T Cell Responses to Paraphenylenediamine and to Its Metabolites Mono- and Diacetyl-Paraphenylenediamine

Allergy in the 21st Century: New Answers to Old Questions. 23rd Symposium of the Collegium Internationale Allergologicum. May 18-23, 2000, Hakone, Japan. Editors: Takeru Ishikawa, Kumamoto; Terumasa Miyamoto, Tokyo; Hirokazu Okudaira, Tokyo; Hisao Tomioka, Chiba; Rudolf Valenta, Vienna; Dietrich Kraft, Vienna Paraphenylenediamine (PPD) is one of the most common allergens among patients with allergic contact dermatitis. It is used as an antioxidant, an ingredient of hair dyes, intermediate of dyestuff, and is a chemical for photographic processing. Humans are exposed to PPD by skin contact [1]. In general, small molecular compounds need metabolic activation to become immunogenic. Therefore, the balance between activation and/or detoxification processes is critical for immunogenic potentials of such compounds. PPD may be oxidized to Bandrowski's base [