A novel inhalation allergen present in the working environment of beekeepers

Background:  Inhalation allergies, caused by allergens from various kinds of pollen, house dust mites, animal epithelium, and mould fungi, are strongly increasing in frequency. In 2.6% of the cases the allergen source remains unidentified. The present paper describes a so far unknown inhalation allergy which was observed in the case of a patient working with hives. Methods and results:  The allergen was characterized by immunoblotting, enzyme-linked immunosorbent assay inhibition, and isoelectrofocusing, using the serum of the patient. It is present in both the bee bodies and the larvae, has a molecular mass of 13 kDa, and an isoelectric point of 5.85. It is thermolabile and does not cross-react with allergens from birch, mugwort and timothy grass pollen, mould fungi, or bee venom. The N-terminal amino acid sequence of allergen from larvae was determined to be 2QIEELKTRLHT12. A similar allergen of 13 kDa was also found in Varroa mite accompanying bee populations. Conclusion:  Honey bees (including the larva stadium) and Varroa mite contain a 13-kDa protein causing an allergic reaction. Presently, there is no evidence whether the case described is a singular phenomenon or whether this allergen is a more common inducer of allergies among subjects exposed to honey bees. However, a bee and Varroa mite allergy has to be considered for beekeepers after exclusion of known inhalation allergies.