[Effect of structure of hapten carrying model substances on contact reaction: DNP conjugates of stereoisomers of alpha-alanine following DNCB sensitization].

By means of epicutaneous tests under standard conditions we studied the cell-mediated contact sensitivity to dinitrophenyl (DNP) conjugates of the stereoisomeric amino acids L-alpha-alanine and D-alpha-alanine, respectively, in patients sensitized with dinitrochlorobenzene (DNCB). There was no difference in the number of positive skin responses with the two enantiomeric compounds DNP-L-alpha-alanine (16/26) and DNP-D-alpha-alanine (17/26). However, as in earlier studies, no patient has shown a positive reaction to the position-isomeric DNP-beta-alanine.