Component-resolved diagnosis of kiwifruit allergy with purified natural and recombinant kiwifruit allergens.
BACKGROUND
Kiwifruit is one of the most common causes of food allergic reactions. Component-resolved diagnostics may enable significantly improved detection of sensitization to kiwifruit.


OBJECTIVE
To evaluate the use of individual allergens for component-resolved in vitro diagnosis of kiwifruit allergy.


METHODS
Thirty patients with a positive double-blind placebo-controlled food challenge to kiwifruit, 10 atopic subjects with negative open provocation to kiwifruit, and 5 nonatopic subjects were enrolled in the study. Specific IgE to 7 individual allergens (nAct d 1-5 and rAct d 8-9) and allergen extracts was measured by ImmunoCAP.


RESULTS
The diagnostic sensitivities of the commercial extract and of the sum of single allergens were 17% and 77%, respectively, whereas diagnostic specificities were 100% and 30%. A combination of the kiwi allergens Act d 1, Act d 2, Act d 4, and Act d 5 gave a diagnostic sensitivity of 40%, whereas diagnostic specificity remained high (90%). Exclusion of the Bet v 1 homolog recombinant (r) Act d 8 and profilin rAct d 9 from this allergen panel reduced sensitivity to 50% but increased specificity to 40%. Kiwifruit-monosensitized patients reacted more frequently (P < .001) with Act d 1 than polysensitized patients, whereas the latter group reacted more frequently with rAct d 8 (P = .004).


CONCLUSIONS
Use of single kiwifruit allergen ImmunoCAP increases the quantitative test performance and diagnostic sensitivity compared with the commercial extract. Bet v 1 homolog and profilin are important allergens in pollen-related kiwifruit allergy, whereas actinidin is important in monoallergy to kiwifruit, in which symptoms are often more severe.
Bublin
Merima
M
Department of Pathophysiology, Medical University of Vienna, Vienna, Austria.
Pfister
Marina
M
Radauer
Christian
C
Oberhuber
Christina
C
Bulley
Sean
S
Dewitt
Asa Marknell
AM
Lidholm
Jonas
J
Reese
Gerald
G
Vieths
Stefan
S
Breiteneder
Heimo
H
Hoffmann-Sommergruber
Karin
K
Ballmer-Weber
Barbara K
BK
D029042:Actinidia / Q000009:adverse effects / Q000276:immunology*; D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000009:adverse effects / Q000276:immunology*; D004311:Double-Blind Method; D005260:Female; D005512:Food Hypersensitivity / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D008875:Middle Aged; D010936:Plant Extracts / Q000009:adverse effects / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D012680:Sensitivity and Specificity; D012882:Skin Tests; D055815:Young Adult
D000485:Allergens; D010936:Plant Extracts; D011994:Recombinant Proteins; D007073:Immunoglobulin E