Study of Cat Allergy Using Controlled Methodology—A Review of the Literature and a Call to Action (original) (raw)
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Journal of Allergy and Clinical Immunology, 2020
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Is There a Threshold Concentration of Cat Allergen Exposure on Respiratory Symptoms in Adults?
PloS one, 2015
Cat allergen concentrations higher than 8 μg/g in settled house dust, have been suggested to provoke exacerbation of allergic respiratory symptoms. However, whether the 8μg/g of indoor cat allergen concentration is indeed the minimal exposure required for triggering the asthma related respiratory symptoms or the development of sensitization has not yet been confirmed. We studied the associations between domestic cat allergen concentrations and allergic symptoms in the European Community Respiratory Health Survey II, with the aim of confirming this suggested threshold. Cat allergen concentrations were measured in the mattress dust of 3003 participants from 22 study centres. Levels of specific immunoglobulin E to cat allergens were measured in serum samples using an immunoassay. Information on allergic symptoms, medication use, home environment and smoking was obtained from a face-to-face interview. Domestic cat allergen concentrations were not associated with allergic/ asthmatic symp...
Cat allergen level: Its determinants and relationship to specific IgE to cat across European centers
Journal of Allergy and Clinical Immunology, 2006
Background: Cat allergen level in settled house dust and its determinants in Europe are unknown. Objective: The aim of this study is to quantify the level of cat allergens in mattress dust, to study its determinants, and to analyze the relationship with cat specific IgE on community level across European centers. Methods: Trained field workers collected dust from approximately 3000 mattresses during home visits in 22 European Community Respiratory Health Survey II centers. Sieved dust extracts were assayed for cat allergen using a mAb ELISA assay. Results: The overall geometric mean cat allergen was 0.94 mg/g, ranging from 0.12 mg/g in Huelva, Spain, to 3.76 mg/g in Antwerp, Belgium. Current cat owners' homes showed substantially higher levels than past cat owners' and never cat owners' homes (geometric mean and 95% CI, 61.4 mg/g [48.4-77.9] vs 1.37 mg/g [0.97-1.9] vs 0.29 mg/g [0.27-0.31]). Community prevalence of cat ownership was moderately correlated with cat allergen levels in noncat owners (r s 5 0.50), but not for past or current cat owners. The multilevel model identified community prevalence of cat keeping as the only statistically significant determinant of mattress cat allergen levels for noncat owners. However, averaged cat allergen levels per center were not related to community prevalence of detectable specific IgE to cat. Conclusion: Not having a cat in the home is associated with substantially lower Fel d 1 concentration, but does not protect against high Fel d 1 exposure in communities where cat ownership is common. Clinical implications: People (including patients with cat allergy) who do not own cats may be exposed to high levels of cat allergen in their home, particularly if they live in communities with high levels of cat ownership. (J Allergy Clin Immunol 2006;118:674-81.)
Sensitization to cat allergen and its association with respiratory allergies: cross-sectional study
Sao Paulo medical journal = Revista paulista de medicina, 2017
Cats are a significant source of allergens that contribute towards worsening of allergic diseases. The aim of this study was to investigate the association between sensitization to cat allergens and allergic respiratory diseases.This was an observational retrospective study based on the skin pricktests results of patients at a tertiary-level hospital in São Paulo. A total of 1,985 test results were assessed. The prevalence of sensitization to cat allergen was 20% (399 patients). Our data indicated that in this population of atopic patients, a positive skin prick test result for cat allergen was not associated significantly with a diagnosis of respiratory allergy.
Journal of Allergy and Clinical Immunology, 1997
Background: Why allergic subjects may have asthma or rhinitis on allergen exposure remains unclear. Objective: This study was carried out to compare airway responses during environmental allergen challenge (EAC) with quantitative allerge n provocation challenges of the upper and lower airways. Methods: Thirteen subjects with allergy to cats underwent EAC to cats. Lower airway responses during EAC were compared with bronchoprovocation with allergen. Nasal mucosal challenge with allergen-soaked disks were compared with EAC nasal responses. Nonspecific bronchial reactivity was assessed with methacholine: allergen sensitivity was assessed by skin prick tests. RAST. and end-point skin titration. Results: During EAC, the maximal fall in FEV 1 ranged from 6% to 57% (median, 18%) and correlated closely with allergen bronchoprovocation PD2o (Spearman's correlation coefficient [Rs] =-0.85, p < 0.0002). EAC asthmatic responses and allergen bronchoprovocation correlated with methacholine PD2o (R s =-0.85, p = 0.0002 and Rs = 0.83, p = 0.0004, respectively). Nasal provocation and EAC nasal responses correlated with each other but not with lower airway responses. On the basis of EAC and allergen bronchoprovocation responses, seven participants with asthma were identified. This group was significantly more sensitive to inhaled methacholine but was similar to the nonasthmatic group in IgE-mediated sensitivity and nasal responses. Conclusions: The lower respiratory tract is less responsive to allergic and nonallergic stimuli in persons with allergic rhinitis. In persons with asthma during EAC, the response to nebulized cat allergen is also abnormal and correlates closely with their abnormal responsiveness to nonimmunologic stimuli. (
Decreased prevalence of sensitization to cats with high exposure to cat allergen
Journal of Allergy and Clinical Immunology, 2001
We investigated the relationship between current exposure to cat allergen and sensitization to cats. A questionnaire was administered and skin prick testing and home visits for collection of dust samples (Fel d 1; ELISA) were performed in 2502 adults (mean age, 31.8 years; age range, 18-58 years; 1251 women). The results for Fel d 1 in relation to sensitization to cats were analyzed for 10 deciles of cat allergen exposure (cut points [µg/g]: 0.05, 0.34, 0.48, 0.72, 1.13, 1.92, 7.2, 44, 151). The prevalence of sensitization to cat was significantly decreased in the lowest and the highest exposure groups. In the multivariate regression analysis (age, sex, socioeconomic status, and current smoking being adjusted for), the risk of sensitization to cats was significantly increased with medium exposure to Fel d 1 (3rd centile, OR 2.3, 95% CI 1.2-4.4, P = .01; 4th centile, OR 2.1, 95% CI 1.1-4.0, P = .03; 5th centile, OR 2.2, 95% CI 1.2-4.3, P = .04, 6th centile, OR 2.5, 95% CI 1.3-4.9, P = .005). These results indicate that the prevalence of sensitization to cat is decreased in the lowest and highest cat allergen exposure groups.(J Allergy Clin Immunol 2001;108:537-9.)
Cat antigen in homes with and without cats may induce allergic symptoms†
Journal of Allergy and Clinical Immunology, 1996
Although Fel d 1, the major cat allergen, has been found in settled dust samples from homes both with and without cats, the clinical relevance of this allergen has never been studied. In this study we measured airborne concentrations of Fel d 1 in homes both with and without cats and then attempted to relate these levels to those obtained in our experimental cat challenge model to assess their clinical significance. In baseline samples we found measurable levels of airborne Fel d 1 in all 37 homes with cats (range, 1.8 to 578 ng/m3; median, 45.9 ng/m3) and in 10 of the 40 homes without cats (for detectable samples: range, 2.8 to 88.5 ng/m3; median, 17 ng/m3). Fel d 1 was present in the settled dust of 38 of 40 homes without cats (range, 39 to 3750 ng/gm; median, 258 ng/gm), although these levels were only weakly predictive of airborne levels. Repeat samples obtained weekly from 12 homes without cats yielded measurable airborne levels. Fel d 1 in at least one of the four samples from all homes. When compared with challenges performed in our cat room facility at low levels of airborne Fel d 1 (&amp;lt;500 ng/m3), these home levels are within the range capable of causing upper and lower respiratory symptoms in subjects allergic to cats. We therefore conclude that the low level cat exposure that occurs in many homes without cats is capable of inducing symptoms in some patients who are sensitive to cats. The assessment of cat exposure should not be based solely on the presence or absence of a cat in the home.
Annals of Allergy, Asthma & Immunology, 2003
Background: Treatment of cat allergy normally entails removal of the cat from the household, but cat owners are often unwilling to part with their pets, despite clinically relevant allergies. Objective: To determine whether levels of Fel d 1 can be reduced without removal of the cat and whether this will affect symptoms of cat allergy. Methods: Cat-allergic patients underwent randomization to either a group instructed in environmental control (EC) and a group with unchanged environment (UE). Dust samples were obtained and settled Fel d 1 measured by enzyme-linked immunosorbent assay. Patients recorded daily nasal inspiratory flow rates. At baseline, 3 months, and 8 months, patients underwent symptom evaluation. Results: Eighteen patients were randomized to the EC group and 22 to the UE group; the final number completing the study was 31, 15 in the EC group, and 16 in the UE group. At 8 months, home Fel d 1 levels had diminished to 6.8% of baseline levels in the EC group, whereas no reduction in levels was noted in the UE group. In the EC group, significant improvements were found in nasal inspiratory flow rate and symptoms compared with the UE group. Patients did not have difficulties adhering to EC measures. Conclusion: A decrease in the allergen load was found in the EC group, which had a significant effect on symptoms of nasal allergy.
Role of current and childhood exposure to cat and atopic sensitization☆☆☆★
Journal of Allergy and Clinical Immunology, 1999
Background: Clinical and population studies have shown that exposure and sensitization to allergens derived from furred pets, particularly cats, represent an important risk factor of allergic respiratory disease and also a significant risk factor for asthma. Objective: In the framework of the multicenter European Community Respiratory Health Survey an analysis of the association of current and childhood exposure to cat with atopic sensitization to cat was conducted. Methods: This study included cross-sectional data from 35 centers representing 16 countries. Altogether, 18,097 subjects were included, of whom 13,509 (75%) provided a blood sample for the measurement of specific IgE. Exposure data and data for potential confounders were extracted from an interviewerled questionnaire. Results: The prevalence of sensitization to cat (serum specific IgE >0.35 kU/L) was 9%. Among those who did not report allergic symptoms in the presence of pets or house dust, those who owned cats were significantly more likely to be sensitized to cats than were those who did not (odds ratio [95% confidence interval] 1.57 [1.20-2.06]. Childhood exposure to pets including cats was associated with lower sensitization to cats in adulthood, particularly among those with a positive family history of atopy (odds ratio [95% confidence interval] 0.68 [0.51-0.93]. Positive correlations were found between the community prevalence of cat and the prevalences of sensitization to cat, respiratory symptoms, physician-diagnosed asthma, and current asthma medication. Conclusions: Current cat ownership represents a significant risk for sensitization to cat if cats are allowed indoors. Our results support the hypothesis that childhood exposure to pets, including cats, might modulate immunologic mechanisms and reduce sensitization to cat in adulthood. The significant corre-lation found between the community prevalence of cat ownership and community prevalence of specific sensitization to cat represents the first documentation of such a relationship. (J Allergy Clin Immunol 1999;104:941-7.) 942 Roost et al J ALLERGY CLIN IM M UNOL NOVEM BER 1999
Allergen avoidance does not alter airborne cat allergen levels in classrooms
Allergy, 2004
Background: Some schools in Sweden offer allergen avoidance classrooms for allergic children with severe asthma. However, the measures commonly used to achieve a reduction in allergen levels have not been properly evaluated. The aim of the present prospective study was to study whether the levels of airborne cat allergen are altered after introducing feasible intervention measures in classrooms, without interfering with peoples’ freedom of choice regarding pet ownership.Methods: Twenty‐five classes, including five established allergy prevention classrooms participated in the study during a school year. After one term, six classes underwent a number of intervention measures recommended by the Swedish National Institute of Public Health. Curtains, upholstery and plants were removed, bookshelves were replaced with cupboards and regular cleaning was increased. Airborne dust was collected weekly (32 weeks) using duplicate Petri dishes (n = 1574) and on six occasions using two personal ...