Exercise-induced anaphylaxis to grape G. Senna, G. Mistrello, D. Roncarolo, M. Crivellaro, P. Bonadonna, M. Schiappoli, G. Passalacqua* Key words: exercise-induced anaphylaxis; food allergy; grape. . EXERCISE-induced anaphylaxis (EIA) is characterized by airways obstruction urticaria, and hypotension following physical exercise, and it can be associated with food allergy (1, 2). We describe one case of EIA due to ingestion of grape, which rarely causes allergic reactions. A 33-year-old woman, with allergic rhinoconjunctivitis due to Parietaria and mugwort, reported in the past year facial flushing, edema of the lips, and dyspnea after drinking white or red wine, although she could eat fresh grapes without problem. The symptoms were reproducible and clearly related to wine; therefore, she was advised to avoid it. One month before, after eating white grapes, she had gone jogging. After the exercise, urticaria, facial/ pharyngeal edema, abdominal pain, and dyspnea appeared and rapidly worsened. At the emergency department, profound hypotension was found: her blood pressure was 70/52 mmHg, heart rate 130 bpm, and respiratory frequency 24/min. She received epinephrine, plasma expanders, and corticosteroids/antihistamines, and recovered within 3 h. We suspected EIA associated with grape allergy, and performed a detailed diagnostic procedure. The skin prick tests with commercial extracts (Stallerge `nes, Antony Cedex, France) with inhalants and foods were negative except for Parietaria and mugwort. Molds (Aspergillus fumigatus, Cladosporium herbarum, Alternaria alternata, Penicillium notatum, and Botrytis), which can be present on grape surfaces, were negative as well. The prick-to-prick tests with juice from white and red grapes were positive. The arithmetic means of wheal diameters were as follows: 8 mm for white grape, 5 mm for red grape, and 4 mm for histamine HCl 0.1%. The oral single-blind challenge with metabisulfite using increasing doses up to 75 mg (Test Dose, Lofarma, Milan, Italy) was negative. An in vivo challenge (food plus exercise) was not performed for ethical reasons. Serum tryptase (Tryptase UniCAP, Pharmacia, Uppsala, Sweden) in a blood sample obtained within 1 h after the onset of EIA was increased (18.2 ng/ml, normal value ,15 ng/ml). A grape extract was prepared for immunologic studies. Grape was homogenized and extracted at 10% w/v in 0.1 M potassium phosphate buffer, pH 7, for 1 h. After removing the particulate by centrifugation, the supernatant was dialyzed against 5 mM ammonium bicarbonate, lyophilized, and resuspended in 1/10 of the initial volume. Electrophoresis of the extract (12 mg/lane) was performed in a 10% polyacrylamide gel (Nupage Sis-Tris, Prodotti Gianni, Milan, Italy) at 180 mA for 1 h. The resolved proteins were stained with 0.1% Coomassie brilliant blue and transferred to a nitrocellulose membrane (Protann BA, 85, Scheicher and Schuell, Milan, Italy). The membrane was saturated with 5% defatted dried milk before incubation with patient’s serum or control sera diluted 1:2. Bound specific IgE was then detected by peroxidase-conjugated antihuman IgE serum. No grape-specific IgE could be demonstrated in the patient’s serum by the CAP-RAST technique. However, the assessment of IgE reactivity of serum against grape extract provided a positive result. The SDS–PAGE profile of grape extract showed the presence of a well-resolved band at about 67 kDa and a diffuse stain between 25 and 35 kDa. Immunoblotting showed that the patient’s serum had IgE antibodies against one specific component of the extract (approximate molecular mass 30 kDa), whereas control sera also reacted to the 67- kDa band. IgE-mediated reactions to grape have been rarely reported (2, 3–6). The case herein described was a true food-associated EIA, since the patient remained asymptomatic when eating at rest great amounts of the sensitizing food. The prick-to-prick positivity and the increase of serum tryptase confirmed the mast-cell activation. Moreover, the immunoblot analysis suggested that the patient had specific IgE reacting to one component of the grape extract, despite the negativity of the CAP- RAST assay. *Allergy and Repiratory Diseases, DIMI Pad. Maragliano L.go R.Benzi 10 16132 Genoa Italy Tel. +390103538908 Fax: +390103538904 E-mail: gpass@smartino.ge.it Accepted for publication 7 August 2001 Allergy 2001: 56:1235–1236 Copyright # Munksgaard 2001 ISSN 0105-4538 References 1. SHEFFER AL, TONG AKF, MURPHY GF, LEWIS RA, MCFADDEN ER Jr, AUSTEN KF. Exercise-induced anaphylaxis: a serious form of physical allergy associated with mast-cell degranulation. J Allergy Clin Immunol 1985;75:479–484. 2. OKAZAKI M, KITANI H, MIFUNE T, et al. Food-dependent exercise induced anaphylaxis. Intern Med 1992;31:1052–1055. 3. DOHI M, SOKO M, SUGIJAMA H, et al. Food dependent exercise induced anaphylaxis: a study on 11 Japanese cases. J Allergy Clin Immunol 1991;87:34–40. 4. BIRCHER AJ, BIGLIARDI P, YILMAZ B. Anaphylaxis resulting from selective sensitization to American grapes. J Allergy Clin Immunol 1999;104:1111–1112. EIA based on IgE- mediated Parietaria and mugwort allergy. 1235