Allergen Content of Therapeutic Preparations for Allergen-Specific Immunotherapy of European Paper Wasp Venom Allergy.

Allergy to Polistes dominula (European paper wasp) venom is of particular relevance in Southern Europe, potentially becoming a threat in other regions in the near future, and can be effectively cured by venom immunotherapy (VIT). As allergen content in extracts may vary and have an impact on diagnostic and therapeutic approaches, the aim was to compare five therapeutic preparations for VIT of P. dominula venom allergy available in Spain. Products from five different suppliers were analyzed by SDS-PAGE and LC-MS/MS and compared with a reference venom sample. Three products with P. dominula venom and one product with a venom mixture of American Polistes species showed a comparable band pattern in SDS-PAGE as the reference sample and the bands of the major allergens phospholipase A1 and antigen 5 were assignable. The other product, which consists of a mixture of American Polistes species, exhibited the typical band pattern in one, but not in another sample from a second batch. All annotated P. dominula allergens were detected at comparable levels in LC-MS/MS analysis of products containing P. dominula venom. Due to a lack of genomic information on the American Polistes species, the remaining products were not analyzed by this method. The major Polistes allergens were present in comparable amounts in the majority, but not in all investigated samples of venom preparations for VIT of P. dominula venom allergy.

Evaluation and validation of a bee venom sting challenge performed by a micro-syringe.

BACKGROUND: The honeybee sting challenge is considered a reliable procedure to evaluate the efficacy of specific immunotherapy, but it is difficult and unpractical to perform in clinical practice, because live insects are required. OBJECTIVE: To assess the feasibility and reliability of a challenge test using a micro-syringe, and compared the procedure with sting challenge. METHODS: Patients on bee venom immunotherapy and without systemic reactions at field sting were enrolled. They underwent a sting challenge with live bee, and large local reactions were assessed up to 48 hours. Those patients displaying systemic reactions at the sting challenge were excluded from the syringe challenge for ethical reasons. The syringe challenge was done by injecting 0.5 µL fresh unfiltered bee venom at 2 mm depth (the length of the sting left by a bee). The same follow-up as at the first challenge was performed. Bee-specific immunoglobulin E (IgE) and tryptase were measured after each challenge. RESULTS: Nineteen patients underwent the sting challenge with live bees. Four had immediate systemic reactions (urticaria or asthma) and were excluded from the second challenge. The remaining 15 patients with large local reaction underwent the syringe challenge. No significant difference was seen in the maximum area of the large local reactions between the challenge with live bees and the syringe challenge. Also, no change was seen in tryptase and specific antibodies. CONCLUSION: This preliminary study suggests that the micro-syringe challenge with honeybee venom is feasible and produces results indistinguishable from those of the traditional sting challenge.

Sublingual immunotherapy for large local reactions caused by honeybee sting: a double-blind, placebo-controlled trial.

BACKGROUND: Sublingual immunotherapy (SLIT) proved effective and safe in respiratory allergy, and thus its use in hymenoptera allergy can be hypothesized. OBJECTIVE: We sought to assess, in a proof-of-concept study, whether SLIT might potentially be beneficial in hymenoptera allergy. The sting challenge in large local reactions (LLRs) was used to test this hypothesis. METHODS: We performed a randomized, double-blind, placebo-controlled study involving patients with LLRs who were monosensitized to honeybee. After the baseline sting challenge, they were randomized to either SLIT or placebo for 6 months. The treatment (Anallergo, Florence, Italy) involved a 6-week build-up period, followed by maintenance with 525 microg of venom monthly. The sting challenge was repeated after 6 months. RESULTS: Thirty patients (18 male patients; mean age, 44.5 years) were enrolled, and 26 completed the study, with 1 dropout in the active group and 3 dropouts in the placebo group. In the active group the median of the peak maximal diameter of the LLRs decreased from 20.5 to 8.5 cm (P = .014), whereas no change was seen in the placebo group (23.0 vs 20.5 cm, P = not significant). The diameter was reduced more than 50% in 57% of patients. One case of generalized urticaria occurred in a placebo-treated patient at sting challenge. No adverse event caused by SLIT was reported. CONCLUSION: Honeybee SLIT significantly reduced the extent of LLRs, and its safety profile was good. Although LLRs are not an indication for immunotherapy, this proof-of-concept study suggests that SLIT in hymenoptera allergy deserves further investigation. Trials involving systemic reactions and dose-ranging studies are needed.