IGE CROSS-REACTIVITIES AGAINST ALBUMINS IN PATIENTS ALLERGIC TO ANIMALS

Background: Type I allergic symptoms and severe asthma in particular a re frequently caused by animal hair/dander proteins, among which album ins are possible cross-sensitizing allergenic components. Methods: The significance and degree of IgE-cross-reactivities against various alb umins were studied in a representative number (n = 200) of patients al lergic to animals with hair/dander extracts, purified albumins from di fferent animals, and a recombinant dog albumin fragment expressed in l ysogenic Escherichia coli Y1089 and purified as a beta-galactosidase f usion protein. Results: Despite a high degree of sequence homology amo ng different albumins, a remarkable variability of IgE cross-reactivit ies was observed, indicating that some patients were sensitized prefer entially against certain albumins. Most of the patients allergic to al bumins, however, reacted to dog, cat, and horse albumin, which also bo und a high percentage of albumin-specific IgE. Conclusion: The purifie d recombinant dog albumin fragment, representing 265 amino acids of th e mature protein, bound IgE from all 15 patients allergic to albumin t ested suggesting its potential usefulness for diagnosis and perhaps th erapy.