Standardization of animal epithelia.

The standardization of animal epithelia is warranted for an accurate diagnosis and safe and efficacious treatment of allergic respiratory diseases induced by the inhalation of mammalian aeroallergens. We have compared several sources of raw materials of cat, hamster, goat and rabbit hair and epithelia to establish differences between the protein and allergenic composition of these extracts. The main differences in these raw materials was that "epithelia" were supplied as a mixture of hair and epithelia previously treated with acetone, and that the hair was supplied and used untreated. A possible influence of the age of rabbits on the composition of rabbit hair extracts was also evaluated. Overall, important differences were detected in the composition of epithelia versus hair extracts. Epithelia extracts contained more irrelevant proteins and, in most cases, less amounts of major allergens. Important differences were also detected in the composition of the extracts prepared with hair of young versus adult animals. In general, the extracts derived from young animals contained less major allergen and more albumin than those derived from older animals. A greater effort should be made to identify the ideal sources of animal skin derived allergen extracts to provide the allergologists with better extracts for the diagnosis and treatment of allergic respiratory diseases. There is also a need for a consensus on the terminology applied to animal skin derived extracts. The use of the term dander extracts seems to be more appropriate. These extracts contain more relevant allergens and fewer albumins.