The inter-laboratory validation study of EpiSensA for predicting skin sensitization potential

Area of Science:

• Toxicology
• Dermatology
• In vitro toxicology

Background:

• Skin sensitization is a significant health concern.
• Accurate prediction of chemical skin sensitization is crucial for regulatory assessment and public safety.
• Existing methods may have limitations in testing diverse chemical types and exposure routes.

Purpose of the Study:

• To validate the Epidermal Sensitization Assay (EpiSensA) for predicting skin sensitization potential.
• To assess the transferability of the EpiSensA to new laboratories.
• To determine the within- and between-laboratory reproducibility of the EpiSensA.

Main Methods:

• A formally managed validation study involving three independent laboratories.
• Utilized a reconstructed human epidermis (RhE)-based gene expression assay (EpiSensA).
• Involved two independent stages with coded test chemicals, including sensitizers, non-sensitizers, lipophilic compounds, and pro-/pre-haptens.

Main Results:

• Successful transfer of the EpiSensA to all participating laboratories.
• High within-laboratory reproducibility (WLR) ranging from 86.7% to 93.3%.
• Strong between-laboratory reproducibility (BLR) of 88.9% for 27 test chemicals, with predictive capacity showing 92.6% sensitivity and 82.7% accuracy compared to LLNA.

Conclusions:

• The EpiSensA is easily transferable to new laboratories.
• The assay demonstrates sufficient robustness and reproducibility for assessing chemical skin sensitization potential.
• EpiSensA offers a reliable in vitro method for predicting skin sensitization, accommodating various chemical types and exposure scenarios.