after arrest means that he had gone through 3 half lives and that the mast cell tryptase at time of arrest could have been 200 lg/l, which would be diagnostic of death due to anaphylactic shock. C. Phelan Central Path Lab University Hospital of North Staffordshire Hartshill, Stoke-on-Trent ST4 7LN UK Tel.: +44 (0) 01782 554409 Fax +44 (0) 01782 554664 Accepted for publication 9 April 2007 Allergy 2007: 62:965–966 Ó 2007 The Authors Journal compilation Ó 2007 Blackwell Munksgaard DOI: 10.1111/j.1398-9995.2007.01423.x Reference 1. Perez-Calderon R, Gonzalo-Garijo MA. Anaphylaxis due to loperamide. Allergy 2004;59:369. Treatment with American Polistes venom was ineffective in an Italian patient allergic to European Polistes P. Bonadonna, B. Caruso, D. Labardi, A. Dama, G. Senna, G. Passalacqua* Key words: cross-reactivity; immunoblotting; Polistes dominulus. Polistes is the most common genus of social wasps. The species Polistes domi- nulus (PD), Pol- istes gallicus and, to a lesser extent, Polistes nymphus are largely dif- fused in Europe (1), with a great- er distribution in the Mediterra- nean areas (Italy, Greece, Spain, France and North Africa). PD is also present around the Caspian Sea and across Russia and China (2). Until 1996, when Anallergo (Florence, Italy) started the production of PD venom, only a mixture of the American Polistes (AP) species was commercially available for diagnosis and therapy. Of note, the American species are not pre- sent in Europe and recent studies (3, 4) show that American and European spe- cies of Polistes are phylogenetically dis- tant. We describe the case of a patient for whom immunotherapy with AP extract was ineffective due to the poor cross- reactivity with PD venom. The patient is a 39-year-old woman, who 7 years ago developed a severe grade 4 allergic reaction following hymenoptera sting. She had asthma, urticaria and hypotension and was therefore treated with adrenaline at the emergency department. The insect could not be directly identified, but it was supposed to be a wasp, due to the absence of the sting in the skin lesion. Intradermal tests, performed with commercial extracts (Stallergenes, Milan, Italy) gave a strongly positive reaction to AP mix (0.1 lg/ml) and a mild reaction to vesp- ula venom (1.0 lg/ml), whereas honeybee venom was negative. Specific IgE (CAP test, Pharmacia & Upjohn Diagnostic, Uppsala, Sweden) were 2.61 kU/l for AP and negative for vespula and honeybee. Based on these results, immunotherapy with an AP extract (Stallergenes) was started and a maintenance dose of 100 lg was reached in 7 weeks. After 4 years the patient was stung again by a wasp, perhaps a Polistes, with subsequent grade III reaction (urticaria, angioedema and asthma). At this point, the diagnostic workup was repeated, including also the newly available PD extract. The intradermal test was strongly positive for PD (0.1 lg/ml) and negative for bee and vespula. Specific immuno- globulin (Ig) E were 4.94 kU/l for PD, 1.93 kU/l for AP and negative for vesp- ula and bee. We carried out a CAP-inhibition assay, according to Straumann and slightly modified (5), in order to assess the cross- reactivity between PD and AP mix. The patientÕs serum was incubated overnight either with PD venom or AP mix, then IgE against PD and AP were measured. After incubation with AP extract, the AP-specific IgE were reduced, as expec- ted, by 74% and the same happened for PD-specific IgE after incubation with PD venom (77%). On the contrary, after incubation with AP mix, the PD-specific IgE were reduced only by 39%. The protein components of PD venom (5 or 20 lg/lane) were resolved via sodium dodecyl sulphate polyacrylamide gel electrophoresis (Bio-Rad, Hercules, CA, Diagnostic and therapeutic extracts for European and American Polistes are only partially cross- reactive Figure 1. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot- ting experiments. (A) SDS-PAGE: protein separation of PD venom, Vespula germanica venom and Cupressus extract, against standard molecular weights (MW); (B) immunoblotting: patientÕs immuno- globulin (Ig) E recognizing Pol d 1 (phospholipase PD), Pol d 2 (hyaluronidase PD), Pol d 5 (antigen 5 PD), Ves g 1 (phospholipase V. germanica); no IgE against Cupressus; Pol d 2 and Pol d 5 are recognized only at the highest concentration of venom. (C) Immunoblotting: total inhibition of patientÕs IgE for PD and Vg after incubation with PD venom. ALLERGY Net 966