#0072 Trichloroethylene and trichloroethanol induce skin sensitization with focal hepatic necrosis in guinea pigs
Industrial Cleaning Agent Causes Skin Allergies and Liver Damage
The chemical compound trichloroethylene (TCE) is extremely popular as an industrial cleaning solvent, particularly in Asia, due to its low cost and non-flammable nature. However, TCE has been responsible for serious workplace hazards among Chinese workers among whom there have been reports of a hypersensitivity syndrome from being exposed to it. Called TCE hypersensitivity syndrome (TCEHS), the condition is characterized by fever, skin rash, and liver malfunction. While studies have shown TCEHS to be the result of a malfunctioning immune system, it is not clear whether the condition is induced by TCE itself or its metabolites (substances formed during metabolism), trichloroethanol (TCEOH) and trichloroacetic acid (TCA).
In this study, we decided to investigate the allergens (substances that trigger the immune system and cause the skin allergy and liver dysfunction) responsible for TCEHS with the standard guinea pig maximization test (GPMT), which looks at allergic reactions in guinea pigs injected with the substance suspected to be an allergen. Accordingly, we performed the GPMT by injecting healthy guinea pigs with TCE, TCEOH, and TCA and examining their skin and small portions of liver under a microscope. In addition, we looked at the levels of the liver enzymes, alanine aminotransferase (ALT) and gamma-glutamyl transpeptidase (GGTP), in the blood serum as an indicator of liver function.
Based on the skin inflammation score of the guinea pigs, we calculated the sensitization rate (a measure of increased sensitivity) to be 90% for the TCE group, 50% for the TCEOH group, and 0% for the TCA group. Equivalently, we observed a reddening of the skin in the TCE and TCEOH groups but not in the TCA group. Furthermore, we observed increased serum levels of ALT and GGTP in the TCE and TCEOH groups along with signs of focal hepatocyte necrosis (the death of liver cells), indicating liver damage.
Based on these findings, we conclude that both TCE and TCEOH are responsible for the onset of the hypersensitivity syndrome in guinea pigs. Further research on the effects of these chemicals can create a better understanding of their allergenicity, opening doors to prevention and therapeutic strategies for TCEHS.
In the meantime, alternatives to TCE should be explored for industrial cleaning solvents.
Link to the original journal article:
https://onlinelibrary.wiley.com/doi/10.1002/1348-9585.12142
Title of the paper:
Trichloroethylene and trichloroethanol induce skin sensitization with focal hepatic necrosis in guinea pigs
Authors:
Na Zhao, Xiangrong Song, Hisao Naito, Hongling Li, Yongshun Huang, Lili Liu, Fengrong Lu, Tingfeng Cai, Yuki Ito, Michihiro Kamijima, Hanlin Huang, Tamie Nakajima, and Hailan Wang
