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Environmentally-Induced Epigenetic Changes Correlate with Race and Childhood Asthma Severity
Abstracts AB391
J ALLERGY CLIN IMMUNOL VOLUME 137, NUMBER 2
L7
Role of Home Environmental Staphylococcus Aureus Bacterial Allergens in Childhood Asthma
Dr Meghan F. Davis, DVM, MPH, PhD1, Dr. Shanna Ludwig, PhD2, Dr Emily Brigham, MD3, Dr Meredith C. McCormack, MD4, Elizabeth Matsui, MD, MHS5; 1Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 2Johns Hopkins School of Public Health, Baltimore, MD, 3 The Johns Hopkins University School of Medicine, Baltimore, MD, 4The Johns Hopkins Pulmonary, Baltimore, MD, 5Division of Pediatric Allergy/ Immunology, Johns Hopkins School of Medicine, Baltimore, MD. RATIONALE: Staphylococcus aureus (SA) may induce allergic (Th2-biased) inflammatory responses through secreted staphylococcal enterotoxin (SE) A-D superantigens. SA is known to exacerbate eczema and increasingly is implicated in asthma exacerbations. We quantified putative staphylococcal allergens in home dust using a bacterial genetic method, then we associated SA/SE exposures with respiratory symptoms among children with asthma. METHODS: We measured SA (femB) and SEA-D genes in home dust extracts from the randomization visit (before treatment) in the completed Asthma Control Evaluation cohort (NCT00114413) using real-time PCR. We tested cross-sectional associations between dust exposures and self-reported respiratory symptoms in 245 inner-city children with asthma (;50% of the cohort) using linear and binomial regression modeling. RESULTS: We identified SA genes in 189 (77%) of 245 homes, with prevalence of any SE gene detection as follows: SEA (60%); SEB (52%); SEC (51%); SED (63%). Among children with asthma, mean ACT score was 20.7 and mean days of symptoms in the prior two weeks were: wheeze/ cough: 2.2; interference with activities: 1.2; sleep disruption: 0.6. Strong _35, was associated with worse dust SEA detection, i.e. threshold cycle (Ct)< ACT score [b5-1.46, p50.01] and increased odds of having a symptom day for each of the two-week outcomes, e.g. [wheeze/cough OR 1.55, p<0.001]. SA and SEB-SED were variably associated or were not associated with respiratory symptom outcomes. CONCLUSIONS: Home staphylococcal dust exposures (SA/SE) were common among inner-city children with asthma. Dust SEA detection consistently was associated with increased respiratory symptoms in this cohort. Longitudinal studies are needed to confirm and explicate this novel finding.
L8
Environmentally-Induced Epigenetic Changes Correlate with Race and Childhood Asthma Severity
Dr. Marcia A. Chan, PhD1, Dr Christina E. Ciaccio, MD, MSc, FAAAAI2, Nicole M. Gigliotti, BS1, Mo Rezaiekhaligh, MS1, Jacob A. Siedlik, MA3, Kevin Kennedy, MPH, CIEC1, Dr Charles S. Barnes, PhD1; 1Children’s Mercy Hospital, Kansas City, MO, 2University of Chicago, 3University of Kansas, Lawrence, KS. RATIONALE: Socioeconomic status, genetic predisposition and environmental factors contribute to asthma incidence and severity. Children with asthma who are economically disadvantaged likely live in substandard housing with potential indoor environmental exposures that may manifest through epigenetic mechanisms. We examined the association of global DNA methylation with socioeconomic status, asthma severity and race/ethnicity. METHODS: Global DNA methylation was measured in peripheral blood of children with asthma between the ages of 2 and 17 yrs enrolled in the Kansas City Safe and Healthy Homes Program. Inclusion criteria included residing in the same home for a minimum of 4 days per week and total family income of less than 80% of the Kansas City median family income (MFI). A three-way mixed factorial ANOVA was used to analyze global DNA methylation. When appropriate, follow-up analyses were performed using independent-samples ttests and ANOVA models with Bonferroni corrections. RESULTS: Our results indicate that overall, African American children with asthma had significantly higher levels of global DNA methylation than children with asthma of other races/ethnicities (p 5 0.029). This
difference was more pronounced when socioeconomic status and asthma severity were considered (p 5 0.042). In children with persistent asthma from the lowest income families (<50% Kansas City MFI), significantly higher levels of global DNA methylation were observed in African American children compared to children of other races/ethnicities (p 5 0.05). CONCLUSION: Our study demonstrates a significant interaction effect among global DNA methylation levels with asthma severity, race/ethnicity, and socioeconomic status.
L9
Withdrawn
J ALLERGY CLIN IMMUNOL VOLUME 137, NUMBER 2
L7
Role of Home Environmental Staphylococcus Aureus Bacterial Allergens in Childhood Asthma
Dr Meghan F. Davis, DVM, MPH, PhD1, Dr. Shanna Ludwig, PhD2, Dr Emily Brigham, MD3, Dr Meredith C. McCormack, MD4, Elizabeth Matsui, MD, MHS5; 1Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 2Johns Hopkins School of Public Health, Baltimore, MD, 3 The Johns Hopkins University School of Medicine, Baltimore, MD, 4The Johns Hopkins Pulmonary, Baltimore, MD, 5Division of Pediatric Allergy/ Immunology, Johns Hopkins School of Medicine, Baltimore, MD. RATIONALE: Staphylococcus aureus (SA) may induce allergic (Th2-biased) inflammatory responses through secreted staphylococcal enterotoxin (SE) A-D superantigens. SA is known to exacerbate eczema and increasingly is implicated in asthma exacerbations. We quantified putative staphylococcal allergens in home dust using a bacterial genetic method, then we associated SA/SE exposures with respiratory symptoms among children with asthma. METHODS: We measured SA (femB) and SEA-D genes in home dust extracts from the randomization visit (before treatment) in the completed Asthma Control Evaluation cohort (NCT00114413) using real-time PCR. We tested cross-sectional associations between dust exposures and self-reported respiratory symptoms in 245 inner-city children with asthma (;50% of the cohort) using linear and binomial regression modeling. RESULTS: We identified SA genes in 189 (77%) of 245 homes, with prevalence of any SE gene detection as follows: SEA (60%); SEB (52%); SEC (51%); SED (63%). Among children with asthma, mean ACT score was 20.7 and mean days of symptoms in the prior two weeks were: wheeze/ cough: 2.2; interference with activities: 1.2; sleep disruption: 0.6. Strong _35, was associated with worse dust SEA detection, i.e. threshold cycle (Ct)< ACT score [b5-1.46, p50.01] and increased odds of having a symptom day for each of the two-week outcomes, e.g. [wheeze/cough OR 1.55, p<0.001]. SA and SEB-SED were variably associated or were not associated with respiratory symptom outcomes. CONCLUSIONS: Home staphylococcal dust exposures (SA/SE) were common among inner-city children with asthma. Dust SEA detection consistently was associated with increased respiratory symptoms in this cohort. Longitudinal studies are needed to confirm and explicate this novel finding.
L8
Environmentally-Induced Epigenetic Changes Correlate with Race and Childhood Asthma Severity
Dr. Marcia A. Chan, PhD1, Dr Christina E. Ciaccio, MD, MSc, FAAAAI2, Nicole M. Gigliotti, BS1, Mo Rezaiekhaligh, MS1, Jacob A. Siedlik, MA3, Kevin Kennedy, MPH, CIEC1, Dr Charles S. Barnes, PhD1; 1Children’s Mercy Hospital, Kansas City, MO, 2University of Chicago, 3University of Kansas, Lawrence, KS. RATIONALE: Socioeconomic status, genetic predisposition and environmental factors contribute to asthma incidence and severity. Children with asthma who are economically disadvantaged likely live in substandard housing with potential indoor environmental exposures that may manifest through epigenetic mechanisms. We examined the association of global DNA methylation with socioeconomic status, asthma severity and race/ethnicity. METHODS: Global DNA methylation was measured in peripheral blood of children with asthma between the ages of 2 and 17 yrs enrolled in the Kansas City Safe and Healthy Homes Program. Inclusion criteria included residing in the same home for a minimum of 4 days per week and total family income of less than 80% of the Kansas City median family income (MFI). A three-way mixed factorial ANOVA was used to analyze global DNA methylation. When appropriate, follow-up analyses were performed using independent-samples ttests and ANOVA models with Bonferroni corrections. RESULTS: Our results indicate that overall, African American children with asthma had significantly higher levels of global DNA methylation than children with asthma of other races/ethnicities (p 5 0.029). This
difference was more pronounced when socioeconomic status and asthma severity were considered (p 5 0.042). In children with persistent asthma from the lowest income families (<50% Kansas City MFI), significantly higher levels of global DNA methylation were observed in African American children compared to children of other races/ethnicities (p 5 0.05). CONCLUSION: Our study demonstrates a significant interaction effect among global DNA methylation levels with asthma severity, race/ethnicity, and socioeconomic status.
L9
Withdrawn