Assessment of the human Cell Line Activation Test (h-CLAT) for Skin Sensitization_Results of the First Japanese Inter-laboratory Study

Takao Ashikaga1, Hitoshi Sakaguchi2, Kenji Okamoto3, Makoto Mizuno4, Jun Sato5, Takaaki Yamada6, Mayumi Yoshida7, Naoko Ota7, Seiji Hasegawa6, Tatsuji Kodama5, Yuko Okamoto4, Hirofumi Kuwahara3, Nanae Kosaka2, Sakiko Sono1, and Yasuo Ohno8

1Shiseido Co., Ltd., Kanagawa, Japan
2Kao Corporation, Tochigi, Japan
3Kanebo Cosmetics Inc., Kanagawa, Japan
4Kosé Corporation, Tokyo, Japan
5Lion Corporation, Kanagawa, Japan
6Nippon Menard Cosmetic Co., Ltd., Aichi, Japan
7Pola Chemical Industries, Inc., Kanagawa, Japan
8National Institute of Health Sciences, Tokyo, Japan

AATEX 13(1):27-35, 2008

The human Cell Line Activation Test (h-CLAT) is an in vitro skin sensitization test based on the enhancement by sensitizers of CD86 and/or CD54 expression on THP-1 cells. The aim of this study is to confirm the transferability and reproducibility of the h-CLAT protocol. Seven Japanese laboratories participated in this h-CLAT ring study. First, two well-known sensitizers (dinitrochlorobenzene (DNCB) and nickel sulfate (Ni)) and one non-sensitizer (sodium lauryl sulfate (SLS)) were evaluated at each laboratory with the same protocol at the same application dose. All laboratories correctly evaluated the skin sensitization potential of these three chemicals. Next, four sensitizers and one non-sensitizer were tested as a second trial. There were two false-negatives (ethylene diamine and eugenol) in some laboratories. Finally, chemicals tested in the second trial were re-evaluated with doses individually determined by each laboratory as a third trial. The results were almost the same as the results obtained when all the laboratories tested the same application doses. These results suggest that for more precise evaluation of difficult samples (e. g., unstable or water-insoluble chemicals), modifications of the protocol and prediction model are needed. However, the protocol was easily transferred to all laboratories and there were only a few false-negatives among 56 tests (8 chemicals at 7 laboratories).

Key words: Skin sensitization, alternatives, THP-1, reproducibility, h-CLAT


(AATEX: Altern. Animal Test. EXperiment.: Alternatives to Animal Testing and EXperimentation)