[Importance of animal epithelia as house dust allergens]

Area of Science:

• Allergy and Immunology
• Environmental Health

Background:

• House dust allergy is a common condition, often attributed to house dust mites.
• The specific allergens responsible for positive house dust radio-allergosorbent tests (RAST) require further elucidation.

Purpose of the Study:

• To investigate the role of various allergens, particularly animal epithelia, in positive house dust RAST reactions.
• To determine if sensitization to cat epithelia contributes to house dust allergy.

Main Methods:

• Radio-allergosorbent test (RAST) was used to test sera from 379 atopic patients for reactivity to domestic dust and house dust mites.
• Sera negative for house dust mites were further tested for specific IgE against cat, dog, guinea-pig, horse, and cattle epithelia, and cockroaches.
• Immune-adsorption studies were performed using cat epithelia to assess its impact on house dust RAST levels.

Main Results:

• 130 patients showed positive RAST for both house dust and house dust mites.
• Of sera negative for house dust mites, 89.5% reacted positively to at least one animal epithelium, with cat epithelia being particularly significant.
• Adsorption with cat epithelia significantly inhibited house dust RAST levels (60-80%), while other animal epithelia did not.

Conclusions:

• Sensitization to cat epithelia is a significant cause of positive house dust RAST reactions, independent of house dust mite allergy.
• Cat epithelia should be considered a crucial allergen in patients with suspected house dust inhalation allergies.
• These findings underscore the complexity of house dust allergy and the need for comprehensive allergen testing.