Background Atopic dermatitis (AD) is a common inflammatory skin disease. Previous studies have revealed shared genetic determinants among different inflammatory disorders, suggesting that markers ...associated with immune-related traits might also play a role in AD. Objective We sought to identify novel genetic risk factors for AD. Methods We examined the results of all genome-wide association studies from a public repository and selected 318 genetic markers that were significantly associated with any inflammatory trait. These markers were considered candidates and tested for association with AD in a 3-step approach including 7 study populations with 7130 patients with AD and 9253 control subjects. Results A functional amino acid change in the IL-6 receptor (IL-6R Asp358Ala; rs2228145) was significantly associated with AD (odds ratio OR, 1.15; P = 5 × 10−9 ). Interestingly, investigation of 2 independent population-based birth cohorts showed that IL-6R 358Ala specifically predisposes to the persistent form of AD (ORpersistent AD = 1.22, P = .0008; ORtransient AD = 1.04, P = .54). This variant determines the balance between the classical membrane-bound versus soluble IL-6R signaling pathways. Carriers of 358Ala had increased serum levels of soluble IL-6R ( P = 4 × 10−14 ), with homozygote carriers showing a 2-fold increase. Moreover, we demonstrate that soluble IL-6R levels were higher in patients with AD than in control subjects (46.0 vs 37.8 ng/mL, P = .001). Additional AD risk variants were identified in RAD50 , RUNX3 , and ERBB3. Conclusion Our study supports the importance of genetic variants influencing inflammation in the etiology of AD. Moreover, we identified a functional genetic variant in IL6R influencing disease prognosis and specifically predisposing to persistent AD.
Background Health care-associated infections (HAIs) cause considerable morbidity and mortality to hospitalized patients. The objective of this point prevalence study was to assess the burden of HAIs ...in the Canadian pediatric population, updating results reported from a similar study conducted in 2002. Methods A point prevalence survey of pediatric inpatients was conducted in February 2009 in 30 pediatric or combined adult/pediatric hospitals. Data pertaining to one 24-hour period were collected, including information on HAIs, microorganisms isolated, antimicrobials prescribed, and use of additional (transmission based) precautions. The following prevalent infections were included: pneumonia, urinary tract infection, bloodstream infection, surgical site infection, viral respiratory infection, Clostridium difficile infection, viral gastroenteritis, and necrotizing enterocolitis. Results One hundred eighteen patients had 1 or more HAI, corresponding to a prevalence of 8.7% (n = 118 of 1353, 95% confidence interval: 7.2-10.2). Six patients had 2 infections. Bloodstream infections were the most frequent infection in neonates (3.0%), infants (3.1%), and children (3.5%). Among all patients surveyed, 16.3% were on additional precautions, and 40.1% were on antimicrobial agents, whereas 40.7% of patients with a HAI were on additional precautions, and 89.0% were on antimicrobial agents. Conclusion Overall prevalence of HAI in 2009 has remained similar to the prevalence reported from 2002. The unchanged prevalence of these infections nonetheless warrants continued vigilance on their prevention and control.
Purpose We examined symptom variability in men and women with urological chronic pelvic pain syndrome. We describe symptom fluctuations as related to early symptom regression and its effect on ...estimated 1-year symptom change. We also describe a method to quantify patient specific symptom variability. Materials and Methods Symptoms were assessed biweekly in 424 subjects with urological chronic pelvic pain syndrome during 1 year. To evaluate the impact of early symptom regression subjects were classified as improved, no change or worse according to the rate of change using 1) all data, 2) excluding week 0 and 3) excluding weeks 0 and 2. Patient specific, time varying variability was calculated at each interval using a sliding window approach. Patients were classified as high, medium or low variability at each time and ultimately as high or low variability overall based on the variability for the majority of contacts. Results Prior to excluding early weeks to adjust for early symptom regression 25% to 38% and 5% to 6% of patients were classified as improved and worse, respectively. After adjustment the percent of patients who were improved or worse ranged from 15% to 25% and 6% to 9%, respectively. High and low variability phenotypes were each identified in 25% to 30% of participants. Conclusions Patients with urological chronic pelvic pain syndrome show symptom variability. At study enrollment patients had worse symptoms on average, resulting in a regression effect that influenced the estimated proportion of those who were improved or worse. Prospective studies should include a run-in period to account for regression to the mean and other causes of early symptom regression. Further, symptom variability may be quantified and used to characterize longitudinal symptom profiles of urological chronic pelvic pain syndrome.
Background IgE-mediated peanut allergy is a complex trait with strong heritability, but its genetic basis is currently unknown. Loss-of-function mutations within the filaggrin gene are associated ...with atopic dermatitis and other atopic diseases; therefore, filaggrin is a candidate gene in the etiology of peanut allergy. Objective To investigate the association between filaggrin loss-of-function mutations and peanut allergy. Methods Case-control study of 71 English, Dutch, and Irish oral food challenge–positive patients with peanut allergy and 1000 non peanut-sensitized English population controls. Replication was tested in 390 white Canadian patients with peanut allergy (defined by food challenge, or clinical history and skin prick test wheal to peanut ≥8 mm and/or peanut-specific IgE ≥15 kUL−1 ) and 891 white Canadian population controls. The most prevalent filaggrin loss-of-function mutations were assayed in each population: R501X and 2282del4 in the Europeans, and R501X, 2282del4, R2447X, and S3247X in the Canadians. The Fisher exact test and logistic regression were used to test for association; covariate analysis controlled for coexistent atopic dermatitis. Results Filaggrin loss-of-function mutations showed a strong and significant association with peanut allergy in the food challenge–positive patients ( P = 3.0 × 10−6 ; odds ratio, 5.3; 95% CI, 2.8-10.2), and this association was replicated in the Canadian study ( P = 5.4 × 10−5 ; odds ratio, 1.9; 95% CI, 1.4-2.6). The association of filaggrin mutations with peanut allergy remains significant ( P = .0008) after controlling for coexistent atopic dermatitis. Conclusion Filaggrin mutations represent a significant risk factor for IgE-mediated peanut allergy, indicating a role for epithelial barrier dysfunction in the pathogenesis of this disease.
Background Genome-wide association studies identified IL33 and IL-1 receptor–like 1 ( IL1RL1 )/ IL18R1 as asthma susceptibility loci. IL33 and IL1RL1 constitute a single ligand-receptor pathway. ...Objective In 2 birth cohorts, the Prevalence and Incidence of Asthma and Mite Allergy (PIAMA) study and Avon Longitudinal Study of Parents and Children (ALSPAC), we analyzed associations of longitudinal wheezing phenotypes and asthma with single nucleotide polymorphisms (SNPs) of 8 genes encoding IL-33, IL1RL1, its coreceptor IL1RAcP, its adaptors myeloid differentiation primary response gene 88 (MyD88) and Toll–IL-11 receptor domain containing adaptor protein (TIRAP), and the downstream IL-1 receptor–associated kinase 1, IL-1 receptor–associated kinase 4, and TNF receptor–associated factor 6 (TRAF6). Furthermore, we investigated whether SNPs in this pathway show replicable evidence of gene-gene interaction. Methods Ninety-four SNPs were investigated in 2007 children in the PIAMA study and 7247 children in ALSPAC. Associations with wheezing phenotypes and asthma at 8 years of age were analyzed in each cohort and subsequently meta-analyzed. Gene-gene interactions were assessed through model-based multifactor dimensionality reduction in the PIAMA study, and gene-gene interactions of 10 SNP pairs were further evaluated. Results Intermediate-onset wheeze was associated with SNPs in several genes in the IL33-IL1RL1 pathway after applying multiple testing correction in the meta-analysis: 2 IL33 SNPs (rs4742170 and rs7037276), 1 IL-1 receptor accessory protein (IL1RAP) SNP (rs10513854), and 1 TRAF6 SNP (rs5030411). Late-onset wheeze was associated with 2 IL1RL1 SNPs (rs10208293 and rs13424006), and persistent wheeze was associated with 1 IL33 SNP (rs1342326) and 1 IL1RAP SNP (rs9290936). IL33 and IL1RL1 SNPs were nominally associated with asthma. Three SNP pairs showed interaction for asthma in the PIAMA study but not in ALSPAC. Conclusions IL33-IL1RL1 pathway polymorphisms are associated with asthma and specific wheezing phenotypes; that is, most SNPs are associated with intermediate-onset wheeze, a phenotype closely associated with sensitization. We speculate that IL33-IL1RL1 pathway polymorphisms affect development of wheeze and subsequent asthma through sensitization in early childhood.
Background Asthma has its origins in early childhood, but different patterns of childhood wheezing vary in their associations with subsequent asthma, atopy, and bronchial hyperresponsiveness (BHR). ...Novel wheezing phenotypes have been identified on the basis of analyses of longitudinal data from the Avon Longitudinal Study of Parents And Children (ALSPAC). It is unclear whether these phenotypes can be replicated in other birth cohorts. Objective To compare wheezing phenotypes identified in the first 8 years of life in the ALSPAC study and the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) study. Methods We used longitudinal latent class analysis to identify phenotypes on the basis of repeated reports of wheezing from 0 to 8 years in 5760 children from the ALSPAC study and 2810 children from the PIAMA study. Phenotypes were compared between cohorts. Associations with asthma, atopy, BHR, and lung function were analyzed by using weighted regression analyses. Results The model with the best fit to PIAMA data in the first 8 years of life was a 5-class model. Phenotypes identified in the PIAMA study had wheezing patterns that were similar to those previously reported in ALSPAC, adding further evidence to the existence of an intermediate-onset phenotype with onset of wheeze after 2 years of age. Associations with asthma, atopy, BHR, and lung function were remarkably similar in the 2 cohorts. Conclusion Wheezing phenotypes identified by using longitudinal latent class analysis were comparable in 2 large birth cohorts. Study of genetic and environmental factors associated with different phenotypes may help elucidate the origins of asthma.
Background Variable patterns of childhood wheezing might indicate differences in the cause and prognosis of respiratory illnesses. Better understanding of these patterns could facilitate ...identification of modifiable factors related to development of asthma. Objectives We characterized childhood wheezing phenotypes from infancy to adolescence and their associations with asthma outcomes. Methods Latent class analysis was used to derive phenotypes based on patterns of wheezing recorded at up to 14 time points from birth to 16½ years among 12,303 participants from the Avon Longitudinal Study of Parents and Children. Measures of lung function (FEV1 , forced vital capacity FVC, and forced expiratory flow between 25% and 75% FEF25-75 ) and fraction of exhaled nitric oxide (F eno ) were made at 14 to 15 years of age. Results Six wheezing phenotypes were identified: never/infrequent, preschool-onset remitting, midchildhood-onset remitting, school age–onset persisting, late childhood–onset persisting, and continuous wheeze. The 3 persistent phenotypes were associated with bronchodilator reversibility of 12% or greater (BDR) from baseline (odds ratio OR range, 2.14-3.34), a F eno value of 35 ppb or greater (OR range, 3.82-6.24), and lung function decrements (mean range of differences: −0.22 to −0.27 SD units (SDU) for FEV1 /FVC ratio and −0.21 to −0.33 SDU for FEF25-75 ) compared with never/infrequent wheeze. Midchildhood-onset (4½ years) remitting wheeze was associated with BDR (OR, 1.77; 95% CI, 1.11-2.82), a F eno value of 35 ppb or greater (OR, 1.72; 95% CI, 1.14-2.59), FEV1 /FVC ratio decrements (OR, −0.22 SDU; 95% CI, −0.36 to −0.08 SDU), and FEF25-75 decrements (OR, −0.16 SDU; 95% CI, −0.30 to −0.01 SDU). Preschool-onset (18 months) remitting wheeze was only associated with FEV1 /FVC ratio decrements (OR, −0.15 SDU; 95% CI, −0.25 to −0.05 SDU) and FEF25-75 decrements (OR, −0.14 SDU; 95% CI, −0.24 to −0.04 SDU). The persisting phenotypes showed evidence of sex stratification during adolescence. Conclusions Early childhood–onset wheezing that persists into adolescence represents the clearest target group for interventions to maximize lung function outcomes.
Background The relationship between allergy and autoimmune disorders is complex and poorly understood. Objective We sought to investigate commonalities in genetic loci and pathways between allergy ...and autoimmune diseases to elucidate shared disease mechanisms. Methods We meta-analyzed 2 genome-wide association studies on self-reported allergy and sensitization comprising a total of 62,330 subjects. These results were used to calculate enrichment for single nucleotide polymorphisms (SNPs) previously associated with autoimmune diseases. Furthermore, we probed for enrichment within genetic pathways and of transcription factor binding sites and characterized commonalities in variant burden on tissue-specific regulatory sites by calculating the enrichment of allergy SNPs falling in gene regulatory regions in various cells using Encode Roadmap DNase-hypersensitive site data. Finally, we compared the allergy data with those of all known diseases. Results Among 290 loci previously associated with 16 autoimmune diseases, we found a significant enrichment of loci also associated with allergy ( P = 1.4e-17) encompassing 29 loci at a false discovery rate of less than 0.05. Such enrichment seemed to be a general characteristic for autoimmune diseases. Among the common loci, 48% had the same direction of effect for allergy and autoimmune diseases. Additionally, we observed an enrichment of allergy SNPs falling within immune pathways and regions of chromatin accessible in immune cells that was also represented in patients with autoimmune diseases but not those with other diseases. Conclusion We identified shared susceptibility loci and commonalities in pathways between allergy and autoimmune diseases, suggesting shared disease mechanisms. Further studies of these shared genetic mechanisms might help in understanding the complex relationship between these diseases, including the parallel increase in disease prevalence.
Disaggregating asthma: Big investigation versus big data Belgrave, Danielle, PhD; Henderson, John, MD; Simpson, Angela, MD, PhD ...
Journal of allergy and clinical immunology,
02/2017, Letnik:
139, Številka:
2
Journal Article
Recenzirano
Odprti dostop
We are facing a major challenge in bridging the gap between identifying subtypes of asthma to understand causal mechanisms and translating this knowledge into personalized prevention and management ...strategies. In recent years, “big data” has been sold as a panacea for generating hypotheses and driving new frontiers of health care; the idea that the data must and will speak for themselves is fast becoming a new dogma. One of the dangers of ready accessibility of health care data and computational tools for data analysis is that the process of data mining can become uncoupled from the scientific process of clinical interpretation, understanding the provenance of the data, and external validation. Although advances in computational methods can be valuable for using unexpected structure in data to generate hypotheses, there remains a need for testing hypotheses and interpreting results with scientific rigor. We argue for combining data- and hypothesis-driven methods in a careful synergy, and the importance of carefully characterized birth and patient cohorts with genetic, phenotypic, biological, and molecular data in this process cannot be overemphasized. The main challenge on the road ahead is to harness bigger health care data in ways that produce meaningful clinical interpretation and to translate this into better diagnoses and properly personalized prevention and treatment plans. There is a pressing need for cross-disciplinary research with an integrative approach to data science, whereby basic scientists, clinicians, data analysts, and epidemiologists work together to understand the heterogeneity of asthma.
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