Kiwi allergyL27.-, L27.2, L23.6, T78.0, T78.3

Kiwi is now considered one of the main causes of fruit allergies. The kiwi fruit (preferably Actinidia deliciosa = green kiwi) has acquired this allergological significance over a period of 3 decades (introduced in the 80s of the last century). Mild local(oral allergy syndrome, contact urticaria) but also anaphylactic reactions can occur. The golden kiwi (Actinidia chinensis), which was introduced in Europe only later, generally causes fewer allergic symptoms. The cysteine protease actinidine is an important marker allergen for primary kiwi sensitization. This proteolytic enzyme actinidine is used in the food industry as a meat softener.

Currently 13 kiwi allergens are officially recognised (see http://allergen.org)

Currently 13 allergens are registered in the official database IUIS of the allergen nomenclature (Act d 1- Act d 13). A component-specific diagnosis allows the differentiation between pollen-associated secondary and primary sensitization (danger of anaphaectic reactions).

• Act d 1 the main allergen Act d 1, is a highly active protease (Actinidin: Papain-like cysteine protease s.a. Cysteine) is enriched in ripe fruits. It is a marker protein for primary kiwi sensitization, as has been repeatedly proven. Sensitized patients are at risk for anaphylactic reactions. Cysteine proteases are also used as softeners in the meat industry.
• Act d 2 is an important kiwi allergen a member of the thaumatin-like proteins.
• Act d 5 Kiwellin (major allergen; marker allergen for primary kiwi sensitisation)
• Act d 8, a Pr-10 protein(Bet v 1 homologous protein) is responsible for cross-reactivity with pollen (birch pollen-associated food allergy), like Act d 9, which belongs to the profilin family.
• Act d 9 Profilin
• Act d 10 is a lipid transfer protein and shows low cross reactivity with peach Pru p3.
• Act d 11 belongs to the (sub)family of"Major Latex Proteins/Ripening Related Proteins".

With regard to the type of sensitization, 2 ways are described (Ballmer-Weber 2015):

• In the case of monosensitization, the allergic symptoms are only triggered by the consumption of the kiwi fruit.
• In case of a pre-existing sensitization against birch pollen, grass pollen or latex, cross-reactive sensitization against kiwi may occur (see also latex fruit syndrome).

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3. Chruszcz M et al. (2013) Structural and bioinformatic analysis of the kiwifruit allergen Act d 11,
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