Non-IgE-mediated allergies in the horse - case report of a Type-IV-Allergyto cotton wool

The authors present the case of a cell-mediated Type IV-Allergy to cotton w ool in a horse, which was clinically suspected by veterinarians and confirm ed by an in- vitro-lymphocyte-transformation-test (LTT). They explain the l aboratory diagnostic procedure of the LTT, which is a reliable method for d etection of allergen-specific memory T-lymphocytes in the peripheral blood. This method, which was recently only used in human laboratory medicine, an alyzes the uptake of tritium-labeled Thymidine in newly synthesized DNA of activated proliferating lymphocytes. Furthermore, the mechanisms and the po ssible clinical relevance of lymphocyte-induced allergic diseases (Type IV) as well as antibody-induced immediate hypersensitivities (Type I) in horse s are reviewed and discussed.