An extract of dust from the air-vent filters of a room housing guinea pigs was analysed by quantitative immunoelectrophoretic procedures and compared with extracts of various materials derived from guinea pigs. Crossed radio-immunoelectrophoresis (CRIE) of the dust, performed with sera from twenty asthmatic patients who were positive by skin testing and RAST to guinea pig extracts, identified fourteen IgE-binding constituents. Although responses varied, most sera reacted with lour particular allergens, antigens 2. 3, 10 and SI. The numbers of allergens recognized by individual patients correlated with the RAST score, but not with total scrum IgE.
All seventeen dust constituents detected by crossed immunoelectrophoresis (and all four major allergens), were also present in extracts of guinea pig dander, fur. saliva and urine; several of these components were absent in an epithelial extract, and there were even less in preparations of shaved pelt, serum or faeces. None of the dust extract antigens were detected in materials used in animal husbandry, dust samples from rooms without guinea pigs, or a D. pteronyssinus extract. These findings suggest that inhalant allergens may be derived predominantly from material shed from the guinea pig coat after contamination with saliva, and possibly to a lesser extent, urine.