Applicability of the proposed GHS subcategorization criterion for LLNA:BrdU‐ELISA (OECD TG442B) to the CBA/J strain mouse

• Published in: Journal of applied toxicology 2020-10, Vol.40 (10), p.1435-1439
• Main Authors: Kobayashi, Toshio, Maeda, Yosuke, Kondo, Haruka, Takeyoshi, Masahiro
• Format: Article
• Language: English
• Subjects: Bromodeoxyuridine; CBA/J mouse; Chemicals; Classification; Communications systems; Correlation analysis; Criteria; Enzyme-linked immunosorbent assay; GHS; Labeling; LLNA:BrdU‐ELISA; Local lymph node assay; Lymph nodes; OECD TG442B; Performance standards; skin sensitization; subcategorization
• ISSN: 0260-437X; 1099-1263
• DOI: 10.1002/jat.3996

The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is a hazard classification and communication system for providing information on the safe handling of chemicals worldwide. In this study, we evaluated the applicability of the newly proposed GHS subcategorization criterion for murine local lymph node assay:2‐bromodeoxyuridine enzyme‐linked immunosorbent assay (LLNA:BrdU‐ELISA), Category 1A:EC1.6 ≤6%, Category 1B:EC1.6 >6%, to data derived from LLNA:BrdU‐ELISA performed in the CBA/J strain mouse. Fifteen chemicals categorized in GHS hazard Category 1 sensitizers listed in the LLNA performance standard were tested by LLNA:BrdU‐ELISA in the CBA/J strain mouse and were classified according to the new criterion. The results revealed that all of the GHS 1A or 1B category chemicals classified according to the EC3 values derived from radioisotopic LLNA (LLNA‐RI) could be correctly assigned into the respective 1A and 1B categories using the newly proposed GHS subclassification criterion. In addition, analysis of the correlation between the reported EC3 values and EC1.6 values derived from the LLNA:BrdU‐ELISA performed in the CBA/J strain mouse confirmed the existence of a strong correlation (r = 0.9076, P < .0001). These findings suggest that the newly proposed GHS subcategorization criterion for LLNA:BrdU‐ELISA is potentially applicable for practical use in GHS subcategorization. We evaluated the applicability of the newly proposed GHS subcategorization criterion for LLNA:BrdU‐ELISA to CBA/J strain mouse. Fifteen skin sensitizers were tested and classified according to the proposed criterion. Consequently, all of the GHS 1A or 1B category chemicals decided by the EC3 values of radioisotopic LLNA were correctly assigned into each 1A or1B category by using the newly proposed GHS subclassification criterion. Therefore, the LLNA:BrdU‐ELISA is practically applicable for the GHS subcategorization.