The In Vitro Acute Skin Irritation of Chemicals: Optimisation of the EPISKIN Prediction Model within the Framework of the ECVAM Validation Process:

摘要: Abstract In view of the increasing need to identify non-animal tests able predict acute skin irritation chemicals, European Centre for Validation Alternative Methods (ECVAM) focused on evaluation appropriate in vitro models. should be capable discriminating between irritant (I) chemicals (EU risk: R38) and non-irritant (NI) "no classification"). Since major vivo assays rely visual scoring, it is still a challenge correlate clinical signs with biochemical measurements. Being particularly suited test raw materials or wide variety physical properties, models resembling human were involved prevalidation processes. Among many other factors, cytotoxicity known trigger processes, can therefore first common event irritants. A refined protocol (protocol 15min-18hours) EPISKIN model had been proposed inclusion ECVAM formal validation study. further improvement this protocol, mainly based post-treatment incubation period 42 hours 15min-42hours), optimised was applied set 48 chemicals. The sensitivity, specificity accuracy MTT assay-based prediction (PM) 85%, 78.6% 81.3% respectively, low rate false negatives (12%). improved performance confirmed by higher robustness (homogeneity individual responses) better discrimination I NI classes. To improve viability-based PM, release membrane damage marker, adenylate kinase (AK), cytokines IL-1alpha IL-8 also investigated. Combining these endpoints, simple two-tiered strategy (TTS) developed, assay as first, sort-out, stage. This resulted clear increase sensitivity 95%, fall false-positive (to 4.3%), thus demonstrating its usefulness "decision-making" tool. proved, both performances robustness, good candidate process, well potential alternative method assessing irritation.