Allergy to jackfruit: a novel example of Bet v 1-related food allergy.
BACKGROUND
Jackfruit allergy has been reported just once. It is unknown whether this food allergy is caused by direct sensitization or cross-sensitization to pollen allergens.


OBJECTIVE
Establish whether jackfruit allergy is linked to birchpollen allergy.


METHODS
Two jackfruit allergic patients and five patients with birchpollen-related apple allergy were recruited. Sensitization to pollen and plant foods was assessed by skin prick test (SPT), radio-allergosorbent test (RAST) and immunoblot. RAST analysis was performed for Bet v 1 and Mal d 1. Cross-reactivity was evaluated by RAST and immunoblot-inhibition. Biological activity of immunoglobulin E (IgE) was measured by basophil histamine release. Allergy to jackfruit was evaluated by double-blind placebo-controlled food challenge (DBPCFC) or open challenge (OC).


RESULTS
In both patients DBPCFC confirmed the reported jackfruit allergy. SPT was 41 and 27 mm2 and specific IgE to jackfruit was 5.9 and 0.8 IU/ml, respectively. Immunoblot analysis revealed IgE reactivity at Mr of approximately 17 kDa. The Bet v 1-related nature of this allergen in jackfruit was demonstrated by RAST and immunoblot inhibition. To assess whether jackfruit allergy might be common in patients with combined birchpollen-fruit allergy, five such patients underwent an OC with jackfruit. All five had OA-like symptoms.


CONCLUSIONS
Jackfruit allergy can be added to the list of birchpollen-related food allergies. Increased consumption of this fruit will result in a rise in allergic reactions.
Department Allergology/Dermatology, University Medical Center Utrecht, Utrecht, The Netherlands.
S T H P
ST
Bolhaar
R
R
Ree
C A F M
CA
Bruijnzeel-Koomen
A C
AC
Knulst
L
L
Zuidmeer
D000328:Adult; D000485:Allergens / Q000276:immunology*; D052179:Antigens, Plant; D031622:Artocarpus / Q000276:immunology*; D029662:Betula / Q000276:immunology; D003429:Cross Reactions / Q000276:immunology; D004311:Double-Blind Method; D005260:Female; D005512:Food Hypersensitivity / Q000150:complications / Q000175:diagnosis* / Q000276:immunology; D006801:Humans; D008297:Male; D027845:Malus / Q000276:immunology; D010940:Plant Proteins / Q000276:immunology*; D011058:Pollen / Q000276:immunology*; D006255:Rhinitis, Allergic, Seasonal / Q000150:complications / Q000276:immunology
D000485:Allergens; D052179:Antigens, Plant; D010940:Plant Proteins; C061312:Bet v 1 allergen, Betula