Guinea pig sensitization assays: an experimental comparison of three methods

Abstract

Purpose: Guinea pig sensitization assays provide a critical tool in toxicological testing. Here, we investigate the relative sensitivities of the Guinea Pig Maximization Test (GPMT), the Open Epicutaneous Test (OET), and the Buehler test on seven common compounds.

Methods: Seven compounds (formalin, nickel sulfate, 2-benzothiazolethiol, neomycin sulfate, potassium dichromate, ethylenediamine, dihydrochloride, and cinnamyl alcohol) were investigated on 15 guinea pigs per assay. Differences between each assay were investigated individually for each compound in question, and cumulative comparisons were also performed.

Results: Cumulatively, differences in rates of sensitization between the GPMT and OET did not reach statistical significance; however, both tests produced higher sensitization rates than the Buehler test (1% significance level). Comparisons for individual compounds are outlined within the main text.

Conclusions: Our results indicate a possible role for the OET in the testing of weakly allergenic compounds. Similarly, the Buehler test may hold greatest utility in the examination of strongly allergenic compounds, where high sensitivity is not necessary and limited exposure to subjects is desired. These findings may help guide experimental protocols and considerations.