Assay for the major dog allergen, Can f I: investigation of house dust samples and commercial dog extracts

Quantification of a major bovine allergen by a two-site immunometric assay based on monoclonal antibodies

A two-site immunometric assay based on monoclonal antibodies (mAb) was developed for the measurement of a 20-kDa major allergen of cow. The sensitivity of this assay was (BDA20) 1 ng/ml. It was used to measure airborne allergen concentrations in 10 Finnish cowsheds. The mean concentration of the BDA20 measured at two stationary sites was 280 ng/m3. Concentrations varied more than 10-fold among cowsheds (54-804 ng/m3). The mean intertest coefficient of variation was 8.2%, and the mean intratest variation 4.1%.

Cat (Fel d I), dog (Can f I), and cockroach allergens in homes of asthmatic children from three climatic zones in Sweden

We have investigated the levels of cat (Fel d I), dog (Can f I), and cockroach (Per a I) allergens in dust from bedrooms, living rooms, kitchens, and bathrooms from 123 homes of asthmatic children in three zones of Sweden with varying climates. Absolute indoor humidity (AIH), relative humidity (RH), rate of ventilation in air changes per hour (ach), and number of airborne particles were also measured. Fel d I, Can f I, and Per a I allergen contents were determined by mab ELISA, and the levels were related to various environmental factors. The major cat allergen, Fel d I, was detected in all homes, and the concentrations varied between 16 ng and 28,000 ng/g fine dust. The dog allergen, Can f I, was detected in 85% of the homes, and the levels varied from 60 ng to 866,000 ng/g dust. Cockroach allergen was detected in only one home (40 ng/g). Fel d I and Can f I allergens were equally distributed geographically. Dust from living rooms contained significantly higher (P < 0.05) concentrations of both Fel d I and Can f I allergens than dust from bedrooms, kitchens, and bathrooms. The levels tended to be higher in homes with poor ventilation (< 0.5 ach) and in homes with wall-to-wall carpets. Significantly higher (P < 0.01) numbers of airborne particles were found in homes with high humidity (i.e., AIH > or = 7 g/kg or RH > or = 45%).(ABSTRACT TRUNCATED AT 250 WORDS)

Indirect contact with pets can confound the effect of cleaning procedures for reduction of animal allergen levels in house dust

To investigate the capacity of common vacuum cleaners and chemical treatment to reduce cat (Fel d I) and dog (Can f I) allergen content in house dust, 52 families with allergic children and no pets at home were recruited. Five groups of 10-11 families used their central vacuum cleaners (n = 10), their own old vacuum cleaners plus either tannic acid (n = 10) or placebo (n = 10) applied to carpets and upholstry after the first sample was collected on Day 0 or new vacuum cleaners equipped with either HEPA (high efficiency particulate air)- (n = 11) or microfilters (n = 10). Dust samples were collected from carpets and upholstered furniture in the living rooms and from the mattresses of the children on Days 0, 7, 21, and 35. Fel d I and Can f I allergens were determined by sandwich ELISA methods. Central, micro-filter and HEPA-filter vacuum cleaners did not reduce the concentrations nor the total amount/sampling area of Fel d I or Can f I. Tannic acid initially reduced (p < 0.05) both the concentration and the total amount of Fel d I by 30% and Can f I by 10%, but only for one week. The levels increased to base-line after 21-35 days. The concentrations of Fel d I increased 10-30 times in homes visited by cats or cat owners. We conclude, that tannic acid treatment reduced pet allergen concentrations and total amounts in dust for one week only.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens and asthma

This article presents the studies that show that asthma in children is strongly associated with sensitization to dust mite and other indoor allergens. In addition, the recent evidence that this association reflects a causal relationship between allergen exposure and asthma is reviewed. The relevance of quantitative measurements of the major indoor allergens (dust mite, cockroach, and cat) in the houses of children with asthma is discussed. Finally, the increasing evidence that avoidance measures can be an effective treatment for asthma is considered together with the details about avoidance protocol for dust mite and cat allergen.