The new approach of Molecular Allergology takes the diagnostics one step further by quantifying the allergen specific IgE antibodies to single, pure allergen molecules. The enhanced precision thereby obtained strengthens the clinical utility of IgE testing.
Allergen components – the basis for improved diagnosis
From an allergen source, single allergen components can be produced. Sensitization to these components is then measured individually in separate tests, helping to pinpoint, on an exact molecular level, which component the patient is sensitized to.
This information provides the basis for a refined diagnosis of the allergy. In Molecular Allergology, extract-based testing is used together with componentspecific analyses. The extract gives the overall answer if the patient is sensitized to the particular allergen source, while the components add vital information about risk, specificity and cross-reactivity.
What can allergen components tell us?
Allergen components are proteins and based on structural similarity these are grouped into different protein families. Depending on the properties of these proteins, sensitization to the components leads to different consequences for the patient.
Specific components – unique clues in revealing sources of allergy
Each allergen source typically contains both specific and cross-reactive allergen components. Specific allergen components are more or less unique for their source, found only in a limited number of closely related species. Each allergen source may contain one or a few specific allergen components. Sensitization to any of these indicates a genuine sensitization, meaning that the corresponding allergen source is the primary cause of the clinical symptoms.
Identify cross-reactive components – improve your diagnosis
Cross-reactive allergen components are more widely distributed and may be shared between a very wide range of allergen sources. Due to their high degree of structural similarity, they may cause IgE antibody cross-reactivity.
Cross-reactivity can be exemplifi ed by birch pollen-related food allergy, a syndrome affecting many birch pollen-allergic patients. The underlying molecular reason for this cross-reactivity is that most birch pollen-allergic patients have specifi c IgE antibodies to the component Bet v 1. Bet v 1 has structural similarity to related proteins in many foods, for instance soy and peanut. Thus, the patient’s IgE antibodies to birch Bet v 1 cross-react with these related proteins in soy or peanut.
Protein stability and amount
Food allergen components display different stability to heat and digestion, and their content in the allergen source varies. Both stability and amount are refl ected by the protein family to which the component belongs. Therefore, by knowing the sensitization profi le of the patient and to which family the identifi ed components belong, it is possible to assess the risk associated with the sensitizations.