RESUMO
BACKGROUND: We report a 31-year-old farmer whose work consists in handling cereal and vegetables, who consulted our clinic because of asthma symptoms after inhalation of dust during manipulation of the deposited material, usually inside the warehouse. METHODS AND RESULTS: Skin prick tests and specific immunoglobulin E (IgE) determinations were negative with common aeroallergens. The patient noted the presence of many spiders in the warehouse, which were identified as the cellar spider Holocnemus pluchei and the common house spider, Tegenaria domestica. Extracts of spider bodies brought in by the patient were obtained and used to perform in vivo and in vitro studies. Molecular characterization of IgE-binding bands was performed by mass spectrometry. We obtained positive prick tests to the extracts of the bodies of both spiders. Immunoblotting displayed different bands in both spider extracts, in a range of 20-70 kDa. All were hemocyanins, except for a 17-kDa protein of Holocnemus identified as an arginine kinase (AK). Bronchial challenge was positive with the extract of the cellar spider and with the AK, but was negative with the domestic house spider. CONCLUSION: We present the first case of respiratory allergy due to sensitization to AK from a common spider, confirmed by bronchial provocation tests.