How Well Do Defined Approaches Predict the Human Skin Sensitisation Potential of Previously Untested Chemicals?
The in vitro prediction of human skin sensitisation took a significant step forward with the publication of the OECD’s Health Effects Guideline 497 on Defined Approaches for Skin Sensitisation in 2021.1
Prior to that, in vitro data was used as a substitute to in vivo methods and validation efforts notoriously presented comparison figures on sensitivity and specificity between the new in vitro method and the existing in vivo method. Publication of the skin sensitisation AOP2 solidified the relationship between molecular perturbations, pathway biology and the resultant adverse human outcome(s) when exposed to chemical substances. Since then, test methods for three of the four key events have been developed and in 2015/2016, Test Guidelines for each were published by OECD.3-5