Ragweed nAmb a 1 IgE, w230
A new direction has emerged in the diagnosis of allergic reactions: Molecular diagnosis of allergies is a component allergy diagnosis.
The basis of molecular diagnosis of allergies is the identification of sensitization to allergens at the molecular level using natural, highly purified and recombinant allergen molecules, that is, their components, and not extracts. In the late 1980s, when DNA technology began to be introduced, allergen molecules were characterized and cloned, which helped identify antigenic determinants in various allergic diseases. All this played an important role in the emergence of a new type of diagnostics - molecular diagnostics, which, in turn, contributed to the development of more effective treatment for allergies. Determination of antibodies to recombinant allergens makes it possible to identify the leading component in the composition of complex allergens at the level of molecular allergology. This allows you to differentiate true and cross allergies. The use of recombinant allergens represents a new tool in the diagnosis of type I allergic reactions, which allows one to obtain detailed information about the patient’s sensitization, cross-reactivity with other allergens, justify the feasibility and predict the effectiveness of allergen-specific immunotherapy (ASIT).
This direction will change views on the examination and treatment of patients and bring them into line with those in world medicine.
There are 3 main advantages of performing this study:
- Molecular allergy 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 one, several closely related ones, or many different ones.
- Molecular allergy diagnostics will eliminate the need for provocative tests and make it possible to give clearer recommendations regarding eliminating contact with allergens.
- Molecular allergy diagnostics is necessary in the selection of allergen-specific immunotherapy (ASIT); in individuals with polyvalent sensitization, the most accurate way to determine the most important allergen for which ASIT will be performed. It has been shown that the use of molecular diagnostic methods forces a change in ASIT, selected based on the results of skin prick tests.
In order to begin using allergen components and correctly interpret research results, you need to know basic information about allergen components and their clinical use:
Allergen molecules are given a name, first the first three letters of the Latin name of the genus, then the first letter of the species and an Arabic numeral - the allergen number (the number depends on the order of isolation and/or clinical importance).For example: Birch – Bet v 1, Bet v 2, etc.
The composition of an allergenic substance includes not one, but several protein components that can act as allergens: “major” - the main allergens, others “minor” - minor.
Major allergenic components are allergenic molecules to which antibodies are found in more than half - 50% of patients in the population reacting to a given source. They are heat resistant and more immunogenic. Large in size and contained in this allergen in larger quantities.
Minor molecules are smaller in size and less immunogenic allergenic molecules, which are usually contained in smaller quantities 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, and less than 10% are called minor.
The culprits of allergies include grasses and trees. One of the representatives of herbs is ambrosia.
Ambrosia (Latin name Ambrósia) is a weedy herbaceous plant native to North America and now widespread throughout the world. Ambrosia pollen can be spread by the wind hundreds of kilometers from dusting sites and is a common cause of respiratory allergies in the second half of summer - early autumn.Clinical manifestations of allergy to weed pollen are allergic rhinitis, allergic conjunctivitis, bronchial asthma during pollination.Ambrosia pollen is highly allergenic and even in very low concentrations (5-10 pollen grains per cubic meter of air) can cause a reaction in sensitized people. The flowering periods of ragweed and wormwood practically coincide and both plants are cross-reactive. True sensitization and cross-reactivity to the pollen of these plants can be differentiated by testing for recombinant allergens.
Для определения сенсибилизации к амброзии, как сложному аллергену, исследуется главный мажорный аллерген nAmb a 1 IgE.
Определение в крови nAmb a 1 IgE, позволяет диагностировать истинную аллергию к амброзии и дифференцировать перекрестную реактивность с другими травами.
Аллерген Amba 1 – белок из группы пектатлиаз. Несмотря на высокую специфичность аллергена Amba 1, перекрестная реактивность может отмечаться с другими растениями, также содержащими фермент пептатлиазу, среди которых томаты, табак и японская криптомерия. Аллерген Amba 1 обладает схожей структурой с аллергеном пыльцы тимофеевки Phlp 4, чем обуславливается перекрестные аллергические реакции на пыльцу злаковых и сорных трав.