Anaphylaxis to apple: is fasting a risk factor for LTP-allergic patients?
BACKGROUND
Primary apple allergy is frequent in Mediterranean countries where hypersensitivity to lipid transfer protein (LTP) is common. Due to its stability upon pepsin digestion, LTP may cause systemic allergic reactions. This study investigated the potential risk associated with an isolated intake of apple while fasting in LTP-hypersensitive patients with clinical allergy to peach but not to apple.


METHODS
Based on the observation of 6 patients who experienced 7 apple-induced anaphylactic reactions that in 6 cases followed the ingestion of the fruit after fasting, open food challenges were carried out in 12 patients LTP-hypersensitive patients with peach allergy but tolerant to apple.


RESULTS
Four out of the 12 patients (33%) reacted to apple upon oral challenge.


CONCLUSIONS
Fasting seems to play a relevant role in the clinical expression of allergy to LTP. It is possible that in an empty gastrointestinal tract the allergen is absorbed more rapidly. Alternatively, pepsin might digest the food matrix more efficiently, thus increasing the concentration of the purified allergen that comes in contact with the gut mucosa.
Ambulatorio di Allergologia, Azienda Sanitaria Provinciale di Messina.
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Arena
D000328:Adult; D000485:Allergens / Q000276:immunology; D000707:Anaphylaxis / Q000178:diet therapy / Q000453:epidemiology* / Q000276:immunology* / Q000503:physiopathology; D052179:Antigens, Plant / Q000276:immunology; D002352:Carrier Proteins / Q000276:immunology; D005215:Fasting; D005260:Female; D005512:Food Hypersensitivity / Q000178:diet therapy* / Q000453:epidemiology* / Q000276:immunology / Q000503:physiopathology; D005638:Fruit / Q000009:adverse effects; D006801:Humans; D007114:Immunization; D008297:Male; D027845:Malus / Q000276:immunology*; D008875:Middle Aged; D010940:Plant Proteins / Q000276:immunology; D027861:Prunus / Q000276:immunology; D012307:Risk Factors
D000485:Allergens; D052179:Antigens, Plant; D002352:Carrier Proteins; D010940:Plant Proteins; C511920:lipid transfer proteins, plant