Allergic reaction to birch pollen explored

Researchers are tracking the cause of allergies through birch pollen

06/05/2014

When the first birch pollen fly through the air in the spring, a stressful time begins for allergy sufferers. Frequent sneezing, itching and watery eyes and a runny nose make it difficult for hay fever sufferers. Why but especially birch pollen provide allergic reactions, was previously only partially known. Guilt is a particular protein. Why is this highly allergenic, found recently Austrian scientists.

Birch pollen protein becomes allergen due to lack of iron
The so-called „Bet v 1“-Protein is one of the best-known allergens. It comes from birch pollen (Betula verrucosa) and was first artificially produced in the laboratory around 25 years ago. Since then, it has been used worldwide as an allergen model in research. „Bet v 1“ is the major allergen among birch pollen proteins. 95 percent of people with birch pollen allergy respond with the formation of pathogenic antibodies (IgE immunoglobulins).

The researchers led by Franziska Roth-Walter from the Messerli Research Institute, a joint institution of the Vetmeduni Vienna, the University of Vienna and the MedUni Vienna, wanted to find out why an actually harmless protein can cause allergies. In the context of their investigations, they encountered a high degree of structural similarity „Bet v 1“ and the human protein, Lipocalin 2, which is found mainly in the lungs. Both proteins have so-called molecular pockets that serve to bind iron. If no iron is tied in the pockets, will „Bet v 1“ to the allergen. Then it manipulates T-helper2 cells (Th2 cells). In people with allergies, these Th2 cells are predominant, unlike Th1 cells. Th2 cells play an essential role in allergic reactions and the control of parasites. In contrast, Th1 cells fight off bacterial and viral infections.

„Typical of allergies is a disturbed balance between Th1 and Th2 immune response“, reports the head of the Department of Comparative Medicine at the Messerli Research Institute, Erika Jensen-Jarolim. „Work in progress indicates that we can directly apply the birch pollen allergen principle to other allergens of similar molecular structure. Thus, for the first time, we begin to understand why allergies to pollen, food and fungal spores actually originate.“

Mechanisms of iron loading of birch pollen proteins are still unknown
It is still unclear which mechanisms lead to „Bet v 1“ not loaded or only reduced with iron. „The iron loading of the birch protein could be related to increased environmental conditions to which the plants are exposed“, explains the scientist. „There may even be a direct link between environmental pollution and rising allergy numbers. In the future it will make sense to have allergenic molecules of the type „Bet v 1“ specifically loaded with iron when they are used for immunotherapy in allergy sufferers. This could significantly shorten this therapy, which lasts two to four years today, and increase its efficiency.“

Combat birch pollen allergy with naturopathy
Until appropriate therapy is available to those affected, there is usually only the lengthy hyposensitization, in which the patient the allergen is slowly administered in low and later increasing dose in order to achieve an immunological habituation. In naturopathy, the self-blood therapy, Bach flower therapy, therapeutic hypnosis and intestinal rehabilitation can also be used successfully. These therapies have the advantage of provoking little or no unwanted side effects.