Preliminary

Laboratory markers of mast cell and basophil activation in monitoring rush immunotherapy in bee venom-allergic children Mediators of mast cells and basophils are con-sidered to be interesting as potential markers of anaphylaxis that could be useful in both diagnosis of venom allergy and monitoring venom immunotherapy (VIT). In adults, elevated baseline serum tryptase was recently indicated as a potential predictor of severe post-sting reactions, as well as a marker suitable for monitoring the safety of VIT [1,2]. Urinary 9a,11b-PGF2, a metabolite related to mast cell activation, was previously suggested by Ono et al. as a sensitive marker of anaphylac-tic reaction [3]. Bochenek et al. suggested that in asthmatic adults, plasma 9a,11b-PGF2 may be more sensitive than urine measurements in detecting mast cell activation during bronchial challenge with allergens [4]. Flow-assisted mon-itoring of basophil activation proved helpful in detecting hymenoptera venom allergy – even in IgE-negative cases and in predicting the side effects during VIT [5]. The aim of the present study was to analyze levels of mast cell acti-vation markers (tryptase and 9a,11b-PGF2) and basophil activation markers (peripheral blood basophil count and CD63 expression) in honeybee venom-allergic children undergoing initial rush VIT and the subsequent 1-month maintenance immunotherapy. Patients & methods Five patients: four boys and one girl aged from 9.5 to 18 years with history of systemic reactions after honeybee stings participated in the study. The patients were qualified for honeybee venom (BV)-specific immunotherapy based on the fol-lowing criteria: history of severe systemic reac-tions (Mueller’s grade III or IV) after honeybee stings; confirmed IgE-mediated hypersensitiv-ity to BV (positive skin tests or specific IgE); and lack of skin symptoms of mastocytosis. Informed consent was obtained from the chil-dren’s guardians following recommendations of the local bioethics body. Clinical characteristics of the patients along with results of allergy tests are shown in Table 1. The study covered 40 initial days of immunotherapy, including the 5-day rush build-up phase with cumulative dose o