Allergenicity of the mite Hemisarcoptes corremani

Background: A researcher experienced allergic symptoms while working with t he astigmatid mite Hemisarcoptes cooremani cultured on scale insects. This mite is a predator of scale insects that often parasitize many perennial va scular plants in orchards, gardens, and ornamental nurseries worldwide; the refore, orchard and ornamental nursery workers and gardeners may be exposed to this mite. Objective: We investigated the possible allergenicity of H. cooremnni and t he cross-reactivity between it and other allergy-causing astigmatid mites. Methods: Serum from a subject who experienced allergic symptoms while worki ng with H. cooremani was analyzed for IgE and IgG to proteins in an extract of this mite and of other astigmatid mites known to cause allergic reactio ns. The serum was used to probe proteins fractionated by SDS-PAGE or precip itated by CIE using rabbit antiserum. In addition, the subject's serum was used to directly precipitate proteins in extracts of H. cooremani and other mite species. Results: SDS-PAGE and immunoblotting of proteins in an H. cooremani extract showed the reference serum contained IgE directed at 16-kD and 19-kD prote ins. Crossed radioimmunoelectrophoresis reaction showed that the subject's serum contained antibody that precipitated a protein in an H. cooremani ext ract and that IgE bound to this protein. The proteins in an extract of H. c ooremani did not precipitate when reacted with rabbit antisera against the dust mites D. farinae, D. pteronyssinus, and E. maynei, or the storage mite s B. tropicalis, L. destructor, and T. putrescentiae. This indicated there was no cross-reactivity between H. cooremani and these mites. Conclusion: These results indicated that an extract of the mite H. cooreman i contained at least two prominent IgE binding proteins that were not prese nt in the other astigmatid mites. Thus, H. cooremani is the source of uniqu e allergenic proteins and allergy to this mite may develop in orchard and o rnamental nursery workers and gardeners.