Currant allergy and the Rosaceae-grass pollen allergy syndrome: a case report.
BACKGROUND
Despite the increasing use of currants in culinary recipes, currant allergy has rarely been reported.


OBJECTIVE
To study a case of currant allergy and to explore cross-reactivity between grass pollen and Rosaceae family fruit allergens.


METHODS
Skin prick tests to pollen and skin prick-to-prick tests with currants and peach were performed. Specific IgE levels were determined using the CAP method. We prepared a protein extract of 0.1 mg/mL in phosphate-buffered saline using red currant in the presence of protease inhibitors. Immunoblot inhibition studies were performed to explore cross-reactivity between grass pollen and currant allergens.


RESULTS
Skin prick test results were positive to Dactylis, arizonic, and olive pollens. Results of skin prick-to-prick tests with fresh red and black currants were negative and positive, respectively, to peach. The specific IgE level was 5.7 KU/L to red currant and 2.92 KU/L to peach (CAP). Western blot analysis with red currant extract revealed specific IgE protein bands of 37 and 26 kDa. Preincubation of sera with extracts from red currant and peach inhibited both IgE bands, and preincubation with Dactylis pollen inhibited the 37-kDa band only.


CONCLUSIONS
We report a case of allergy to grass pollen with an oral allergy syndrome involving several fruits from 2 different families of the Rosidae subclass confirmed by in vitro tests. Inhibition studies demonstrated cross-reactivity between different fruits (currant and raspberry) from the Rosidae subclass and were incomplete with grass pollen allergens.
Pérez-Ezquerra
Patricia Rojas
PR
Allergy Department, Gregorio Marañón Hospital, Madrid, Spain. projasperezezquerra@hotmail.com
de la Gaspar
Maria Vazquez Torre
MV
de Fernández
Manuel Barrio
MB
Flores
Vanesa Tovar
VT
Alvarez-Santullano
Ana Villanueva
AV
de Ocáriz
Maria Luisa Baeza Ochoa
ML
D003429:Cross Reactions; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology*; D007073:Immunoglobulin E / Q000097:blood; D008875:Middle Aged; D011058:Pollen / Q000276:immunology*; D031965:Ribes / Q000276:immunology*; D027824:Rosaceae / Q000276:immunology*; D012882:Skin Tests; D013577:Syndrome
D007073:Immunoglobulin E