Severe immediate allergic reactions to grapes: part of a lipid transfer protein-associated clinical syndrome.
BACKGROUND
Grape allergy is considered rare; grape lipid transfer protein (LTP; Vit v 1), an endochitinase and a thaumatin-like protein (TLP) have been reported as grape allergens. A considerable number of patients have referred to our department for severe reactions to grapes, and several IgE binding proteins were detected.


OBJECTIVE
The aim of this study was to identify and characterise the allergens involved in severe allergic reactions to grapes and describe the population in which they occur.


METHODS
Patients with reported severe allergic reactions to grapes (n = 37) are described. Grape allergens were purified/fractionated by a combination 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 reactive to several additional foods and pollen. All patients were sensitised to grape LTP. A 28-kDa expansin, a 37.5-kDa polygalacturonase-inhibiting protein, a 39-kDa beta-1,3-glucanase and a 60-kDa protein were identified as minor grape allergens. 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 determinants of minor allergens in IgE cross-reactivity.


CONCLUSIONS
LTP is the major grape allergen, while additional minor allergens may contribute to clinical reactivity. Severe grape allergy presents in atopic patients who frequently react to other LTP-containing, plant-derived foods. The 'LTP syndrome' is the appropriate term to describe this condition.
Vassilopoulou
Emilia
E
Allergy Research Centre, Second Pediatric Clinic, University of Athens, Athens, Greece. emi@allergy.gr
Zuidmeer
Laurian
L
Akkerdaas
Jaap
J
Tassios
Ioannis
I
Rigby
Neil R
NR
Mills
E N Clare
EN
van Ree
Ronald
R
Saxoni-Papageorgiou
Photini
P
Papadopoulos
Nikolaos G
NG
D000293:Adolescent; D000328:Adult; D052179:Antigens, Plant / Q000276:immunology*; D015153:Blotting, Western; D002352:Carrier Proteins / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology*; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000276:immunology*; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D040901:Proteomics; D011852:Radioallergosorbent Test; D027843:Vitis / Q000737:chemistry / Q000276:immunology*
D052179:Antigens, Plant; D002352:Carrier Proteins; C030363:lipid transfer protein; D007073:Immunoglobulin E