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The basophil degranulation test (BDT) complements the type I allergy testing

For some issues, functional type I allergy tests have proved to be a useful complement to the detection of IgE antibodies In the basophil degranulation test (BDT), basophil granulocytes from the patient's blood are concentrated and stimulated in the laboratory with allergen extracts or native food (which is sent in also).

Image: The BDT is a laboratory test that can verify or rule out an immediate-type sensitisation in vitro (that is, with no danger to the patient).

The BDT is a complement to the IgE testing in the case of the following issues:

  1. Testing for foods that are not available in the IgE automated analyses or for the prick test.
  2. Investigation of allergies with complex food mixtures.
  3. In individual cases, due to high sensitivity with negative specific IgE and continuing clinical suspicion of a type I sensitisation.
  4. In the case of non-IgE-mediated pseudoallergies e.g. to food additives.

Image: The patient had reacted with anaphylaxis after ingesting the diet powder together with a yoghurt drink. The testing on native samples of the two suspected foods showed that she is sensitised to an ingredient in the diet powder. For legal reasons, the name of the manufacturer has been blacked out.  

Material

Detection of specific IgE (CAP testing):
10 ml whole blood is sufficient for a minimum of 20 allergens.

Food IgE blot (20 allergens): 10 ml whole blood

Basophil degranulation test (BDT): 2 ml EDTA blood, or alternatively, heparin blood per allergen


Literature

  • Agata H,. et al. Evaluation of lymphocyte proliferative responses to food antigens with regard to age and food-specific IgE antibodies in food-sensitive atopic dermatitis. J Investig Allergol Clin Immunol. 1993;3:174.
  • Kondo N. et al. Lymphocyte responses to food antigens in patients with atopic dermatitis who are sensitive to foods. J Allergy Clin Immunol. 1990;86:253.
  • Reekers R. et al. The role of circulating food antigenspecific lymphocytes in food allergic children with atopic dermatitis. Br J Dermatol. 1996;135:935.
  • Tainio VM, Savilahti E. Value of immunologic tests in cow milk allergy. Allergy. 1990;45(3):189.
  • Werfel T et al. Milk-responsive atopic dermatitis is associated with a casein-specific lymphocyte response in adolescent and adult patients. J Allergy Clin Immunol. 1997;99:124.