Studies on contact sensitivity to DNCB in guinea pigs by the macrophage migration test.

Guinea pigs contact-sensitized to 2,4-dinitrochlorobenzene (DNCB) by foot-pad injections or by topical applications of the hapten were studied by the direct macrophage migration test using DNP-guinea pig albumin (DNP-Alb) and DNP-guinea pig skin extract (DNP-SE) as antigens. Specific inhibition of macrophage migration in the presence of either antigen was found in a significant number of animals exhibiting contact sensitivity to DNCB. However, a wide variation in migration indices was observed in both groups of sensitized animals, with some animals showing a significant enhancement of macrophage migration.