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). Conclusion 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.
Symptoms of kiwifruit allergy vary from mild oral symptoms to severe systemic reactions.2 Studies investigating the allergenicity of different kiwifruit cultivars are scarce and mostly limited to in ...vitro evaluation, focusing on the common green and gold kiwifruits (Hayward and Hort16A, the latter marketed as Zespri Gold).3,4 The aim of this study was to determine the differences in allergenicity of 6 different kiwifruit cultivars in vivo by prick-to-prick-test (PPT) and food challenge (FC) and in vitro by IgE ELISA. The finding that Summer 3373 and the gold Hort16A kiwifruit may be less allergenic than the common green kiwifruit Hayward in some of the patients with kiwifruit allergy may offer these patients a safe way to reintroduce kiwifruit into their diets.\n33 ND K2 NL 40 F OAS, CU G, B 0 ND K3 NL 41 F OAS, D, TT G, B, MU 0.83 OAS, H, TT, CO, ANG, DI, P, PA K4 NL 41 F OAS G, B 0 ND K5 NL 26 F OAS G, B 0 OAS, HE, R, I, CO, CR K6 NL 33 M OAS, TT G, B 0.50 ND K7 NL 27 F OAS G, B, MU 0.50 OAS, E K8 NL 29 F OAS, N G, B, MU 0 ND K9 NL 26 F OAS, TT G, B 0 OAS K10 NL 24 F OAS B, MU 0 ND K11 NL 25 F OAS, R, TT G 0.54 ND K12 NL 29 M OAS, TT G, B 1.38 ND K13 NL 43 F OAS G, B, MU 0 OAS, ANG K14 NL 50 M OAS, TT, DP B 0 ND K15 NL 26 F OAS, CR, DI B 0.33 ND K16 NL 29 F OAS, U, TT, CO G, B 0 ND K17 NL 33 F OAS, TT, DP G, B, MU 0 ND K18 NL 22 F OAS, U, I, A, TT G, B, MU 0.83 OAS, BL K19 NL 22 F OAS G, B, MU 0 ND K20 NL 17 F CU G, B 0.25 ND K21 NL 21 F OAS, CU G, B 0 ND K22 NL 29 F OAS, TT ND 0 OAS, TT, CO, DP, D, HE K23 NL 24 F OAS ND 0 OAS, N K24 NL 22 F OAS ND 0 OAS, TT K25 NL 51 F OAS ND 0 No symptoms K26 NL 53 F OAS ND 0 No symptoms KW1 CH 35 M OAS G, B, MU 0 OAS KW2 CH 22 F OAS G, B 0 OAS KW3 CH 20 F OAS, CU G, B, MU 0.4 OAS, ANG KW4 CH 25 F OAS G, B, MU 0 OAS KW5 CH 28 M OAS, D, L G, B, MU 0.27 OAS, DY KW6 CH 55 F OAS, DY G, B 0 OAS, DY KW7 CH 18 F OAS G, B, MU 0 OAS, ANG KW8 CH 45 M OAS, ANG G, B, MU 0 OAS KW9 CH 33 F OAS G, B, MU 0 OAS KW10 CH 33 M OAS G, B, MU 0.47 OAS, SS KW11 CH 24 F OAS, BL G, B, MU 0 OAS low * Clinical characteristics of patients with kiwifruit allergy A, Asthma; ANG, angioedema; B, birch; BL, blisters; CH, Switzerland; CO, conjunctivitis; CR, abdominal cramps; CU, contact urticaria; D, dysphonia; DI, diarrhea; DP, dyspnea; DY, dysphagia; E, erythema; F, female; G, grass; H, hoarseness; HE, headache; I, itching; ID, patients' characteristics; L, laryngeal edema; M, male; MU, mugwort; N, nausea; ND, not done; NL, The Netherlands; OAS, oral allergy symptoms; P, perspiring; PA, pale; R, rhinitis; SS, strong salivation; TT, tightness of throat; U, urticaria.
