FEATHER MITES ARE POTENTIALLY AN IMPORTANT SOURCE OF ALLERGENS FOR PIGEON AND BUDGERIGAR KEEPERS

Background Previous studies on allergy to feathers have not addressed whether organisms living on feathers (mites, lice, moulds) are a sourc e of allergens. Objective To investigate whether feather mites produce d allergens of clinical relevance to bird keepers. Methods We examined serum IgE responses of 96 pigeon breeders to an extract of feather mi tes from pigeons (predominantly Diplaegidia columbae), using Western b lotting, specific IgE assay using AlaSTAT EIA and RAST inhibition. Res ults Feather mites are a major source of soluble proteins derived from feathers, accounting for up to 10% of the total weight of the feather . Forty-three sera had a negative score (0) for anti-feather mite IgE, 27 were weakly positive (1-2) and 26 had strongly positive scores (3- 4). Fewer pigeon breeders with scores greater than or equal to 3 were asymptomatic than those with negative scores (12 versus 40%), more had late onset symptoms (with or without early onset symptoms; 77% versus 44%) and had IgE antibody against house dust mite (89% versus 23%). W estern blotting of eight sera against the extract of Diplaegidia colum bae revealed 20 IgE-binding components ranging from 22 to 200 kDa. A h igh diversity of components was recognized by each serum: arithmetic m ean 7 (range 2-14). RAST inhibition indicated feather mites had specie s-specific epitopes as well as ones that cross-reacted with Dermatopha goides pteronyssinus. Conclusion Strongly-positive AlaSTAT scores to p igeon feather mite were associated with allergic symptoms of late onse t in pigeon breeders. We conclude that feather mites are a major sourc e of clinically-relevant allergens for pigeon breeders.