Vespa velutina nigrithorax venom allergy: inhibition studies approach for the choice of specific immunotherapy.

Summary: Vespa velutina nigrithorax (VVN), commonly known as Asian wasp because endemic in Asia, represents an alien species in Europe. VVN can induce allergic reactions similar to those caused by other Hymenoptera and death after VVN stings, presumably due to fatal allergic reactions, has been reported. In the treatment of Hymenoptera venom hypersensitivity, specific immunotherapy (VIT) is highly effective. Currently, there is no specific available VIT for VVN, so it is relevant to assess if patients stung by VVN and showing allergic reactions could be treated with the Hymenoptera commercially available extracts Vespa crabro (VC) and Vespula spp (Vspp) or if they need the specific VIT with VVN venom extract. Methods. Four patients with a clinical history of systemic reactions after VVN sting were evaluated. Serum specific IgE were assayed quantitatively with an automated fluoro-enzyme immunoassay ImmunoCAP™ Specific IgE by Phadia™ 1000 System (Thermo Fisher Scientific, Uppsala, Sweden) for VC, Vspp and VVN. Cap inhibition assays were performed incubating serum samples with 200 µl of each venom at increasing concentrations and subsequently specific IgE against each of the venoms were determined in the samples by Phadia™ 250 System (Thermo Fisher Scientific, Uppsala, Sweden). Results. Our results suggested that both Vspp and VC venoms were able to inhibit the specific IgE for VVN, although the VC compared to the Vspp venom showed a higher inhibition. Conclusions. Our inhibition studies suggested that VIT with VC venom, nowadays when there is not specific available VIT for VVN, may be more effective than Vspp VIT in patients with VVN sting reactions.

Allergy to Parietaria pollen and month of birth.

It has been suggested that the season of birth is a predisposing factor for allergic sensitization. In the last few years many authors in different countries have found a statistically significant correlation between the month of birth and the subsequent allergy for grasses and birch pollens and house dust mites. Nevertheless, other investigators failed to confirm these results. The aim of the present study is to assess the relationship between the season of birth and the development of respiratory allergy to pollen of Parietaria, an Urticacea plant characteristic of Mediterranean flora, which is the most important hay fever producing one in our country. Among the patients who visited the Servizio Autonomo di Allergologia at the St. Martino Hospital (Genoa, Italy) in the year 1986, 264 subjects (113 F and 151 M, 5-35 years of age, all born and living in Genoa and its suburbs) were selected. The birth month of these patients, affected by rhinitis and/or bronchial asthma and with positive prick-test only toward Parietaria pollen, was recorded and compared with that of the population born in Genoa in the same years. Statistical evaluation made by X2 test showed the absence of a statistically significant relationship between the birth in the pollen season (April-July) and the pollinosis, with the exception of the month of May. The reasons of the discrepances observed between the behaviour of Parietaria pollen and that of the other pollens, grasses and birch, described in the above studies, are discussed.