Route of contact sensitization and in vitro lymphocyte transformation.

A guinea pig skin extract conjugate with dinitrofluorobenzene elicited significant in vitro transformation of cultured lymphnode lymphocytes from 19 of 27 guinea pigs sensitized by footpad injection of dinitrochlorobenzene in Freund's complete adjuvant, as compared to only 1 of 26 guinea pigs topically sensitized to dinitrochlorobenzene. Topically sensitized guinea pigs appear to be more appropriate models for contact allergy in man than guinea pigs sensitized by other methods. Other sensitization procedures are likely to produce more heterogeneous forms of sensitization, with features of contact allergy, tuberculin-type allergy, antibody-mediated hypersensitivity and cutaneous basophile hypersensitivity.