Birch pollen and food allergy: Antibodies in battle to bind
(Vienna, 28 Feb. 2011) The frequent joint occurrence of allergies against birch pollen and plant nutrients was the reason for a study at MedUni Vienna. The investigations showed the direct connection and identified specific antibodies for protection against these allergic reactions.
The scientists in the laboratory of biotechnologist Barbara Bohle, Professor of Cellular Allergology at MedUni Vienna, are dedicated to studying the immune response to allergens. Here a recently published study focused on patients who are allergic to birch pollen. Dr. Marija Geroldinger-Simic discovered that 70% of the 225 allergic study participants showed symptoms of a food allergy at the same time, with more than 80% of these cases being chronic. The main causes of birch pollen-related food allergy were shown to be apples and hazelnuts, which usually led to various oral symptoms (e.g. a tickle in the throat) and can also often be the cause of hay fever.
A key role in this research work is played by allergen-specific antibodies of immunoglobulin class G4 (IgG4), an immunoglobulin of the humoral immune system which defends against pathogenic agents which have penetrated into the body fluids blood or lymph. IgG4 antibodies compete with the allergen-specific IgE (immunoglobulin class E) antibodies - which are known to trigger allergies - to bind to the allergen and are therefore seen as "blocking" antibodies.
The team discovered that in patients with food tolerance there is a statistically verifiable higher ratio of allergen-specific IgG4 to IgE antibodies. It also showed that IgG4 prevents IgE binding to food allergens so there is therefore no wrong immune response. A connection can therefore be made between the presence of allergen-specific IgG4 antibodies and food tolerance. It also means, however, that IgG antibodies are not suitable as markers for a food allergy triggered by birch pollen.
Publication in „The Journal of Allergy and Clinical Immunology“:
Birch pollen-related food allergy: Clinical aspects and the role of allergen-specific IgE and IgG(4) antibodies
Geroldinger-Simic M, Zelniker T, Aberer W, Ebner C, Egger C, Greiderer A, Prem Md N, Lidholm J, Ballmer-Weber BK, Vieths S, Bohle B
Journal of Allergy and Clinical Immunology (JACI) (Jan 2011)