Abstract
The authors investigated the relationship between respiratory symptoms in adults and exposure to mite and cat allergens, the role of endotoxins in house dust, the effects of mixtures of several allergens, and interactions between allergen exposure and allergic sensitization.
Within a nested case-control study, 405 subjects aged 25–50 yrs from two German cities answered a standardized questionnaire. Allergen-specific immunoglobulin-E was measured. Dust samples were taken from the subjects' homes to determine exposure to mite (Dermatophagoides pteronyssinus antigen 1 Der p 1) and (D. farinae antigen 1 Der f 1) and cat (cat antigen d1 Fel d 1) allergen and endotoxin content in settled house dust.
Exposure to Der f 1 and Der p 1 plus Der f 1 >10 µg·g−1 of mattress dust, respectively, increased the risk of wheeze and breathlessness (odds ratios (OR): 4.04, 95% confidence interval (CI): 1.53–10.64, OR: 2.78, 95% CI: 1.06–7.28). Fel d 1 >8 µg·g−1 was positively associated with cough at night (OR: 2.74, 95% CI: 1.22–6.17), noteworthy also in the nonsensitized subjects. Subjects exposed to elevated concentrations of more than one allergen had an up to seven-fold increase in the risk of respiratory symptoms, compared to nonexposed subjects. Sensitized subjects exposed to elevated concentrations of Der f 1 or Fel d 1 were found to have the highest risk of asthma attacks and respiratory symptoms. No statistically significant association was found between exposure to endotoxins and respiratory health.
Indoor exposure to Dermatophagoides farinae antigen 1 and cat antigen d1 is a risk factor for respiratory symptoms in adults, and for cat antigen d 1 even in nonsensitized subjects. The risk is increased if subjects are exposed to a mixture of allergens or if they are sensitized in addition to high exposure.
The prevalence of asthma and immunoglobulin-E (IgE)-mediated atopic diseases increased in many Western countries over recent decades 1. Inhalant allergens play a major role in the pathogenesis of allergic asthma and allergic rhinitis. Indoor allergens from house dust mites, cat dander, cockroaches, and fungi are of particular importance. The house dust mites Dermatophagoides pteronyssinus and D. farinae are the predominant sources of inhalant allergens in most parts of the world 2.
Which individual indoor allergen plays the major role, is a question of area-specific exposure to a single allergen or a mixture of several allergens. As mites cannot survive in very dry climatic conditions, exposure to mites does not play a major role in the development of allergic sensitization in dry climates 3. Cockroaches may be the predominant allergen exposure in USA inner cities 4, 5, but not in Germany 6.
There is increasing evidence for the impact of allergen exposure early in life on the development of allergic sensitization 7–9, but exposure to allergens later in life might be, at least in sensitized subjects, associated with the development of persistent inflammation in the airway wall, and consequently, with respiratory symptoms.
The aim of this paper was to study the relationship between asthma attacks and respiratory symptoms in adults and exposure to mite and cat allergen content in settled house dust. As allergen exposure constitutes only one element of the indoor environment, and differences in allergen levels could reflect overall differences in the indoor environment, the role of endotoxins was also studied. Furthermore, the effect of mixtures of several indoor allergens and interactions between indoor allergen exposure and allergic sensitization was analysed.
Within a nested case-control study, 405 subjects aged 25–50 yrs from two German cities answered a standardized questionnaire. Allergen-specific immunoglobulin-E was measured. Dust samples were taken from the subjects' homes to determine exposure to mite (Dermatophagoides pteronyssinus antigen 1 Der p 1) and (D. farinae antigen 1 Der f 1) and cat (cat antigen d1 Fel d 1) allergen and endotoxin content in settled house dust.
Exposure to Der f 1 and Der p 1 plus Der f 1 >10 µg·g−1 of mattress dust, respectively, increased the risk of wheeze and breathlessness (odds ratios (OR): 4.04, 95% confidence interval (CI): 1.53–10.64, OR: 2.78, 95% CI: 1.06–7.28). Fel d 1 >8 µg·g−1 was positively associated with cough at night (OR: 2.74, 95% CI: 1.22–6.17), noteworthy also in the nonsensitized subjects. Subjects exposed to elevated concentrations of more than one allergen had an up to seven-fold increase in the risk of respiratory symptoms, compared to nonexposed subjects. Sensitized subjects exposed to elevated concentrations of Der f 1 or Fel d 1 were found to have the highest risk of asthma attacks and respiratory symptoms. No statistically significant association was found between exposure to endotoxins and respiratory health.
Indoor exposure to Dermatophagoides farinae antigen 1 and cat antigen d1 is a risk factor for respiratory symptoms in adults, and for cat antigen d 1 even in nonsensitized subjects. The risk is increased if subjects are exposed to a mixture of allergens or if they are sensitized in addition to high exposure.
The prevalence of asthma and immunoglobulin-E (IgE)-mediated atopic diseases increased in many Western countries over recent decades 1. Inhalant allergens play a major role in the pathogenesis of allergic asthma and allergic rhinitis. Indoor allergens from house dust mites, cat dander, cockroaches, and fungi are of particular importance. The house dust mites Dermatophagoides pteronyssinus and D. farinae are the predominant sources of inhalant allergens in most parts of the world 2.
Which individual indoor allergen plays the major role, is a question of area-specific exposure to a single allergen or a mixture of several allergens. As mites cannot survive in very dry climatic conditions, exposure to mites does not play a major role in the development of allergic sensitization in dry climates 3. Cockroaches may be the predominant allergen exposure in USA inner cities 4, 5, but not in Germany 6.
There is increasing evidence for the impact of allergen exposure early in life on the development of allergic sensitization 7–9, but exposure to allergens later in life might be, at least in sensitized subjects, associated with the development of persistent inflammation in the airway wall, and consequently, with respiratory symptoms.
The aim of this paper was to study the relationship between asthma attacks and respiratory symptoms in adults and exposure to mite and cat allergen content in settled house dust. As allergen exposure constitutes only one element of the indoor environment, and differences in allergen levels could reflect overall differences in the indoor environment, the role of endotoxins was also studied. Furthermore, the effect of mixtures of several indoor allergens and interactions between indoor allergen exposure and allergic sensitization was analysed.
| Original language | English |
|---|---|
| Pages (from-to) | 555-563 |
| Journal | European Respiratory Journal |
| Volume | 18 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2001 |
| Externally published | Yes |