Current Indoor Allergen Levels of Fungi and Cats, But Not House Dust Mites, Influence Allergy and Asthma in Adults with High Dust Mite Exposure (original) (raw)
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Exposure to house dust mite allergens and the clinical activity of asthma
Journal of Allergy and Clinical Immunology, 1996
Background: House dust mite allergens play an important role in inducing IgE-mediated sensitization and the development of bronchial hyperresponsiveness (BHR) and asthma. This study investigated the relationship between mite allergen exposure and the clinical activity and severity of asthma. Methods: Nonsmoking adult patients with asthma (n = 53) were randomly recruited from the asthma registry of two large family practitioner surgeries. Each participant underwent skin testing with common inhalant allergens, a methacholine bronchoprovocation test, and pulmonary function testing on up to 3 separate occasions over a 4-week period. BHR was expressed both as PDeo and dose-response ratio (DRR), and the patients with PD2o of less than 12.25/xmol methacholine were classified as methacholine reactors. Patients were also asked to record peak expiratory flow rate (PEFR) values at 2-hour intervals during waking hours for 1 month. Daily PEFR variability was calculated as amplitude percent mean. Dust samples were collected by vacuuming bedding, bedroom carpets and mattresses. In addition, in the homes of 32 subjects with positive skin test responses to mites, airborne samples were taken overnight for 8 hours with a personal sampler attached to each subject's pillow. Der p 1 and Der p 2 levels were determined by a two-site monoclonal antibody-based ELISA. Results: No difference in mite allergen exposure was found between subjects who were sensitive to mites and those who were not. However, mite-sensitive methacholine reactors were exposed to significantly higher concentrations of Der p 1 in beds than mite-sensitive methacholine nonreactors (13.2/xg/gm and 1.45/xg/gm, respectively," p < 0.02). Der p 1 and Der p 2 were undetectable in 30 of 32 airborne samples. In mite-sensitive patients both Der p 1 and Der p 2 in beds significantly correlated with BHR (PDeo: r = -0.49, DRR, r = 0.49; PD2o: r = -0.46, DRR: r = 0.43) and amplitudepercent mean PEFR (r = 0.38, r = 0.41)for Derp 1 and Derp 2, respectively. There was a significant negative correlation between exposure to Der p I and percent predicted FEV 1 (r = -0.43). The correlation between Der p 2 and percent predicted FEV z just failed to reach a significant level but showed a clear trend (r = -0.35, p = 0.068). Conclusions: Clinical activity and severity of asthma (measured by the level of BHR, PEFR variability, and percent predicted FEV1) in mite-sensitive patients is related to exposure to mite allergens in the dust reservoir, with levels in bed being an important indicator that correlated with disease activity. (J Allergy Clin Immunol 1996;98:64-72.) Evidence strongly suggests that the prevalence and severity of asthma is increasing, especially in children, in spite of the availability of effective treatment. 1 House dust mite allergens are a major cause of asthma worldwide, and 45% to 85% of patients with asthma in the United Kingdom show skin test reactivity to mites, as compared with 5% to 30% in the general population. 2 The importance of early exposure to mite allergen in primary sensitization has been suggested by recent studies. Household exposure to levels of Der p 1 greater than 2 Ixg/gm of dust J ALLERGY CLIN IMMUNOL Custovic et al. 65 VOLUME 98, NUMBER 1 Abbreviations used BHR: Bronchial hyperresponsiveness CL: Confidence limits DRR: Dose-response ratio GM: Geometric mean PEFR: Peak expiratory flow rate
Changes in indoor allergen and fungal levels predict changes in asthma activity among young adults
Clinical <html_ent glyph="@amp;" ascii="&"/> Experimental Allergy, 2005
Background Exposures to allergens are thought to be important risk factors for asthma. We conducted a longitudinal study of indoor allergen and fungal levels in Melbourne homes between 1996 and 1998 to examine the effect of changes in allergen exposure upon asthma and associated outcomes. Methods Participants were visited at home in 1996 (n 5 485) and 1998 (n 5 360), when dust and air samples were collected from their bedrooms and assayed for Der p 1, Fel d 1, ergosterol and fungal propagules. Subjects then attended the lung function laboratory to complete a questionnaire, spirometry, methacholine challenge and skin prick testing. The associations between the change in allergen levels and change in clinical outcomes were examined using multiple logistic and linear regression. Results Participants whose Cladosporium fungal exposure doubled had 52% greater odds of having had an attack of asthma in the last 12 months. A doubling of fungal exposure was also associated with 53% greater odds of developing atopy. A doubling of Fel d 1 floor levels was associated with 73% increased odds of doctor-diagnosed asthma. A doubling of Der p 1 levels in bed dust was associated with a 64% greater odds of persistent bronchial hyper-reactivity. Conclusions These findings provide evidence that changes in indoor levels of fungi and house dust mites can affect the risk of development and persistence of asthma and atopy in adults. Further studies are required to establish any benefit of sustained reductions in indoor allergen exposures, and to determine whether these effects are truly 'allergic' or because of immune stimulation in the airway through other less specific mechanisms.
Allergenic materials in the house dust of allergy clinic patients
Annals of Allergy, Asthma & Immunology, 2001
Introduction: Environmental agents including animal, fungal, tree, and weed antigens are known to cause allergic rhinitis and asthma. The following study was performed to measure the antigen concentration of several of these in house dust of children seen in an allergy clinic. Comparisons are made between household allergen levels of children seen for asthma and children seen for other reasons. Methods: Dust samples were solicited from patients in a pediatric allergy specialty clinic and other individuals associated with the clinic. Persons submitting dust were asked to complete a questionnaire describing their house. Samples were extracted, centrifuged, and filtered for sterility. Samples were stored in 50% glycerol at Ϫ20°C. Specific antigens for Alternaria, Cladosporium, Aspergillus, Candida, Dermatophagoides farinae, cat, dog, oak, fescue, ragweed, plantain, and cockroach were measured using inhibition assays developed with whole antigen extract. Allergens Der p1, Der f 1, Alt a 1, and Alt a 70 kD were measured using double monoclonal antibody assays. Results: Significant concentrations of whole antigen from cat, dog, oak, Alternaria, and Cladosporium were detected. Between 0.1 and 18 g of Der f1 and Der p1 per gram of dust were also measured. Alt a 1 and Alt a 70 kD levels varied between 3.0 and 1000 U/g of dust. Significant positive correlations were observed in levels of dust mite and Alternaria allergen for patients with an evaluation of asthma. Conclusions: We found measurable levels of fungal antigens (Alternaria, Cladosporium), mite antigens, and animal antigens (dog and cat) in the majority of dust samples in this self-selected set of allergy clinic patients. Specific allergens Alt a 1, Alt a 70kD, and Der p 1 were significantly higher in the homes of asthmatic patients when compared with patients seen for reasons other than asthma. These studies support the hypothesis that fungal allergen exposure is an important component in the pathogenesis of the clinical condition known as asthma.
Allergic Rhinitis and Asthma in Association with Fungal Pollution of Indoor Environments
Journal of Pediatric and Child Care, 2023
Allergy or asthma is triggered by inhaling allergens such as dust, mites, pet dander, pollens, and fungal molds. Samples were collected from various indoor environments including air conditioner filters, carpets, indoor plant soil, living room air, and pillow covers of fifty residents living in air-conditioned flats for screening the fungal pollution of indoor environments and their role in allergies and asthma. This study included 30 residents with school children suffering from allergies or asthma and a healthy control group of another 20 residential indoor environments. The fungi isolated from indoor environments include Aspergillus niger, A. nidulans, A. flavus, A. fumigatus, Alternaria sp., Paeciliomyces sp, Bipolaris sp, Trichophyton verrucosum, and T. rubrum. Aspergillus species were isolated from all environments while Trichophyton species were isolated from indoor plant soil only. The fungal presence was higher in the indoor environments of group 1 with allergic rhinitis and asthma with a significant p-value <0.00001 showing its role in allergic rhinitis when compared the group 2 without allergy or asthma. The children suffering from allergies and asthma were further grouped into intermittent (70%), persistent (13%), and asthma or allergic asthma (17%) cases based on symptoms and duration. The treatment received with intermittent allergic rhinitis includes a combination of oral antihistamines, and nasal decongestants, while persistent allergy symptoms were treated with corticosteroids (oral/intranasal), oral antihistamines, and oral leukotriene receptor antagonists. Asthma cases were treated with salbutamol sulfate, a bronchodilator, and oral leukotriene receptor antagonists with a combination of antiallergic treatments. A combination of treatments with improved indoor hygiene showed better relief to allergic rhinitis and asthma and was significantly reduced from persistent to intermittent or recovered from allergic symptoms.
Household mold and dust allergens: Exposure, sensitization and childhood asthma morbidity
Environmental Research, 2012
Background: Few studies address concurrent exposures to common household allergens, specific allergen sensitization and childhood asthma morbidity. Objective: To identify levels of allergen exposures that trigger asthma exacerbations in sensitized individuals. Methods: We sampled homes for common indoor allergens (fungi, dust mites (Der p 1, Der f 1), cat (Fel d 1), dog (Can f 1) and cockroach (Bla g 1)) for levels associated with respiratory responses among schoolaged children with asthma (N ¼ 1233) in a month-long study. Blood samples for allergy testing and samples of airborne fungi and settled dust were collected at enrollment. Symptoms and medication use were recorded on calendars. Combined effects of specific allergen sensitization and level of exposure on wheeze, persistent cough, rescue medication use and a 5-level asthma severity score were examined using ordered logistic regression. Results: Children sensitized and exposed to any Penicillium experienced increased risk of wheeze (odds ratio [OR] 2.12 95% confidence interval [CI] 1.12, 4.04), persistent cough (OR 2.01 95% CI 1.05, 3.85) and higher asthma severity score (OR 1.99 95% CI 1.06, 3.72) compared to those not sensitized or sensitized but unexposed. Children sensitized and exposed to pet allergen were at significantly increased risk of wheeze (by 39% and 53% for Fel d 1 40.12 mg/g and Can f 1 41.2 mg/g, respectively). Increased rescue medication use was significantly associated with sensitization and exposure to Der p 1 40.10 mg/g (by 47%) and Fel d 14 0.12 mg/g (by 32%). Conclusion: Asthmatic children sensitized and exposed to low levels of common household allergens Penicillium, Der p 1, Fel d 1 and Can f 1 are at significant risk for increased morbidity.
Mouldy houses influence symptoms of asthma among atopic individuals
Clinical <html_ent glyph="@amp;" ascii="&"/> Experimental Allergy, 2002
Background The in¯uence of current levels of indoor fungi on asthma is a controversial issue that needs to be resolved in order to advise patients appropriately. Objective To assess the seasonal variation in indoor fungal levels and the impact of these levels on asthma among mould-sensitized individuals. Methods Thirty-®ve young adults with current asthma and sensitization to fungi were visited four times over 1 year. At each home visit a questionnaire was administered and samples of dust and air were collected. Participants also recorded information on symptoms, peak expiratory¯ows (PEF) and medication use. Dust samples were analysed for house dust mite allergen (Der p 1) and total fungal biomass (ergosterol). Total and genus-speci®c fungal propagules were identi®ed in air samples. Seasonal variation in allergen levels and signi®cant independent effects of fungal levels on peak¯ow variability (PFV) were identi®ed by repeated measures analysis of variance. Results Signi®cant seasonal variations were observed in viable airborne fungi, ergosterol levels in the¯oor dust and PFV. PFV correlated signi®cantly with symptom scores and the dose of reliever medication. PFV was also signi®cantly associated with smoking and visible mould. The association between visible mould and PFV was independent of season, smoking and the dose of reliever medication. However, there was no association between total fungi, speci®c fungi or ergosterol and PFV. Der p 1 levels had no signi®cant in¯uence on asthma, even in HDM-sensitized individuals. Conclusions Mouldy homes adversely in¯uence asthma in asthmatics sensitized to fungi.
Indoor Air, 2003
Normally a single site from the floor is sampled for assessment of house dust-mite and cat allergen exposure. This study has shown a large variation of these allergens within living rooms and thus allergen assessment from a single site may not be representative of an individual's exposure risk. However, for large-scale epidemiological studies, a single site from the center of the room, in front of a couch or chair, or from a corner of the room is representative of the whole living room floor.
Is the risk of allergic hypersensitivity to fungi increased by indoor exposure to moulds?
International Journal of Occupational Medicine and Environmental Health, 2009
Objectives: Moulds are frequently found in the indoor environment of residential houses. An association between domestic mould contamination and respiratory symptoms has been reported, but mould exposure as a risk factor for allergy to moulds is not well documented. The aim of the study was to evaluate the prevalence and associated factors of allergic hypersensitivity to moulds. Materials and Methods: A group of 243 participants was examined. Of these 118 lived in dwellings with evident signs of fungal contamination (study group) and 125 in non-contaminated sites (controls). An interview, skin prick tests to common and fungal allergens, evaluation of total serum IgE and specific IgE to moulds, resting spirometry as well as mycological analysis in building were performed for each participant. Results: 19.8% subjects were sensitized to at least one mould allergen. Logistic regression analysis revealed that the history of respiratory and skin symptoms, smoking cigarettes in the past and positive skin prick tests (SPT) to common allergens (dust mite and grass pollens) or the presence of a cat as a pet animal were the significant associated factors of hypersensitivity to moulds. Conclusions: The association between indoor fungal exposure and the development of fungal allergy was not confirmed in our study.
Variable risk of atopic disease due to indoor fungal exposure in NHANES 2005-2006
Clinical and experimental allergy : journal of the British Society for Allergy and Clinical Immunology, 2015
Exposure to damp indoor environments is associated with increased risk of eczema, allergy and asthma. The role of dampness-related exposures and risk of allergic diseases are yet to be fully explored in a US population. We assess whether exposure to fungi, house dust mites and endotoxin increase the risk of eczema, allergy and asthma in children and adults participating in NHANES 2005-2006. A total of 8,412 participants (2,849 were children aged between 6 and 17 years) were recruited in the 2005-2006 survey. We used multiple logistic regression to investigate whether mildew/musty odour, and increased concentrations of Alternaria alternata allergen, Aspergillus fumigatus antigens, house dust mite and endotoxin antigens increase risk of eczema, allergy and asthma. We stratified models by total IgE <170 and ≥170 KU/L to assess allergic and non-allergic asthma outcomes. Exposure to multiple biological agents and risk of reporting eczema, allergy and asthma was also investigated. Repo...