Cashew nut rAna o 3 IgE, f443

Ana o 3 is a water-soluble 2S albumin, a reserve protein of cashew nut seeds (Anacardium occidentale).

Ana o 3 sensitization causes severe systemic reactions and anaphylaxis in people with cashew allergy. This protein is resistant to gastric and intestinal digestion by pepsin and trypsin. Ana o 3 immunoreactivity was reduced by heat treatment methods such as blanching, autoclaving, or frying (10 min), but it could be increased by high temperature treatment (170 ℃ for 20 min).

Allergy component diagnostics is based on the detection of sensitization to allergens at the molecular level using natural highly purified and recombinant allergen molecules, i.e. their individual allergy components.

There are 3 main advantages of doing this analysis:

Allergocomponent diagnostics, makes it possible to differentiate true sensitization from sensitization due to cross-reactivity. This data will help determine the sources of allergies: one single allergy, several closely related ones, or many different ones.
Molecular allergy diagnostics will eliminate the need for provocative tests and allow you to give clearer recommendations regarding the elimination of contact with allergens.
Molecular allergodiagnostics is necessary in the selection of ASIT, in persons with polyvalent (multiple) sensitization, the most accurate way to determine the most important allergen for which therapy will be performed.

The allergenic substance contains not one but several protein components that can act as allergens:
Major allergen components are the main allergenic molecules, antibodies to which are found in more than half – 50% of patients in the population responding to this source. They are resistant to heat and more immunogenic. They are large and are contained in this allergen in larger quantities.

Minor are secondary smaller in size and less immunogenic allergenic molecules that are usually contained in smaller amounts in the allergen but are present in many different allergens, sometimes not closely related, providing cross-allergy. That is, allergens with a prevalence of more than 50% are called major allergens and less than 10% are called minor allergens.

In addition, Ana o 3 can serve as a marker of primary sensitization to cashew nuts. Monosensitization to Ana o 3 without sensitization to other food allergens may be the strongest predictor of severe anaphylaxis.

Extensive cross-reactivity has been reported between cashew nuts and pistachios due to cross-reactivity between their 2S albumins, i.e. Ana o 3 and Pis v 1 (pistachios). In addition, Ana o 3 also cross-reacts with Jug r 1 (walnut) and to some extent with Cor a 14 (hazelnut).

Analysis method: ImmunoCAP method (Immunofluorescence in the solid phase)

Units of measurement: kU/l

Biomaterial for analysis: venous blood