EXPERIMENTAL-STUDY FOR THE DEVELOPMENT OF AN IN-VITRO TEST FOR CONTACT ALLERGENS - 2 - COMPARISON OF THE IN-VITRO SENSITIZATION TEST WITH THE GUINEA-PIG MAXIMIZATION TEST FOR CONTACT ALLERGENS

We have previously reported an in vitro hapten-specific sensitization method using Pam-212 cells (in vitro sensitization test) to identify t he potential effectiveness of contact allergens. In the present study, we conducted comparison studies of 11 allergens and 2 irritants in or der to evaluate the method as an alternative predictive teal. The guin ea pig maximization test (GPMT) was developed based on the lest descri bed by Magnusson and Kligman. Om assay was carried out as follows: we treated Pam-212 cells with 13 test chemical solutions: while T cells a nd macrophages of BALB/c mice were cultured with hapten-conjugated Pam -212 cells for 5 days. After incubation, 10(5) T cells were stimulated with mitomycin-C-treated spleen cells conjugated with chemicals. Thre e days later, the [H-3]methyl thymidine incorporation was counted. The results of the GPMT were in agreement with those reported in previous studies except for benzocaine. In our GPMT experiments, benzocaine wa s negative, but it had been classified as a moderate sensitizer in pre vious studies. Our assay detected extreme, strong and moderate sensiti zers as previously classified by the GPMT. They could be summarized as follows: three of five chemicals classified as moderate sensitizers. and 100% of strong or extreme sensitizers were detected by both the GP MT and the in vitro sensitization test, No irritants showed a positive reaction in our assay, These results support the view that the sensit ivity of our in vitro test mat-be equivalent to that of the GPMT and m ay be useful as a rapid and objective allergen screening test.