A hyposensitization could help permanently against the allergic reactions

Not only effective against hayfever: A hyposensitization could also help with peanut allergies. A long-term study with allergic children shows that the use of orally administered immunotherapy can successfully suppress the allergy in many patients - permanently. Thus, a large part of the children were still allergy-free four years after the end of treatment. If the results are confirmed in further investigations, the annoying food allergy might be curable in the future.

Allergic to peanuts? Hyposensitization might solve the problem. © Andrey Volodov/ freeimages

Between one and three percent of all children in Western Europe and the US are now allergic to peanuts - twice as many as ten years ago. Why allergies such as these increase, is so far unclear. Nutrition-induced changes in the intestinal flora, the influence of antibiotics and environmental factors such as fine dust or plasticizer are discussed.

Getting used to allergens

While it is difficult to avoid allergens such as pollen and house dust mites, the contact with allergenic foodstuffs can be avoided relatively easily. Among other reasons, the hyposensitization of such allergies has not previously been a routine treatment and has not been studied in research for a long time.

In the meantime, however, the evidence suggests that the method could be as promising for food allergies as for the treatment of hayfever and co. Thus studies show that the immune system can be accustomed to allergens contained in peanuts. In this way, the contact with the nuts can not only prevent an allergy, but can also help in the case of an already developed allergy. It was unclear, however, whether this effect would have a long-term effect.

Immunotherapy in the test

This is exactly what scientists at Mimi Tang from the University of Melbourne in Australia have investigated. For their study, they administered oral immunotherapy for peanut allergens to 31 children with peanut allergy over a period of 18 months. In addition, subjects between one and ten years old were given so-called probiotics. These lactic acid bacteria are intended to support the natural intestinal flora and promote the development of tolerance. For comparison, 31 other allergic children received only a placebo.

To check the success of the therapy, the researchers continued to accompany the participating children for four years. During this time, the consumption of peanuts as well as possible unwanted reactions were documented by means of questionnaires. In addition, the team reviewed the therapy success by means of skin prick testing and the determination of specific antibodies. In some of the subjects, the researchers also conducted an oral provocation test, which had previously been completely without peanuts for eight weeks.

Long-term success

The result: As soon as a few weeks after the therapy, a success became apparent. In contrast to children who had swallowed only the placebo, most of the other patients succeeded in suppressing allergic reactions. But would this effect be permanent? In the long-term evaluation after four years, which could still be carried out with 24 children from both groups, 16 children from the therapy group had apparently remained allergy-free (67%). In the placebo group, however, the allergy had disappeared only in one child.

In the provocation test, a similar picture emerged: Seven of twelve volunteers who had been hyposensitized did not show any reaction in the sudden contact with the peanut allergens. In the control group, only one out of fifteen children did not respond.

Important progress

Despite the comparatively small number of patients and further limitations of the study, experts point out the results as promising:

They point out for the first time that the specific oral immunotherapy in combination with probiotics can effectively suppress allergic reactions also in the long term after the end of the therapy, according to the allergy information service.

This is an important step forward with regard to the goal of producing an immunological tolerance for food allergies.

The Lancet Child & Adolescent Health, 2017; doi: 10.1016 / S2352-4642 (17) 30041-X