Letter to the editor: Serum cytotoxic T lymphocyte-associated antigen 4 in Hymenoptera venom allergy and its modulation by specific immunotherapy

Allergy, in a broad sense, encompasses all the clinical manifestations of the atopic status that is characterized by an abnormal IgE response to ubiquitous substances, including environmental and food proteins. It is recognized that, when the contact with the offending allergen is occasional and isolated (eg, Hymenoptera venom allergy [HVA]), a pure IgE- mediated reaction takes place, with a sudden release of mast cellderived mediators. In these cases specific immunotherapy (SIT), which affects the response to allergens, is highly effective. On the contrary, when the exposure to the allergen is prolonged, a chronic inflammation also occurs. T lymphocytes are responsible for the deviation toward the atopic status, and this deviation is essentially driven by regulatory T cells,1 so that an impairment in the function of regulatory T cells can lead to both autoimmunity and allergy.