from which we had: 169 preschool wheezers (<6 years), 80 asthmatics (≥6 years), and 122 healthy controls using the ImmunoCAP™ EDN Assay. Creatinine (Cr)-adjusted uEDN values were analyzed using correlations, association tests, (non) parametric statistics, multiple linear, and multivariable regression. RESULTS: uEDN/uCr values were higher in atopic versus non-atopic preschool-aged subjects (p = .035) and associated with the sum of allergen-specific IgE in younger (r = 0.24, p = .003), and older subjects (r = 0.23, p = .043). uEDN/uCr was marginally a good determinant for atopy (p = .078, for subjects aged <6 years, and p = .058 for subjects ≥6 years). Children with the T2-high phenotype had higher uEDN/uCr (p < .001) versus T2-low-irrespective of using uEDN/uCr or blood eosinophils in combination to allergen sIgE for disease phenotyping. uEDN/uCr significantly correlated with reduced lung function among asthmatics (FEV1 z-scores: r = -0.30, p = .007, and FEV1/FVC z-scores: r = -0.24, p = .038). Using multivariable modeling, uEDN/uCr was an independent determinant of FEV1 (p = .038), and to a lesser extent, FEV1/FVC (p = .080). CONCLUSIONS: uEDN/uCr may serve as a non-invasive biomarker for clinical features such as lung function in pediatric asthma. We highlight the utility of uEDN/uCr as a biomarker that can be easily assessed using widely available robust diagnostic immunoassays.
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Asma , Biomarcadores , Neurotoxina Derivada del Eosinófilo , Humanos , Asma/orina , Asma/diagnóstico , Asma/fisiopatología , Neurotoxina Derivada del Eosinófilo/orina , Masculino , Femenino , Niño , Preescolar , Biomarcadores/orina , Eosinófilos/inmunología , Inmunoglobulina E/sangre , Pulmón/fisiopatología , Pruebas de Función Respiratoria/métodos , AdolescenteRESUMEN
Rationale: In murine models, microbial exposures induce protection from experimental allergic asthma through innate immunity. Objectives: 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 T-helper cell type 2 (Th2), Th1, and Th17 cytokine expression at age 1 year was measured after stimulation of peripheral blood mononuclear cells with 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 first year of life was assessed by weekly diaries and asthma by questionnaire at age 6 years. Measurements and Main 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% confidence interval [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.
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Asma , Cromosomas Humanos Par 17 , Lipopolisacáridos , Alelos , Animales , Asma/genética , Bovinos , Citocinas/genética , Femenino , Humanos , Inmunidad Innata , Leucocitos Mononucleares , Ratones , Ruidos Respiratorios/genéticaRESUMEN
RATIONALE: In adults, personalised asthma treatment targets patients with type 2 (T2)-high and eosinophilic asthma phenotypes. It is unclear whether such classification is achievable in children. OBJECTIVES: To define T2-high asthma with easily accessible biomarkers and compare resulting phenotypes across all ages. METHODS: In the multicentre clinical All Age Asthma Cohort (ALLIANCE), 1125 participants (n=776 asthmatics, n=349 controls) were recruited and followed for 2â years (1â year in adults). Extensive clinical characterisation (questionnaires, blood differential count, allergy testing, lung function and sputum induction (in adults)) was performed at baseline and follow-ups. Interleukin (IL)-4, IL-5 and IL-13 were measured after stimulation of whole blood with lipopolysaccharide (LPS) or anti-CD3/CD28. MEASUREMENTS AND MAIN RESULTS: Based on blood eosinophil counts and allergen-specific serum IgE antibodies, patients were categorised into four mutually exclusive phenotypes: "atopy-only", "eosinophils-only", "T2-high" (eosinophilia + atopy) and "T2-low" (neither eosinophilia nor atopy). The T2-high phenotype was found across all ages, even in very young children in whom it persisted to a large degree even after 2â years of follow-up. T2-high asthma in adults was associated with childhood onset, suggesting early origins of this asthma phenotype. In both children and adults, the T2-high phenotype was characterised by excessive production of specific IgE to allergens (p<0.0001) and, from school age onwards, by increased production of IL-5 after anti-CD3/CD28 stimulation of whole blood. CONCLUSIONS: Using easily accessible biomarkers, patients with T2-high asthma can be identified across all ages delineating a distinct phenotype. These patients may benefit from therapy with biologicals even at a younger age.
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Asma , Eosinofilia , Alérgenos , Biomarcadores , Antígenos CD28/genética , Eosinófilos , Humanos , Inmunoglobulina E , Interleucina-13 , Interleucina-5 , Lipopolisacáridos , Longevidad , FenotipoRESUMEN
BACKGROUND: Comprehensive studies investigated the role of T-cells in asthma which led to personalised treatment options targeting severe eosinophilic asthma. However, little is known about the contribution of B-cells to this chronic inflammatory disease. In this study we investigated the contribution of various B-cell populations to specific clinical features in asthma. METHODS: In the All Age Asthma Cohort (ALLIANCE), a subgroup of 154 adult asthma patients and 28 healthy controls were included for B-cell characterisation by flow cytometry. Questionnaires, lung function measurements, blood differential counts and allergy testing of participants were analysed together with comprehensive data on B-cells using association studies and multivariate linear models. RESULTS: Patients with severe asthma showed decreased immature B-cell populations while memory B-cells were significantly increased compared with both mild-moderate asthma patients and healthy controls. Furthermore, increased frequencies of IgA+ memory B-cells were associated with impaired lung function and specifically with parameters indicative for augmented resistance in the peripheral airways. Accordingly, asthma patients with small airway dysfunction (SAD) defined by impulse oscillometry showed increased frequencies of IgA+ memory B-cells, particularly in patients with mild-moderate asthma. Additionally, IgA+ memory B-cells significantly correlated with clinical features of SAD such as exacerbations. CONCLUSIONS: With this study we demonstrate for the first time a significant association of increased IgA+ memory B-cells with asthma and SAD, pointing towards future options for B-cell-directed strategies in preventing and treating asthma.
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Asma , Adulto , Humanos , Espirometría , Oscilometría , Sistema Respiratorio , Inmunoglobulina ARESUMEN
BACKGROUND: During COVID-19-related public health non-pharmaceutical prevention measures, such as social distancing, lockdown periods and use of face masks, a decrease in viral respiratory and gastroenterological infections was observed worldwide. Following discontinuation of preventative measures, a potential increase of respective infections outside of their usual seasons was a matter of concern. METHOD: We aimed to illustrate annual distribution of confirmed viral infections between 2017 and 2021 based on 32,506 clinical samples in a German pediatric tertiary care center and to explore the impact of the COVID-19 pandemic on the epidemiology of these infections in children. RESULTS: While a decrease in overall viral infections was observed during the first and second lockdown period, an extraordinary increase in the number of viral respiratory infections, predominantly caused by human Rhino-/Enterovirus and respiratory syncytial virus (RSV), was observed after relaxation of preventive measures. Notably, Rhino-/Enterovirus infections increased 4-fold (2020 vs. 2019) and 16-fold (2021 vs. 2019). The occurrence of RSV was observed beginning from June to August 2021 and reached an all-time record with a 25- to 50-fold increase in numbers in September and October 2021 in relation to previous pre-pandemic years (2017-2019). In contrast, for non-respiratory viruses (i.e. Rota-/Norovirus), the effect on respective seasonal patterns was only minimal compared to previous years. CONCLUSION: The observed increase in respiratory infections in children is worrying and is already causing hospitals to become overburdened. Enhanced vigilance will be key to face clinical challenges due to these epidemiological changes in viral disease patterns in the months to come.
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COVID-19 , Infecciones del Sistema Respiratorio , COVID-19/epidemiología , COVID-19/prevención & control , Niño , Control de Enfermedades Transmisibles , Humanos , Pandemias/prevención & control , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/prevención & control , SARS-CoV-2RESUMEN
BACKGROUND: Phenotypes of childhood-onset asthma are characterized by distinct trajectories and functional features. For atopy, definition of phenotypes during childhood is less clear. OBJECTIVE: We sought to define phenotypes of atopic sensitization over the first 6 years of life using a latent class analysis (LCA) integrating 3 dimensions of atopy: allergen specificity, time course, and levels of specific IgE (sIgE). METHODS: Phenotypes were defined by means of LCA in 680 children of the Multizentrische Allergiestudie (MAS) and 766 children of the Protection against allergy: Study in Rural Environments (PASTURE) birth cohorts and compared with classical nondisjunctive definitions of seasonal, perennial, and food sensitization with respect to atopic diseases and lung function. Cytokine levels were measured in the PASTURE cohort. RESULTS: The LCA classified predominantly by type and multiplicity of sensitization (food vs inhalant), allergen combinations, and sIgE levels. Latent classes were related to atopic disease manifestations with higher sensitivity and specificity than the classical definitions. LCA detected consistently in both cohorts a distinct group of children with severe atopy characterized by high seasonal sIgE levels and a strong propensity for asthma; hay fever; eczema; and impaired lung function, also in children without an established asthma diagnosis. Severe atopy was associated with an increased IL-5/IFN-γ ratio. A path analysis among sensitized children revealed that among all features of severe atopy, only excessive sIgE production early in life affected asthma risk. CONCLUSIONS: LCA revealed a set of benign, symptomatic, and severe atopy phenotypes. The severe phenotype emerged as a latent condition with signs of a dysbalanced immune response. It determined high asthma risk through excessive sIgE production and directly affected impaired lung function.
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Hipersensibilidad/inmunología , Alérgenos/inmunología , Niño , Preescolar , Estudios de Cohortes , Citocinas/sangre , Femenino , Volumen Espiratorio Forzado , Humanos , Hipersensibilidad/sangre , Hipersensibilidad/fisiopatología , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , Lactante , Masculino , FenotipoRESUMEN
BACKGROUND: IL-33 polymorphisms influence the susceptibility to asthma. IL-33 indirectly induces Th2-immune responses via dendritic cell activation, being important for development of atopic diseases. Furthermore, IL-33 upregulates regulatory T cells (Tregs), which are critical for healthy immune homeostasis. This study investigates associations between IL-33 polymorphisms during the development of childhood atopic diseases and underlying mechanisms including immune regulation of Tregs. METHODS: Genotyping of IL-33-polymorphisms (rs928413, rs1342326) was performed by MALDI-TOF-MS in 880 of 1133 PASTURE/EFRAIM children. In 4.5-year-old German PASTURE/EFRAIM children (n = 99), CD4+ CD25high FOXP3+ Tregs were assessed by flow cytometry following 24-h incubation of PBMCs with PMA/ionomycin, LPS or without stimuli (U). SOCS3, IL1RL1, TLR4 mRNA expression and sST2 protein levels ex vivo were measured in PASTURE/EFRAIM children by real-time PCR or ELISA, respectively. Health outcomes (hay fever, asthma) were assessed by questionnaires at the age of 6 years. RESULTS: rs928413 and rs1342326 were positively associated with hay fever (OR = 1.77, 95%CI = 1.02-3.08; OR = 1.79, 95%CI = 1.04-3.11) and CD4+ CD25high FOXP3+ Tregs (%) decreased in minor allele homozygotes/heterozygotes compared to major allele homozygotes (p(U) = 0.004; p(LPS) = 0.005; p(U) = 0.001; p(LPS) = 0.012). SOCS3 mRNA expression increased in minor allele homozygotes and heterozygotes compared with major allele homozygotes for both IL-33-polymorphisms (p(rs928413) = 0.032, p(rs1342326) = 0.019) and negatively correlated to Tregs. CONCLUSIONS: IL-33-polymorphisms rs928413 and rs1342326 may account for an increased risk of hay fever with the age of 6 years. Lower Tregs and increased SOCS3 in combined heterozygotes and minor allele homozygotes may be relevant for hay fever development, pointing towards dysbalanced immune regulation and insufficient control of allergic inflammation.
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Interleucina-33/genética , Rinitis Alérgica Estacional/genética , Proteína 3 Supresora de la Señalización de Citocinas/metabolismo , Linfocitos T Reguladores/inmunología , Células Cultivadas , Niño , Preescolar , Estudios de Cohortes , Femenino , Factores de Transcripción Forkhead/metabolismo , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Genotipo , Alemania , Humanos , Masculino , Polimorfismo de Nucleótido Simple , Riesgo , Proteína 3 Supresora de la Señalización de Citocinas/genéticaRESUMEN
RATIONALE: The early hygiene hypothesis explained the development of allergies by a lack of infections; nowadays, the aspect of excessive cleanliness in affluent populations seems to have replaced this concept. Yet, no investigation has shown that home or personal cleanliness relate to allergic diseases. OBJECTIVES: To relate personal and home cleanliness to risk of asthma and allergies. METHODS: Comprehensive questionnaire information on home or personal cleanliness and allergic health conditions at school age was collected in 399 participants of the urban Perinatale Asthma Umwelt Langzeit Allergie Studie (PAULA) birth cohort. Bacterial markers were assessed in floor and mattress dust and were related to cleanliness and allergic diseases. MEASUREMENTS AND MAIN RESULTS: Personal cleanliness was inversely related to bacterial compounds on floors and mattresses, whereas home cleanliness effectively reduced dust amount but not microbial markers. Exposure to muramic acid related to a lower prevalence of school-age asthma (adjusted odds ratio, 0.59 [95% confidence interval, 0.39; 0.90]). Mattress endotoxin in the first year of life was inversely associated with atopic sensitization (0.73 [0.56-0.96]) and asthma at school age (0.72 [0.55-0.95]). Despite the associations of dust parameters both with cleanliness and allergic health conditions, the development of allergies was not related to home and personal cleanliness. CONCLUSIONS: Bacterial exposure in house dust determined childhood asthma and allergies. Personal cleanliness, such as washing hands, and home cleanliness were objectively reflected by dust parameters in homes. However, neither personal nor home cleanliness was associated with a risk for asthma and allergies. Other microbial components in house dust not affected by personal hygiene are likely to play a role.
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Asma/inmunología , Polvo , Hipótesis de la Higiene , Higiene , Polvo/análisis , Polvo/inmunología , Endotoxinas/análisis , Humanos , Hipersensibilidad/inmunología , Estilo de Vida , Ácidos Murámicos/análisis , Medición de RiesgoAsunto(s)
Hipersensibilidad Inmediata , Niño , Humanos , Prevalencia , Ruidos Respiratorios/etiología , Factores de Riesgo , Población RuralRESUMEN
BACKGROUND: Previous studies suggested that maternal farm exposure during pregnancy modulates early immune development toward an allergy-protective status potentially mediated by TH1 or regulatory T (Treg) cells. However, the underlying mechanisms might involve immune modulation of additional T-cell populations, such as TH17 cells, influenced by genetic predisposition. OBJECTIVE: We examined the role of maternal farm exposure and genetic predisposition on TH17 cell responses to innate and adaptive immune stimulation in cord blood. METHODS: Eighty-four pregnant mothers were recruited before delivery. Detailed questionnaires (60 nonfarming mother, 22 farming mothers, and 2 exclusions) assessed farming exposures. Cord blood was stimulated with lipid A, peptidoglycan (Ppg), or PHA. TH17 lineage (retinoic acid receptor-related orphan receptor C [RORC], retinoic acid receptor-related orphan receptor α [RORA], IL-23 receptor [IL23R], IL17, IL17F, and IL22) and Treg cell markers (forkhead box protein 3 [FOXP3], lymphocyte activation gene 3 [LAG3], and glucocorticoid-induced TNF receptor [GITR]) were assessed at the mRNA level. TH17/Treg/TH1/TH2 cytokines and 7 single nucleotide polymorphisms within the TH17 lineage (RORC, IL23R, and IL17) were examined. RESULTS: TH17 lineage mRNA markers were expressed at birth at low concentrations independent of maternal farm exposure. A positive correlation between TH17 lineage markers and FOXP3 (mRNA) was observed on stimulation (nonfarming mothers: lipid A, Ppg, and PHA; farming mothers: Ppg and PHA), influenced by maternal farming. Specific single nucleotide polymorphisms within the TH17 lineage genes influenced gene expression of TH17 and Treg cell markers and cytokine secretion. CONCLUSIONS: Gene expression of TH17 lineage markers in cord blood was not influenced by maternal farming. Yet TH17 and Treg cell markers were positively correlated and influenced by maternal farm exposure. Our data suggest that prenatal exposures and genetic predisposition play a role during early TH17 immune maturation, potentially regulating the development of immune-mediated diseases, such as childhood asthma.
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Animales Domésticos , Exposición a Riesgos Ambientales , Sangre Fetal/inmunología , Exposición Materna , Células Th17/inmunología , Animales , Biomarcadores , Femenino , Factores de Transcripción Forkhead/genética , Humanos , Hipersensibilidad/prevención & control , Polimorfismo de Nucleótido Simple , Embarazo , ARN Mensajero/sangre , Linfocitos T Reguladores/inmunologíaRESUMEN
The gold standard for assessing quality of forced expiratory manoeuvres is visual inspection by an expert. American Thoracic Society/European Respiratory Society numerical quality criteria (NQC) include back-extrapolated volume (BEV), repeatability and forced expiratory time (FET). Equipment currently available provides feedback tempting the investigator to use NQC as pass-fail criterion. To investigate whether using NQC instead of visual acceptability is a valid option, we analysed data from a multicentre national reference study in Germany of children aged 4-18 years. Spirometry was performed under field conditions. Receiver operating characteristic analysis was used to assess performance of BEV, repeatability, FET and a combination thereof in relation to visual acceptability. We included data from 3133 healthy Caucasians in the analyses; 72% delivered at least two visually acceptable manoeuvres. Of these, 59% would have been rejected based on combined NQC, mainly because the FET criterion was not feasible. Specificity of the NQC was generally low (BEV 10%, repeatability 30% and FET 50%). Receiver operating characteristic analysis showed that a combination of the three measures could reach at best a sensitivity of 90% and specificity of 56%. We conclude that visual control is mandatory and NQC may help obtain the best possible results, but a fixed cut-off for FET should be abandoned.
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Neumología/organización & administración , Neumología/normas , Espirometría/métodos , Adolescente , Algoritmos , Niño , Preescolar , Diagnóstico por Computador , Espiración , Femenino , Volumen Espiratorio Forzado , Alemania , Humanos , Masculino , Modelos Teóricos , Variaciones Dependientes del Observador , Curva ROC , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Programas Informáticos , Encuestas y Cuestionarios , Estados Unidos , Capacidad VitalRESUMEN
BACKGROUND: An early IgE response to grass or birch pollen can anticipate seasonal allergic rhinitis to pollen later in life or remain clinically silent. OBJECTIVE: To identify risk factors early in life that allow discriminating pathogenic from non-pathogenic IgE responses and contribute to the development of seasonal allergic rhinitis to grass pollen. METHODS: The German Multicentre Allergy Study examined a birth cohort born in 1990. A questionnaire was yearly administered and blood samples collected at age 1,2,3,5,6,7,10,13 yr. The definition of the primary outcome grass- and birch-pollen-related seasonal allergic rhinitis (SARg, SARb) was based on nasal symptoms in June/July and April, respectively. Serum IgE antibodies to Phleum pratense and Betula verrucosae extracts were monitored with immune-enzymatic singleplex assays. RESULTS: Of the 820 examined children, 177 and 148 developed SARg and SARb, respectively. Among healthy children aged 3 or more years, IgE to grass pollen was the strongest risk factor of SARg (OR 10.39, 95%CI 6.1-17.6, p < 0.001), while parental hay fever was the only risk factor in early childhood independently associated with future SARg (1 parent: OR 2.56, 95%CI 1.4-4.5, p < 0.001; 2 parents: OR 4.17, 95%CI 1.7-10.1) and SARb (1 parent OR: 5.21, 95%CI 2.20-12.4, p < 0.001; 2 parents: OR 8.02, 95%CI 2.0-32.9, p < 0.001). Parental hay fever was associated with an increase of the concentration of pollen-specific IgE in seropositive subjects, after the age of 6 and was also a hallmark of molecularly more complex specific IgE responses to grass or birch pollen at age 6 or older. CONCLUSIONS: Parental hay fever and specific IgE to grass and/or birch pollen are strong pre-clinical determinants and potentially good predictors of seasonal allergic rhinitis.
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Hijo de Padres Discapacitados , Inmunoglobulina E/inmunología , Polen/inmunología , Rinitis Alérgica Estacional/epidemiología , Rinitis Alérgica Estacional/inmunología , Adolescente , Alérgenos/inmunología , Antígenos de Plantas/inmunología , Betula/inmunología , Biomarcadores/sangre , Niño , Preescolar , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Alemania/epidemiología , Humanos , Inmunoglobulina E/sangre , Masculino , Phleum/inmunología , Valor Predictivo de las PruebasRESUMEN
BACKGROUND: In most children with asthma and atopy, onset of disease occurs early in life, indicating a crucial role of in utero and early childhood environment. However, only a small part of this burden of disease established early in life has been explained. OBJECTIVE: To examine the effects of early environmental exposures on the development of asthma and atopy within the setting of an affluent urban population. METHODS: The authors followed 526 German children from birth to 5 years of age. Parental interviews in pregnancy and then yearly assessed the health of the child and environmental characteristics. Endotoxin and allergens in house dust were measured at 3 months. Atopic sensitization was assessed at 1 and 5 years. RESULTS: In atopic mothers, acute atopic symptoms during pregnancy were associated with increased risk of early atopic dermatitis (adjusted odds ratio [aOR] 1.74, 95% confidence interval [CI] 1.00-3.02) and allergic rhinitis at 5 years (aOR 2.11, 95% CI 1.01-4.41). Further, maternal illnesses during pregnancy (ie, repeated common colds) increased the risk of asthma at 5 years (aOR 2.31, 95% CI 1.12-4.78). Endotoxin in the child's mattress was inversely associated with atopic sensitization (aOR 0.79, 95% CI 0.64-0.97) and asthma (aOR 0.71, 95% CI 0.55-0.93). A contrasting effect of early endotoxin and mite exposure was observed for mite sensitization: mite exposure increased the risk of mite sensitization at 5 years (aOR 1.30, 95% CI 1.11-1.53), whereas endotoxin exposure was inversely associated with mite sensitization (aOR 0.73, 95% CI 0.57-0.95). CONCLUSION: Factors affecting the in utero environment, such as maternal atopy and infections, and bacterial exposure in pregnancy or early life may act as immunomodulators enhancing or inhibiting the development of asthma and atopy in childhood.
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Asma/inmunología , Hipersensibilidad Inmediata/inmunología , Atención Perinatal/métodos , Efectos Tardíos de la Exposición Prenatal/inmunología , Animales , Antígenos Dermatofagoides/inmunología , Proteínas de Artrópodos/inmunología , Asma/diagnóstico , Asma/epidemiología , Preescolar , Cisteína Endopeptidasas/inmunología , Dermatophagoides farinae/inmunología , Dermatophagoides pteronyssinus/inmunología , Endotoxinas/inmunología , Femenino , Humanos , Hipersensibilidad Inmediata/diagnóstico , Hipersensibilidad Inmediata/epidemiología , Lactante , Recién Nacido , Estudios Longitudinales , Masculino , Atención Perinatal/tendencias , Embarazo , Efectos Tardíos de la Exposición Prenatal/diagnóstico , Población Urbana/clasificaciónRESUMEN
BACKGROUND: IL10 encodes for IL-10, an important anti-inflammatory cytokine with pleiotropic effects. It is crucial for development of immune tolerance, downregulates expression of TH1 cytokines, and is relevant for T-cell regulation. Several IL10 single nucleotide polymorphisms (SNPs) were associated with inflammatory diseases, such as atopic diseases, which might have their onset during early immune maturation. OBJECTIVE: We hypothesized that IL10 SNPs are associated with decreased regulatory T (Treg) cell numbers, TH2-skewed immune responses, and decreased IFN-γ levels in cord blood parallel with increased proinflammatory markers, subsequently leading to increased atopic diseases until 3 years. METHODS: Eight genetic IL10 variants, represented by 4 linkage disequilibrium blocks (R(2) > 0.80) and 2 distal promoter SNPs, were genotyped in cord blood mononuclear cells of 200 healthy neonates. Cord blood mononuclear cells were cultured unstimulated or after stimulation with lipid A, peptidoglycan, PHA, house dust mite (Der p 1), or Der p 1 plus lipid A. mRNA expression of Treg cell-associated genes (forkhead box protein P3 [FOXP3], glucocorticoid-induced TNF receptor [GITR], lymphocyte activation gene 3 [LAG3]), TH1/TH2 cytokines, TNF-α, and GM-CSF were assessed. Atopic and respiratory outcomes (atopic dermatitis [AD] and wheeze) were assessed by means of questionnaire at age 3 years. RESULTS: Carriers of 3 IL10 SNP blocks and both distal promoter SNPs showed reduced expression of Treg cell markers, reduced IL-5 levels, proinflammatory TNF-α and GM-CSF, and partially increased IFN-γ levels. The same SNPs presented as determinant for AD, wheeze, or symptoms of AD, wheeze, or both at age 3 years. CONCLUSIONS: Polymorphisms in IL10 influenced Treg cell marker expression and TH1/TH2 and proinflammatory cytokine secretion early in life. This was relevant for further development of immune-mediated diseases, such as AD and wheeze, in early childhood.
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Dermatitis Atópica/genética , Interleucina-10/genética , Ruidos Respiratorios/genética , Preescolar , Dermatitis Atópica/inmunología , Sangre Fetal/inmunología , Genotipo , Humanos , Recién Nacido , Interleucina-10/inmunología , Leucocitos Mononucleares , Polimorfismo de Nucleótido Simple , ARN Mensajero/metabolismo , Ruidos Respiratorios/inmunología , Linfocitos T Reguladores/inmunología , Células TH1/inmunología , Células Th2/inmunologíaRESUMEN
BACKGROUND: Studies on the association of farm environments with asthma and atopy have repeatedly observed a protective effect of farming. However, no single specific farm-related exposure explaining this protective farm effect has consistently been identified. OBJECTIVE: We sought to determine distinct farm exposures that account for the protective effect of farming on asthma and atopy. METHODS: In rural regions of Austria, Germany, and Switzerland, 79,888 school-aged children answered a recruiting questionnaire (phase I). In phase II a stratified random subsample of 8,419 children answered a detailed questionnaire on farming environment. Blood samples and specific IgE levels were available for 7,682 of these children. A broad asthma definition was used, comprising symptoms, diagnosis, or treatment ever. RESULTS: Children living on a farm were at significantly reduced risk of asthma (adjusted odds ratio [aOR], 0.68; 95% CI, 0.59-0.78; P< .001), hay fever (aOR, 0.43; 95% CI, 0.36-0.52; P< .001), atopic dermatitis (aOR, 0.80; 95% CI, 0.69-0.93; P= .004), and atopic sensitization (aOR, 0.54; 95% CI, 0.48-0.61; P< .001) compared with nonfarm children. Whereas this overall farm effect could be explained by specific exposures to cows, straw, and farm milk for asthma and exposure to fodder storage rooms and manure for atopic dermatitis, the farm effect on hay fever and atopic sensitization could not be completely explained by the questionnaire items themselves or their diversity. CONCLUSION: A specific type of farm typical for traditional farming (ie, with cows and cultivation) was protective against asthma, hay fever, and atopy. However, whereas the farm effect on asthma could be explained by specific farm characteristics, there is a link still missing for hay fever and atopy.
Asunto(s)
Asma/epidemiología , Asma/prevención & control , Exposición a Riesgos Ambientales , Hipersensibilidad Inmediata/epidemiología , Hipersensibilidad Inmediata/prevención & control , Agricultura , Animales , Austria , Gatos , Bovinos , Niño , Perros , Alemania , Humanos , Inmunoglobulina E/sangre , Polonia , Aves de Corral , Prevalencia , Población Rural , Ovinos , Encuestas y Cuestionarios , Porcinos , SuizaRESUMEN
BACKGROUND: IgE sensitization against grass pollen is a cause of seasonal allergic rhinitis. OBJECTIVE: We sought to investigate the evolution at the molecular level and the preclinical predictive value of IgE responses against grass pollen. METHODS: The German Multicentre Allergy Study examined a birth cohort born in 1990. A questionnaire was administered yearly, and blood samples were collected at 1, 2, 3, 5, 6, 7, 10, and 13 years of age. Grass pollen-related seasonal allergic rhinitis (SARg) was diagnosed according to nasal symptoms in June/July. Serum IgE antibodies to Phleum pratense extract and 8 P pratense molecules were tested with immune-enzymatic singleplex and multiplex assays, respectively. RESULTS: One hundred seventy-seven of the 820 examined children had SARg. A weak monomolecular/oligomolecular IgE response to P pratense was observed very frequently before SARg onset. These initial IgE responses increased in concentration and molecular complexity during the preclinical and clinical process. A typical progression of IgE sensitization was observed: Phl p 1 (initiator in >75% of cases); then Phl p 4 and Phl p 5; then Phl p 2, Phl p 6, and Phl p 11; and then Phl p 12 and Phl p 7. At age 3 years, IgE sensitization predicted SARg by age 12 years (positive predictive value, 68% [95% CI, 50% to 82%]; negative predictive value, 84% [95% CI, 80% to 87%]). At this preclinical prediction time, the number of recognized molecules and the serum levels of IgE to P pratense were significantly lower than at 3 or more years after SARg onset. CONCLUSIONS: The IgE response against grass pollen molecules can start years before disease onset as a weak monosensitization or oligosensitization phenomenon. It can increase in serum concentration and complexity through a "molecular spreading" process during preclinical and early clinical disease stages. Testing IgE sensitization at a preclinical stage facilitates prediction of seasonal allergic rhinitis at its molecular monosensitization or oligosensitization stage.
Asunto(s)
Inmunoglobulina E/sangre , Phleum/inmunología , Rinitis Alérgica Estacional/inmunología , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Lactante , Masculino , Valor Predictivo de las Pruebas , Estudios ProspectivosRESUMEN
Mechanisms of the Development of Allergy (MeDALL), a Seventh Framework Program European Union project, aims to generate novel knowledge on the mechanisms of initiation of allergy. Precise phenotypes of IgE-mediated allergic diseases will be defined in MeDALL. As part of MeDALL, a scientific seminar was held on January 24, 2011, to review current knowledge on the IgE-related phenotypes and to explore how a multidisciplinary effort could result in a new integrative translational approach. This article provides a summary of the meeting. It develops challenges in IgE-related phenotypes and new clinical and epidemiologic approaches to the investigation of allergic phenotypes, including cluster analysis, scale-free models, candidate biomarkers, and IgE microarrays; the particular case of severe asthma was reviewed. Then novel approaches to the IgE-associated phenotypes are reviewed from the individual mechanisms to the systems, including epigenetics, human in vitro immunology, systems biology, and animal models. The last chapter deals with the understanding of the population-based IgE-associated phenotypes in children and adolescents, including age effect in terms of maturation, observed effects of early-life exposures and shift of focus from early life to pregnancy, gene-environment interactions, cohort effects, and time trends in patients with allergic diseases. This review helps to define phenotypes of allergic diseases in MeDALL.
Asunto(s)
Hipersensibilidad/inmunología , Inmunoglobulina E/inmunología , Fenotipo , Adolescente , Animales , Niño , Preescolar , Epigénesis Genética , Humanos , Hipersensibilidad/epidemiología , Hipersensibilidad/genética , Investigación , Factores de Riesgo , Adulto JovenRESUMEN
BACKGROUND: An important window of opportunity for early-life exposures has been proposed for the development of atopic eczema and asthma. OBJECTIVE: However, it is unknown whether hay fever with a peak incidence around late school age to adolescence is similarly determined very early in life. METHODS: In the Protection against Allergy-Study in Rural Environments (PASTURE) birth cohort potentially relevant exposures such as farm milk consumption and exposure to animal sheds were assessed at multiple time points from infancy to age 10.5 years and classified by repeated measure latent class analyses (n = 769). Fecal samples at ages 2 and 12 months were sequenced by 16S rRNA. Hay fever was defined by parent-reported symptoms and/or physician's diagnosis of hay fever in the last 12 months using questionnaires at 10.5 years. RESULTS: Farm children had half the risk of hay fever at 10.5 years (adjusted odds ratio [aOR] 0.50; 95% CI 0.31-0.79) than that of nonfarm children. Whereas early life events such as gut microbiome richness at 12 months (aOR 0.66; 95% CI 0.46-0.96) and exposure to animal sheds in the first 3 years of life (aOR 0.26; 95% CI 0.06-1.15) were determinants of hay fever, the continuous consumption of farm milk from infancy up to school age was necessary to exert the protective effect (aOR 0.35; 95% CI 0.17-0.72). CONCLUSIONS: While early life events determine the risk of subsequent hay fever, continuous exposure is necessary to achieve protection. These findings argue against the notion that only early life exposures set long-lasting trajectories.