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Wypych-Ślusarska A, Krupa-Kotara K, Oleksiuk K, Głogowska-Ligus J, Słowiński J. Respiratory Status in Children and Exposure to Animal Allergens-The Problem of Reverse Causality in Cross-Sectional Studies. CHILDREN (BASEL, SWITZERLAND) 2024; 11:941. [PMID: 39201876 PMCID: PMC11353102 DOI: 10.3390/children11080941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 07/26/2024] [Accepted: 07/31/2024] [Indexed: 09/03/2024]
Abstract
BACKGROUND Some epidemiological studies suggest that early exposure to animal allergens during infancy reduces the risk of bronchial asthma in school-age children. However, the observed associations in some cases may be an effect of the study used (epidemiological observational studies, especially a cross-sectional study) and indicate reverse causality. AIM This study aimed to determine the association between exposure to animal allergens and the prevalence of respiratory diseases, including bronchial asthma, considering the potential impact of reverse causality on the observed relationships. MATERIAL AND METHODS An analysis of data from a cross-sectional epidemiological study conducted in 2020 involving 3237 primary school students aged 7-15 years in the Silesian Province (Southern Poland) was carried out. The parents of students completed a questionnaire based on The International Study on Asthma and Allergies in Childhood (ISAAC). The relationship between the occurrence of chronic cough, wheezing, and dyspnea in the last 12 months, night waking due to dyspnea, and asthma in the presence of pets was assessed. Exposure to animal allergens was determined by answering the question, "Are there any furry or feathered animals in the home?" with three response options: "yes; they have been in the past; no" (Scenario 1). For the analyses and to reveal a potential reverse causality effect, the last two response categories regarding pet ownership were combined to form a "no" category in Scenario 2, and the first two answers were combined into a "yes" category in Scenario 3. A chi-square test was used to assess the relationship between variables, and a statistical significance level of p < 0.05 was adopted. RESULTS Chronic cough affected 9.5% of children, wheezing in the last 12 months-9.2%, night waking due to dyspnea-5.8%, dyspnea in the last 12 months-4.8%, bronchial asthma-9.2%. Analysis considering the category of having or not having pets (yes vs. no) showed that bronchial asthma was statistically significantly more common in children who did not have pets at home (10.9% vs. 7.9%, p = 0.002). A similar situation was observed for wheezing in the past 12 months (10.7% vs. 8.1%; p = 0.01) and nocturnal awakening due to dyspnea (6.8% vs. 5.1%, p = 0.03). No statistically significant differences were observed for the other symptoms. Analysis by time of pet ownership (a. present; b. present but in the past; c. not present) highlighted similar relationships. Asthma (a. 7.7% vs. b. 13.4% vs. c. 7.7%; p = 0.004), wheezing in the past 12 months (a. 8.1% vs. b. 8.9% vs. c. 10.9%, p = 0.03) and night waking (a. 5.0% vs. b. 4.5% vs. c. 7.1%; p = 0.04) were more common in children without pets and those who had owned pets in the past. The highest proportion of children with asthma was in homes where pets were present in the past. CONCLUSIONS Analyses indicating a relationship between a higher prevalence of asthma and some respiratory symptoms, and the absence of pets cannot be considered as a casual association. The analysis conducted did not reveal a reverse causality effect. The results of observational epidemiological studies, especially a cross-sectional study, should always be interpreted with caution, considering possible distortions and conclusions drawn.
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Affiliation(s)
| | - Karolina Krupa-Kotara
- Department of Epidemiology, Faculty of Public Health in Bytom, Medical University of Silesia, 40-055 Katowice, Poland; (A.W.-Ś.); (K.O.); (J.G.-L.); (J.S.)
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Associations of early-life pet ownership with asthma and allergic sensitization: a meta-analysis of >77,000 children from the EU Child Cohort Network. J Allergy Clin Immunol 2022; 150:82-92. [PMID: 35150722 DOI: 10.1016/j.jaci.2022.01.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 01/18/2022] [Accepted: 01/21/2022] [Indexed: 11/22/2022]
Abstract
BACKGROUND Studies examining associations of early-life cat and dog ownership with childhood asthma have reported inconsistent results. Several factors could explain these inconsistencies, including type of pet, timing and degree of exposure. OBJECTIVE To study associations of early-life cat and dog ownership with school-age asthma, including the role of type (cat versus dog), timing (never, prenatal or early childhood) and degree (number) of ownership, and the role of allergic sensitisation. METHODS We used harmonised data from 77,434 mother-child dyads aged 5-11 years from nine birth cohorts in the EU Child Cohort Network. Associations were examined through the DataSHIELD platform using adjusted logistic regression models, fitted separately for each cohort and combined using random-effects meta-analysis. RESULTS Early-life cat and dog ownership ranged between 12-45% and 7-47% respectively, and prevalence of asthma between 2-20%. There was no overall association between either cat or dog ownership and asthma (OR: 0.97 (95% CI: 0.87-1.09) and 0.92 (0.85-1.01), respectively). Timing and degree of ownership did not strongly influence associations. Cat and dog ownership were also not associated with cat- and dog-specific allergic sensitisation (OR: 0.92 (0.75-1.13) and 0.93 (0.57-1.54), respectively). However, cat- and dog-specific allergic sensitisation were strongly associated with school-age asthma (OR: 6.69 (4.91-9.10) and 5.98 (3.14-11.36), respectively). There was also some indication of an interaction between ownership and sensitisation, suggesting that ownership may exacerbate the risks associated with pet-specific sensitisation, but offer some protection against asthma in the absence of sensitisation. CONCLUSION Our findings do not support early-life cat and dog ownership in themselves increasing the risk of school-age asthma, but suggest that ownership may potentially exacerbate the risks associated with cat- and dog-specific allergic sensitisation.
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Yang MS, Lee SP, Kwon YJ, Lee SM. Dog and Cat Allergies and Allergen Avoidance Measures in Korean Adult Pet Owners Who Participated in a Pet Exhibition. ALLERGY, ASTHMA & IMMUNOLOGY RESEARCH 2018; 10:155-164. [PMID: 29411556 PMCID: PMC5809764 DOI: 10.4168/aair.2018.10.2.155] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 12/02/2017] [Accepted: 12/06/2017] [Indexed: 01/12/2023]
Abstract
Purpose This study evaluated dog and cat allergies and their association with allergen avoidance measures in Korean adults. Methods The study population consisted of 537 adults who currently kept dogs or cats and participated in a pet exhibition in Korea. The subjects were asked to complete questionnaires regarding pet ownership, allergen avoidance, and allergy symptoms, and underwent skin prick tests. They were considered to have a dog or cat allergy if they suffered from one or more of allergy symptoms during contact with their pets. Results In total, 103 of 407 dog owners (25.3%) and 45 of 130 cat owners (34.6%) had a dog or cat allergy, respectively. Dog owners kept 1.3±1.5 dogs; this number did not differ according to the presence of dog allergy. Dog owners with a dog allergy had owned their dogs longer than those without (88.0±72.0 vs 67.5±72.7 months, P<0.05). Cat owners kept 2.1±3.6 cats; this number did not differ according to the presence of cat allergy, nor did the duration of cat ownership. Cat owners with a cat allergy had facial contact and slept with their cats less frequently (8.6±11.9 vs 18.3±27.0 times/day, P<0.01; 71.1% vs 81.2%, P<0.05); however, they had their cats shaved and beds cleaned less frequently than those without (1.8±3.3 vs 3.2±4.4 times/year, P<0.05; 1.5±1.5 vs 3.9±6.0 times/month, P<0.01). Conclusions Cat owners with a cat allergy tried to minimize contact with their cats, but efforts to avoid indoor cat allergens were lower than those without. In comparison, dog owners with a dog allergy had kept their dogs for longer time than those without; however, current contact with their dogs and allergen avoidance measures did not differ between the 2 groups.
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Affiliation(s)
- Min Suk Yang
- Department of Internal Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea
| | - Sang Pyo Lee
- Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea
| | - Young Jae Kwon
- Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea
| | - Sang Min Lee
- Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, Korea.
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Tun HM, Konya T, Takaro TK, Brook JR, Chari R, Field CJ, Guttman DS, Becker AB, Mandhane PJ, Turvey SE, Subbarao P, Sears MR, Scott JA, Kozyrskyj AL. Exposure to household furry pets influences the gut microbiota of infant at 3-4 months following various birth scenarios. MICROBIOME 2017; 5:40. [PMID: 28381231 PMCID: PMC5382463 DOI: 10.1186/s40168-017-0254-x] [Citation(s) in RCA: 171] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 03/14/2017] [Indexed: 05/25/2023]
Abstract
BACKGROUND Early-life exposure to household pets has the capacity to reduce risk for overweight and allergic disease, especially following caesarean delivery. Since there is some evidence that pets also alter the gut microbial composition of infants, changes to the gut microbiome are putative pathways by which pet exposure can reduce these risks to health. To investigate the impact of pre- and postnatal pet exposure on infant gut microbiota following various birth scenarios, this study employed a large subsample of 746 infants from the Canadian Healthy Infant Longitudinal Development Study (CHILD) cohort, whose mothers were enrolled during pregnancy between 2009 and 2012. Participating mothers were asked to report on household pet ownership at recruitment during the second or third trimester and 3 months postpartum. Infant gut microbiota were profiled with 16S rRNA sequencing from faecal samples collected at the mean age of 3.3 months. Two categories of pet exposure (i) only during pregnancy and (ii) pre- and postnatally were compared to no pet exposure under different birth scenarios. RESULTS Over half of studied infants were exposed to at least one furry pet in the prenatal and/or postnatal periods, of which 8% were exposed in pregnancy alone and 46.8% had exposure during both time periods. As a common effect in all birth scenarios, pre- and postnatal pet exposure enriched the abundance of Oscillospira and/or Ruminococcus (P < 0.05) with more than a twofold greater likelihood of high abundance. Among vaginally born infants with maternal intrapartum antibiotic prophylaxis exposure, Streptococcaceae were substantially and significantly reduced by pet exposure (P < 0.001, FDRp = 0.03), reflecting an 80% decreased likelihood of high abundance (OR 0.20, 95%CI, 0.06-0.70) for pet exposure during pregnancy alone and a 69% reduced likelihood (OR 0.31, 95%CI, 0.16-0.58) for exposure in the pre- and postnatal time periods. All of these associations were independent of maternal asthma/allergy status, siblingship, breastfeeding exclusivity and other home characteristics. CONCLUSIONS The impact of pet ownership varies under different birth scenarios; however, in common, exposure to pets increased the abundance of two bacteria, Ruminococcus and Oscillospira, which have been negatively associated with childhood atopy and obesity.
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Affiliation(s)
- Hein M Tun
- Department of Pediatrics, University of Alberta, 3-527 Edmonton Clinic Health Academy, 11405-87th Avenue, Edmonton, AB, T6G IC9, Canada
| | - Theodore Konya
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Tim K Takaro
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Jeffrey R Brook
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Radha Chari
- Department of Obstetrics and Gynecology, University of Alberta, Edmonton, AB, Canada
| | - Catherine J Field
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - David S Guttman
- Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, ON, Canada
| | - Allan B Becker
- Department of Pediatrics and Child Health, Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, Canada
| | - Piush J Mandhane
- Department of Pediatrics, University of Alberta, 3-527 Edmonton Clinic Health Academy, 11405-87th Avenue, Edmonton, AB, T6G IC9, Canada
| | - Stuart E Turvey
- Department of Pediatrics, Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Padmaja Subbarao
- Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Malcolm R Sears
- Department of Medicine, McMaster University, Hamilton, ON, Canada
| | - James A Scott
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Anita L Kozyrskyj
- Department of Pediatrics, University of Alberta, 3-527 Edmonton Clinic Health Academy, 11405-87th Avenue, Edmonton, AB, T6G IC9, Canada.
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Breitenbuecher C, Belanger JM, Levy K, Mundell P, Fates V, Gershony L, Famula TR, Oberbauer AM. Protein expression and genetic variability of canine Can f 1 in golden and Labrador retriever service dogs. Canine Genet Epidemiol 2016; 3:3. [PMID: 27110374 PMCID: PMC4840867 DOI: 10.1186/s40575-016-0031-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Accepted: 03/03/2016] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Valued for trainability in diverse tasks, dogs are the primary service animal used to assist individuals with disabilities. Despite their utility, many people in need of service dogs are sensitive to the primary dog allergen, Can f 1, encoded by the Lipocalin 1 gene (LCN1). Several organizations specifically breed service dogs to meet special needs and would like to reduce allergenic potential if possible. In this study, we evaluated the expression of Can f 1 protein and the inherent variability of LCN1 in two breeds used extensively as service dogs. Saliva samples from equal numbers of male and female Labrador retrievers (n = 12), golden retrievers (n = 12), and Labrador-golden crosses (n = 12) were collected 1 h after the morning meal. Can f 1 protein concentrations in the saliva were measured by ELISA, and the LCN1 5' and 3' UTRs and exons sequenced. RESULTS There was no sex effect (p > 0.2) nor time-of-day effect; however, Can f 1 protein levels varied by breed with Labrador retrievers being lower than golden retrievers (3.18 ± 0.51 and 5.35 ± 0.52 μg/ml, respectively, p < 0.0075), and the Labrador-golden crosses having intermediate levels (3.77 ± 0.48 μg/ml). Although several novel SNPs were identified in LCN1, there were no significant breed-specific sequence differences in the gene and no association of LCN1 genotypes with Can f 1 expression. CONCLUSIONS As service dogs, Labrador retrievers likely have lower allergenic potential and, though there were no DNA sequence differences identified, classical genetic selection on the estimated breeding values associated with salivary Can f 1 expression may further reduce that potential.
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Affiliation(s)
| | - Janelle M Belanger
- Department of Animal Science, University of California, One Shields Ave, Davis, CA 95616 USA
| | - Kerinne Levy
- Canine Companions for Independence, Santa Rosa, CA USA
| | - Paul Mundell
- Canine Companions for Independence, Santa Rosa, CA USA
| | - Valerie Fates
- Department of Animal Science, University of California, One Shields Ave, Davis, CA 95616 USA
| | - Liza Gershony
- Department of Animal Science, University of California, One Shields Ave, Davis, CA 95616 USA
| | - Thomas R Famula
- Department of Animal Science, University of California, One Shields Ave, Davis, CA 95616 USA
| | - Anita M Oberbauer
- Department of Animal Science, University of California, One Shields Ave, Davis, CA 95616 USA
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Jensen-Jarolim E, Pacios LF, Bianchini R, Hofstetter G, Roth-Walter F. Structural similarities of human and mammalian lipocalins, and their function in innate immunity and allergy. Allergy 2016; 71:286-94. [PMID: 26497994 PMCID: PMC4949658 DOI: 10.1111/all.12797] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2015] [Indexed: 01/08/2023]
Abstract
Owners and their domestic animals via skin shedding and secretions, mutually exchange microbiomes, potential pathogens and innate immune molecules. Among the latter especially lipocalins are multifaceted: they may have an immunomodulatory function and, furthermore, they represent one of the most important animal allergen families. The amino acid identities, as well as their structures by superposition modeling were compared among human lipocalins, hLCN1 and hLCN2, and most important animal lipocalin allergens, such as Can f 1, Can f 2 and Can f 4 from dog, Fel d 4 from cats, Bos d 5 from cow's milk, Equ c 1 from horses, and Mus m 1 from mice, all of them representing major allergens. The β-barrel fold with a central molecular pocket is similar among human and animal lipocalins. Thereby, lipocalins are able to transport a variety of biological ligands in their highly conserved calyx-like cavity, among them siderophores with the strongest known capability to complex iron (Fe(3+) ). Levels of human lipocalins are elevated in nonallergic inflammation and cancer, associated with innate immunoregulatory functions that critically depend on ligand load. Accordingly, deficient loading of lipocalin allergens establishes their capacity to induce Th2 hypersensitivity. Our similarity analysis of human and mammalian lipocalins highlights their function in innate immunity and allergy.
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Affiliation(s)
- E Jensen-Jarolim
- The interuniversity Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University Vienna, University Vienna, Vienna, Austria
- Institute of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology and Immunology, Medical University Vienna, Vienna, Austria
| | - L F Pacios
- Biotechnology Department, Center for Plant Biotechnology and Genomics, ETSI Montes, Technical University of Madrid, Madrid, Spain
- Department of Natural Systems and Resources, ETSI Montes, Technical University of Madrid, Madrid, Spain
| | - R Bianchini
- The interuniversity Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University Vienna, University Vienna, Vienna, Austria
| | - G Hofstetter
- The interuniversity Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University Vienna, University Vienna, Vienna, Austria
| | - F Roth-Walter
- The interuniversity Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University Vienna, University Vienna, Vienna, Austria
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Pyrhönen K, Näyhä S, Läärä E. Dog and cat exposure and respective pet allergy in early childhood. Pediatr Allergy Immunol 2015; 26:247-255. [PMID: 25735463 DOI: 10.1111/pai.12369] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/28/2015] [Indexed: 11/27/2022]
Abstract
BACKGROUND The association of dog and cat exposure in early childhood with the incidence of respective allergies has remained controversial. The aim of the study was to obtain population-based evidence on the association of early exposure to dog or cat, or both, with dog and cat allergies. METHODS The study population was identified from the nationwide population register comprising all children aged 1-4 yr (N = 4779) born between 2001 and 2005 and living in the province of South Karelia, Finland. Cross-sectional questionnaire data on pet exposure in infancy and physician-diagnosed pet allergies were obtained from 3024 participants and merged with longitudinally accumulated data on sIgE and skin prick tests indicating allergic sensitization abstracted from all patient records in the area. RESULTS The adjusted relative incidence of positive test results (with 95% confidence intervals) was 2.69 (1.45-5.02) for dog and 5.03 (2.47-10.2) for cat allergens among children exposed to a respective pet alone compared with children without such exposure. The corresponding adjusted prevalence odds ratios for diagnosed dog and cat allergies were 1.75 (0.77-3.79) and 5.13 (2.30-11.4), respectively. The association between pet exposure and the incidence of positive test results was independent of parents' allergies. CONCLUSIONS Early exposure to dog and cat at home is associated with a higher incidence of respective pet allergy during the first four years of life. Further evidence from population-based studies with longer follow-up is required to justify any recommendation concerning early pet contacts with a view to preventing pet allergies later in life.
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Affiliation(s)
- Kaisa Pyrhönen
- Centre for Lifecourse Epidemiology and Systems Medicine, University of Oulu, Oulu, Finland.,South Karelia District of Social and Health Services, Lappeenranta, Finland
| | - Simo Näyhä
- Center for Environmental and Respiratory Health Research, University of Oulu, Oulu, Finland
| | - Esa Läärä
- Department of Mathematical Sciences, University of Oulu, Oulu, Finland
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