Fax +41 61 306 12 34 E-Mail karger@karger.ch www.karger.com Original Paper Int Arch Allergy Immunol 2007;143:92–102 DOI: 10.1159/000098657 Severe Immediate Allergic Reactions to Grapes: Part of a Lipid Transfer Protein-Associated Clinical Syndrome Emilia Vassilopoulou a Laurian Zuidmeer b Jaap Akkerdaas b Ioannis Tassios a Neil R. Rigby c E.N. Clare Mills c Ronald van Ree b Photini Saxoni-Papageorgiou a Nikolaos G. Papadopoulos a a Allergy Research Centre, Second Pediatric Clinic, University of Athens, Athens, Greece; b Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands; c Institute of Food Research, Norwich Research Park, Colney, UK sensitised to grape LTP. A 28-kDa expansin, a 37.5-kDa poly- galacturonase-inhibiting protein, a 39-kDa -1,3-glucanase and a 60-kDa protein were identified as minor grape aller- gens. Endochitinase and TLP did not play a role. Inhibition experiments revealed the possible cross-reactive role of LTP for clinical sensitivities to other LTP-containing plant foods, but also the involvement of cross-reactive carbohydrate de- terminants of minor allergens in IgE cross-reactivity. Conclu- sions: LTP is the major grape allergen, while additional mi- nor allergens may contribute to clinical reactivity. Severe grape allergy presents in atopic patients who frequently re- act to other LTP-containing, plant-derived foods. The ‘LTP syndrome’ is the appropriate term to describe this condi- tion. Copyright © 2007 S. Karger AG, Basel Introduction Grapes (species Vitis vinifera ) belong to the Vitaceae family and are widely cultivated and consumed all over the world as fresh fruits and processed foods, such as juic- es and wine. In Greece, grape cultivation takes part dur- ing February and June when the first cultivars are mature Key Words Carbohydrate determinants  Cross-reactivity  Digestion  Expansin  Grape allergens  IgE  Lipid transfer protein  Polygalacturonase-inhibiting protein  -1,3-Glucanase Abstract Background: Grape allergy is considered rare; grape lipid transfer protein (LTP; Vit v 1), an endochitinase and a thau- matin-like protein (TLP) have been reported as grape aller- gens. A considerable number of patients have referred to our department for severe reactions to grapes, and several IgE binding proteins were detected. Objectives: The aim of this study was to identify and characterise the allergens involved in severe allergic reactions to grapes and describe the popu- lation in which they occur. Methods: Patients with reported severe allergic reactions to grapes (n = 37) are described. Grape allergens were purified/fractionated by a combina- tion of chromatographic techniques, identified by proteomic analysis and biochemically characterised. Immunoreactivity was assessed by blot (inhibitions) and RAST (inhibitions), and skin prick tests were performed with the isolated allergens. Results: All subjects were polyallergic, sensitised and reac- tive to several additional foods and pollen. All patients were Received: June 9, 2006 Accepted after revision: October 5, 2006 Published online: January 15, 2007 Correspondence to: Dr. Emilia Vassilopoulou Allergy Research Centre Fidippidou Street 41 GR–11527 Goudi (Greece) Tel./Fax +30 210 777 6964, E-Mail emi@allergy.gr © 2007 S. Karger AG, Basel 1018–2438/07/1432–0092$23.50/0 Accessible online at: www.karger.com/iaa