Dennis R Ownby

Georgia Regents University, Augusta, Georgia, United States

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Publications (235)1369.89 Total impact

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    ABSTRACT: Asthma prevalence has doubled in developed countries during the past 30 years. Pre- and perinatal events are essential in shaping the development of the immune system and systemic antibiotic use during this time could alter the maternal or placental microbiome, leading to an increase in the child's risk of developing asthma. To determine whether prenatal antibiotic use is associated with asthma and wheezing in children at risk for asthma. Using data from a randomized education intervention of families at risk for asthma from 1998 followed through 2009 in urban Chicago, asthma was defined as ever having a physician asthma diagnosis by year 3 and wheezing in the third year. Logistic regression models controlling for confounders investigated the effect of antibiotic use during pregnancy on these outcomes. After adjustment, prenatal antibiotic use was a risk factor for asthma (odds ratio 3.1, 95% confidence interval 1.4-6.8) but was only weakly associated with wheezing (odds ratio 1.8, 95% confidence interval 0.9-3.3). Analyses of the effects of timing of prenatal antibiotic use on asthma and wheezing showed the relation remained consistent for antibiotic use later in pregnancy, but the outcomes were not associated with antibiotic use in the first trimester. This study suggests prenatal antibiotic use might be associated with the development of asthma in children at risk for asthma. Although the relation with prenatal antibiotics does not hold for wheezing in this study, there might be a trend that could be delineated further within a larger cohort study. Copyright © 2014 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
    Annals of allergy, asthma & immunology: official publication of the American College of Allergy, Asthma, & Immunology 12/2014; · 2.75 Impact Factor
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    ABSTRACT: Separately, prenatal antibiotics and cesarian delivery have been found to be associated with increased risk of allergic diseases. It is not clear if these factors may modify the effect of each other. Assess whether the associations between delivery types and eczema, sensitization and total IgE at age 2 years were modified by maternal use of prenatal medications. Prenatal charts of women enrolled in the WHEALS birth cohort were reviewed for delivery mode and medications prescribed and administered throughout their entire pregnancy, including systemic antibiotics and vaginally applied antifungal medications. The associations between the delivery mode and select medications and eczema, sensitization (≥1 of 10 allergen specific IgE ≥0.35 IU/ml) and total IgE at age 2 years were assessed. There was a lower risk of eczema among vaginally versus c-section born children (relative risk adjusted for race=aRR=0.77., 95% CI 0.56, 1.05). Although not statistically significantly different, this association was stronger among the subset of children born vaginally to a mother who did not use systemic antibiotics or vaginal antifungal medications (aRR=0.69, 95% CI 0.44, 1.08) compared to those born vaginally to mothers who used systemic antibiotics or vaginal antifungals (aRR=0.81, 95% CI 0.57, 1.14). A protective association between vaginal birth and sensitization (aRR=0.86, 95% CI 0.72, 1.03) was similar for those children born vaginally to a mother who did not (aRR=0.87, 95% CI 0.69, 1.10) and who did (RR=0.85, 95% CI 0.70, 1.04) use systemic antibiotics or vaginal antifungal medications. There were no associations with total IgE. Children born vaginally had lower risk of eczema and sensitization compared with those born via c-section; however, the protective association with eczema may be slightly weakened when mothers took systemic antibiotics or vaginally applied medications during pregnancy. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Clinical & Experimental Allergy 12/2014; · 4.32 Impact Factor
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    ABSTRACT: Caesarean-section (CS) delivery increases risk of childhood obesity, and is associated with a distinct early-life gut microbiome, which may contribute to obesity. Household pets may alter human gut microbiome composition. We examined if pet-keeping modified the association of CS with obesity at age 2 years in 639 Wayne County Health, Environment, Allergy and Asthma Longitudinal Study birth cohort participants. Pet-keeping was defined as having a dog or cat (indoors ≥1 h/day) at child age 2 years. We used logistic regression to test for an interaction between CS and pet-keeping with obesity (BMI ≥ 95th percentile) at age 2 years, adjusted for maternal obesity. A total of 328 (51.3 %) children were male; 367 (57.4 %) were African American; 228 (35.7 %) were born by CS; and 55 (8.6 %) were obese. After adjusting for maternal obesity, CS-born children had a non-significant (P = 0.25) but elevated 1.4 (95 % CI 0.8, 2.5) higher odds of obesity compared to those born vaginally. There was evidence of effect modification between current pet-keeping and delivery mode with obesity at age 2 years (interaction P = 0.054). Compared to children born vaginally without a pet currently in the home, children born via CS without a pet currently in the home had a statistically significant (P = 0.043) higher odds (odds ratio 2.00; 95 % CI 1.02, 3.93) of being obese at age 2 years. Pets modified the CS-BMI relationship; whether the underlying mechanism is through effects on environmental or gut microbiome requires specific investigation.
    Maternal and Child Health Journal 11/2014; · 2.24 Impact Factor
  • Journal of Allergy and Clinical Immunology 11/2014; 134(5):1189-90. · 11.25 Impact Factor
  • Dennis R. Ownby
    Journal of Allergy and Clinical Immunology 09/2014; · 11.25 Impact Factor
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    ABSTRACT: Background Atopic sensitization (ie, atopy) is the most commonly reported risk factor for asthma. Recent studies have begun to suggest that atopy, as conventionally defined, might be an umbrella term that obfuscates more specific allergic disease types. Objective We sought to determine whether distinct and meaningful atopic phenotypes exist within a racially diverse birth cohort using 10 allergen-specific serum IgE (sIgE) measurements from children aged 2 years. Methods Using the Wayne County Health, Environment, Allergy and Asthma Longitudinal Study (WHEALS) birth cohort (62% black), we analyzed sIgE data on 10 allergens (Dermatophagoides farinae, dog, cat, timothy grass, ragweed, Alternaria alternata, egg, peanut, milk, and German cockroach) obtained from 594 children at age 2 years. Conventional atopy was defined as at least 1 sIgE level of 0.35 IU/mL or greater. Results A 4-class solution (latent class model) was the best fit. Class types were labeled “low to no sensitization” (76.9% of sample), “highly sensitized” (2.7%), “milk and egg dominated” (15.3%), and “peanut and inhalant(s)” (5.1%). Almost one third (32.2%) of the low to no sensitization group met the criteria for conventional atopy. The highly sensitized group was significantly associated with a doctor's diagnosis of asthma after age 4 years (odds ratio [OR], 5.3; 95% CI, 1.6-17.4), whereas the milk and egg dominated and peanut and inhalant(s) groups were not (ORs of 1.6 [95% CI, 0.8-3.0] and 1.8 [95% CI, 0.6-4.9], respectively). Children of black race were more likely to be in the 3 multisensitized groups (P = .04). Conclusion Classification by sIgE patterns defined groups whose membership is more strongly associated with atopic dermatitis, wheeze, and asthma compared with conventional atopy.
    The Journal of allergy and clinical immunology 09/2014; · 12.05 Impact Factor
  • Annals of Epidemiology 07/2014; · 2.15 Impact Factor
  • Journal of Allergy and Clinical Immunology 06/2014; · 11.25 Impact Factor
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    ABSTRACT: Recent research has emphasized the need to better discriminate asthma phenotypes and consider underlying mechanistic endotypes in epidemiologic and clinical studies. Although allergic asthma and nonallergic asthma are frequently combined into 1 disease category in observational research and clinical trials, few studies have investigated the extent to which these 2 separate phenotypes are associated with distinct cytokine immunologic profiles in a representative young adult population. To investigate the cytokine production-based endotypes underlying the clinical phenotypes of allergic and nonallergic asthma in a population-based birth cohort evaluated as young adults. Participants included 18- to 21-year-old members (n = 540) of a suburban Detroit birth cohort study, the Childhood Allergy Study. Phorbol myristate acetate-stimulated whole blood interleukin (IL)-4, IL-5, IL-10, IL-12, IL-13, IL-17A, IL-17F, IL-22, and interferon-γ secretory responses were analyzed for associations comparing participants with allergic vs nonallergic asthma phenotypes with those without asthma. T-helper cell type (TH) 2-polarized responses, measured as higher mean IL-5 and IL-13 secretions and lower ratios of interferon-γ and IL-12 to 3 TH2 cytokines (IL-4, IL-5, or IL-13), were observed only in participants with allergic asthma. Nonallergic asthma was associated with TH1-polarized responses, including higher adjusted interferon-γ secretion compared with participants with allergic asthma and, surprisingly, those without asthma (odds ratio 2.5, confidence interval 1.2-5.1, P < .01). As expected, young adults with a history of an allergic asthma phenotype exhibited a TH2-polarized cytokine response after polyclonal stimulation. However, TH1 polarization was observed in patients with a history of nonallergic asthma. Allergic and nonallergic asthma are associated with etiologically distinct immune endotypes, underscoring the importance of discriminating these endotypes in research analyses and clinical management.
    Annals of allergy, asthma & immunology: official publication of the American College of Allergy, Asthma, & Immunology 05/2014; · 2.75 Impact Factor
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    ABSTRACT: Population-based birth cohorts on asthma and allergies increasingly provide new insights into the development and natural history of the diseases. More than 130 birth cohorts focusing on asthma and allergy have been initiated in the last 30 years. A National Institute of Allergy and Infectious Diseases; National Heart, Lung, and Blood Institute; Mechanisms of the Development of Allergy (MeDALL; Framework Programme 7 of the European Commission) joint workshop was held in Bethesda, Maryland, on September 11-12, 2012, with 3 objectives: (1) documenting the knowledge that asthma/allergy birth cohorts have provided, (2) identifying the knowledge gaps and inconsistencies, and (3) developing strategies for moving forward, including potential new study designs and the harmonization of existing asthma birth cohort data. The meeting was organized around the presentations of 5 distinct workgroups: (1) clinical phenotypes, (2) risk factors, (3) immune development of asthma and allergy, (4) pulmonary development, and (5) harmonization of existing birth cohorts. This article presents the workgroup reports and provides Web links (AsthmaBirthCohorts.niaid.nih.gov or www.medall-fp7.eu), where the reader will find tables describing the characteristics of the birth cohorts included in this report, the type of data collected at differing ages, and a selected bibliography provided by the participating birth cohorts.
    The Journal of allergy and clinical immunology 03/2014; · 12.05 Impact Factor
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    ABSTRACT: Clinical trials are critical for medical decision-making, however, under the current paradigm, clinical trials are fraught with problems including low enrollment and high cost. Promising alternatives to increase trial efficiency and reduce costs include the use of (1) electronic initiatives that permit electronic remote data capture (EDC) for direct data collection at a site (2), electronic medical records (EMR) for patient identification and data collection, and (3) adaptive, enrichment designs with pragmatic approaches. We describe the design of a seamless, multi-site randomized Phase II/III trial to evaluate an asthma management intervention in urban adolescents with asthma. Patients are randomized, asked to access four online sessions of the intervention or control asthma management program, and are then followed for one year. The primary efficacy endpoint is self-reported asthma control as measured by the Asthma Control Test (ACT). Comparative effectiveness parametric approaches are utilized to conduct the trial in a real world setting with reduced costs. Escalated electronic initiatives are implemented for patient identification, assent, enrollment and tracking. Patient enrollment takes place during primary care visits. A centralized database with EDC is used for CRF data collection with integration of EMR data. This Phase II/II trial plans to have a total sample size of 500 patients with an interim look at the completion of Phase II (n=250), The interim analyses include an assessment of the intervention effect, marker(s) identification and the feasibility study of EMR data as the trial CRF data collection. Patient enrollment has begun and is ongoing.
    Contemporary clinical trials 03/2014; · 1.51 Impact Factor
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    ABSTRACT: The infant gut's ability to suppress immunologic reactions to food proteins could be influenced by levels of TGFβ in breast milk. We hypothesized that lower levels of TGFβ1 in the breast milk (BM) of mothers in the WHEALS birth cohort are associated with atopy at infant age 2-3 yrs. We used data collected during infancy in addition to the results of skin prick tests (SPT+) and measures of specific IgE >0.35 IU/ml (spIgE) to milk, egg, and peanut at infant age 2-3 years. Infants were classified as food allergic (FA) based on parental report of infant symptoms/diagnoses and information from clinical assessments. Data for 304 cohort members were analyzed. Among non-black infants, BM-TGFβ1 was lower for those classified as FA (vs. no FA) and those SPT+ (vs., SPT-), geometric mean = 1100 pg/ml vs. 1417pg/ml, p = 0.081; and 1100 pg/ml vs. 1415pg/ml, p = 0.064, respectively. Among infants of non-atopic mothers, BM-TGFβ1 was lower for those with elevated (vs. not elevated) sIgE, geometric mean = 1347 pg/ml vs. 1651 pg/ml, p = 0.047. Using logistic regression, adjusted odds ratios describing the association of BM-TGFβ1 to the presence of atopic indicators in the infant were in the hypothesized direction only for non-black infants of non-atopic mothers: aORs for FA, sIgE and SPT+ were 0.08, 0.34, and 0.26 respectively; p = 0.091, 0.13, and 0.23. Immune benefit of BM-TGFβ1 could inform prevention strategies. Evidence of an association appears greatly influenced by infant race and maternal atopy. More research can determine if these relationships represent a modifiable risk factor for the development of food allergy in certain subgroups.
    Pediatric Allergy and Immunology 02/2014; · 3.38 Impact Factor
  • Journal of Allergy and Clinical Immunology 02/2014; 133(2):AB6. · 11.25 Impact Factor
  • Journal of Allergy and Clinical Immunology 02/2014; 133(2):AB87. · 11.25 Impact Factor
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    ABSTRACT: There is consistent evidence demonstrating that pet-keeping, particularly of dogs, is beneficial to human health. We explored relationships between maternal race and prenatal dog-keeping, accounting for measures of socioeconomic status that could affect the choice of owning a pet, in a demographically diverse, unselected birth cohort. Self-reported data on mothers' race, socioeconomic characteristics and dog-keeping practices were obtained during prenatal interviews and analyzed cross-sectionally. Robust methods of covariate balancing via propensity score analysis were utilized to examine if race (Black vs White), independent of other participant traits, influenced prenatal dog-keeping. A birth cohort study conducted in a health care system in metropolitan Detroit, Michigan between September 2003 and November 2007. 1065 pregnant women (n=775 or 72.8% Black), between ages 21 and 45, receiving prenatal care. Participant's self-report of race/ethnicity and prenatal dog-keeping, which was defined as her owning or caring for > or =1 dog for more than 1 week at her home since learning of her pregnancy, regardless of whether the dog was kept inside or outside of her home. In total, 294 women (27.6%) reported prenatal dog-keeping. Prenatal dog-keeping was significantly lower among Black women as compared to White women (20.9% vs 45.5%, P<.001), and remained significantly different even after propensity score analysis was applied. Findings suggest that there are persistent racial differences in dog-keeping not fully explained by measures of socioeconomic status. Racial differences in prenatal dog-keeping may contribute to childhood health disparities.
    Ethnicity & disease 01/2014; 24(1):104-9. · 0.92 Impact Factor
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    ABSTRACT: Background Recent research has emphasized the need to better discriminate asthma phenotypes and consider underlying mechanistic endotypes in epidemiologic and clinical studies. Although allergic asthma and nonallergic asthma are frequently combined into 1 disease category in observational research and clinical trials, few studies have investigated the extent to which these 2 separate phenotypes are associated with distinct cytokine immunologic profiles in a representative young adult population. Objective To investigate the cytokine production-based endotypes underlying the clinical phenotypes of allergic and nonallergic asthma in a population-based birth cohort evaluated as young adults. Methods Participants included 18- to 21-year-old members (n = 540) of a suburban Detroit birth cohort study, the Childhood Allergy Study. Phorbol myristate acetate–stimulated whole blood interleukin (IL)-4, IL-5, IL-10, IL-12, IL-13, IL-17A, IL-17F, IL-22, and interferon-γ secretory responses were analyzed for associations comparing participants with allergic vs nonallergic asthma phenotypes with those without asthma. Results T-helper cell type (TH) 2-polarized responses, measured as higher mean IL-5 and IL-13 secretions and lower ratios of interferon-γ and IL-12 to 3 TH2 cytokines (IL-4, IL-5, or IL-13), were observed only in participants with allergic asthma. Nonallergic asthma was associated with TH1-polarized responses, including higher adjusted interferon-γ secretion compared with participants with allergic asthma and, surprisingly, those without asthma (odds ratio 2.5, confidence interval 1.2–5.1, P < .01). Conclusion As expected, young adults with a history of an allergic asthma phenotype exhibited a TH2–polarized cytokine response after polyclonal stimulation. However, TH1 polarization was observed in patients with a history of nonallergic asthma. Allergic and nonallergic asthma are associated with etiologically distinct immune endotypes, underscoring the importance of discriminating these endotypes in research analyses and clinical management.
    Annals of Allergy, Asthma & Immunology. 01/2014;
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    ABSTRACT: Exposure to dogs in early infancy has been shown to reduce the risk of childhood allergic disease development, and dog ownership is associated with a distinct house dust microbial exposure. Here, we demonstrate, using murine models, that exposure of mice to dog-associated house dust protects against ovalbumin or cockroach allergen-mediated airway pathology. Protected animals exhibited significant reduction in the total number of airway T cells, down-regulation of Th2-related airway responses, as well as mucin secretion. Following dog-associated dust exposure, the cecal microbiome of protected animals was extensively restructured with significant enrichment of, amongst others, Lactobacillus johnsonii. Supplementation of wild-type animals with L. johnsonii protected them against both airway allergen challenge or infection with respiratory syncytial virus. L. johnsonii-mediated protection was associated with significant reductions in the total number and proportion of activated CD11c(+)/CD11b(+) and CD11c(+)/CD8(+) cells, as well as significantly reduced airway Th2 cytokine expression. Our results reveal that exposure to dog-associated household dust results in protection against airway allergen challenge and a distinct gastrointestinal microbiome composition. Moreover, the study identifies L. johnsonii as a pivotal species within the gastrointestinal tract capable of influencing adaptive immunity at remote mucosal surfaces in a manner that is protective against a variety of respiratory insults.
    Proceedings of the National Academy of Sciences 12/2013; · 9.81 Impact Factor
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    ABSTRACT: It is unknown whether family members with detectable specific immunoglobulin E (sIgE) and/or allergic symptoms to pets are more or less likely to reside in a household with pets. We cross-sectionally investigated potential relationships between family members' allergic sensitization and symptoms to dogs and cats and current household pet-keeping practices, using birth cohort data. Blood samples taken from children enrolled in a birth cohort and their biological mothers and fathers, when the children were aged 18 years, were assessed for sIgE to dog and cat allergens. Interviews assessed subjects' self-reported pet exposure symptoms, current household pet-keeping practices, and socioeconomic characteristics. Overall, household dog or cat keeping was not associated with sIgE to these animals and/or self-reported allergic symptoms in the presence of these animals, even after controlling for factors such as education and household income. In subgroup analyses, current household dog keeping among dog-symptomatic teens (n = 40) was significantly lower than among teens who were not dog symptomatic (n = 289), at 48.8 and 61.1%, respectively (p = 0.036). Current household cat keeping was significantly lower among cat-symptomatic mothers (n = 27) compared with mothers who were not cat symptomatic (n = 120), at 24.3 and 37.0%, respectively (p = 0.015). However, when considering those who were both sensitized and reported symptoms, only the mother and cat-keeping associations persisted (p = 0.049). When cat-sensitized mothers report allergic symptoms to cats, these pets may be less likely to be kept in homes. Elevated dog and cat allergen sIgE does not appear to be associated with the keeping of these pets.
    Allergy and Asthma Proceedings 11/2013; 34(6):504-10. · 3.35 Impact Factor
  • Dennis R Ownby
    The Journal of allergy and clinical immunology 08/2013; · 12.05 Impact Factor
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    ABSTRACT: Background Environmental allergens may induce the generation of allergen-specific IgE (sIgE) and IgG4 (sIgG4). Some studies report an association of sIgG4 to protection against allergic symptoms after exposure to the relevant allergen. Objective We examined the relationship of dog and cat sIgE and sIgG4 levels to self-reported allergic symptoms on pet contact. Methods Participants 18 years of age in the Detroit Childhood Allergy Study cohort were asked whether they experienced symptoms on exposure to cats and dogs. Serum was assayed for cat and dog sIgE and sIgG4. Geometric means, ratios of cat and dog sIgE, sIgG4, and ratios of sIgG4/sIgE were compared between symptomatic and asymptomatic teens with the use of Wilcoxon rank sum tests. Ratios of sIgG4/sIgE, adjusted for presence of sIgE (≥0.35 kU/mL), were analyzed with logistic regression. Results Data on 500 participants were analyzed. Compared with asymptomatic teens, teens symptomatic with cat exposure had higher cat sIgE, sIgG4, and lower ratio of sIgG4/sIgE. Teens symptomatic after dog exposure had higher dog sIgE levels and lower sIgG4/sIgE, but similar levels of sIgG4 compared with asymptomatic participants. Increasing cat and dog sIgG4/sIgE ratios were associated with a lower likelihood of reporting allergic symptoms (cat: adjusted odds ratio, 0.8; 95% CI, 0.6-0.9; dog: adjusted odds ratio, 0.8; 95% CI, 0.7-1.0). Conclusion sIgG4 levels to cat and dog allergens correlate with lower rates of pet-induced allergic symptoms when interpreted in the context of concomitant sIgE. However, sIgG4 appears to have little utility as an isolated marker to indicate that pet exposure will be well tolerated.
    The Journal of Allergy and Clinical Immunology: In Practice. 07/2013; 1(4):350–353.

Publication Stats

4k Citations
1,369.89 Total Impact Points

Institutions

  • 2013–2014
    • Georgia Regents University
      • Department of Pediatrics
      Augusta, Georgia, United States
  • 1986–2014
    • Henry Ford Hospital
      • Department of Internal Medicine
      Detroit, Michigan, United States
  • 1999–2013
    • Georgia Health Sciences University
      • Department of Pediatrics
      Augusta, Georgia, United States
  • 2012
    • Children's Hospital of Michigan
      Detroit, Michigan, United States
  • 1991–2011
    • Henry Ford Health System
      • • Department of Internal Medicine
      • • Department of Pediatrics
      • • Division of Allergy and Immunology
      Detroit, Michigan, United States
  • 2009
    • University of Illinois at Chicago
      • Division of Epidemiology and Biostatistics
      Chicago, IL, United States
  • 2003–2008
    • Medical College of Georgia
      Атина, Georgia, United States
  • 1997–2008
    • Wayne State University
      • Department of Internal Medicine
      Detroit, MI, United States
  • 2006
    • Baylor College of Medicine
      Houston, Texas, United States
  • 2004
    • Harvard Medical School
      Boston, Massachusetts, United States
  • 2002
    • Johns Hopkins University
      • Department of Medicine
      Baltimore, MD, United States
  • 1990
    • Harper University Hospital
      Detroit, Michigan, United States