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Further investigation of the prohapten concept: reactions to benzene derivatives in man
Author(s) -
Basketter D A,
Liden C.
Publication year - 1992
Publication title -
contact dermatitis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 96
eISSN - 1600-0536
pISSN - 0105-1873
DOI - 10.1111/j.1600-0536.1992.tb05216.x
Subject(s) - chemistry , hydroquinone , hapten , benzene , benzoquinone , reactive intermediate , medicinal chemistry , organic chemistry , stereochemistry , antibody , immunology , biology , catalysis
p‐Phenylenediamine (PPDA) is it strong contact sensitizer which is included in the standard patch test tray and winch can also act as an indicator of allergy to related substances by virtue of cross‐reactions In a previous study, the pattern of cross‐reactions between PPDA and related substances was investigated in the guinea pie to evaluate the prohapten concept. The results provided some support for this concept, but also indicated that a number of reactive intermediates might be behaving as haptens. This work has inns been extended to an examination of the prohapten concept in man in PPDA‐allergic subjects. These subjects were tested with 7 substituted benzenes, plus PPDA. Of these, the 1,4‐suhstituted benzenes hydroquinone, Metol. PPDA and p‐aminophenol are all capable theoretically of giving rise to benzoquinone by oxidation (after demethylation in the case of Metol).However as had been the case in the guinea pig, only a limited degree of cross‐reaction was observed. Only one of the subjects allergic to PPDA gave a clearly positive allergic reaction m benzoquinone. The data provided only limned support for the prohapten concept in terms of benzouinone as the ultimate hapten for a range of 1,4‐substituted benzenes. As indicated in the guinea pig, a range of reaction intermediates or indeed other oxidation products may he involved, So, for each molecule, the sensitizing activity and potential to give rise to cross‐reactions may depend on the balance between routes of skin metabolism