Abstract 4646: Occupational exposure to trichloroethylene and plasma concentrations of IL6, IL10, and TNF alpha

Abstract

Abstract Trichloroethylene (TCE) is a chlorinated solvent primarily used as a vapor degreaser in many industries. TCE is currently classified by IARC as probably carcinogenic to humans (Group 2A), and has been associated with non-Hodgkin lymphoma (NHL) in some epidemiological studies, although the findings have been inconsistent. To explore the biologic plausibility that TCE may be a lymphomagen, we conducted a cross-sectional study of workers exposed to TCE in Guangzhou, China and tested if plasma levels of the cytokines IL6, IL10, and TNF-alpha, which play a critical role in regulating various components of the immune system, were altered in exposed workers. We enrolled 80 workers from factories where TCE was used as well as 96 unexposed controls matched by sex and age from food and clothes manufacturing factories. Personal exposure measurements were taken over a three-week period, two to three per subject, in the exposed subjects for a full work shift using a 3M badge, as well as for a subgroup of the control workers. Blood samples were collected from each subject, and plasma concentrations of IL6, IL10, and TNF-alpha were measured by ELISA. Linear regression using the natural logarithm of each endpoint and adjusting for potential confounders was used to test for differences in marker concentrations between controls and exposed workers. The mean TCE exposure level in exposed subjects was 23.9 ppm (95% C.I. 14.2-33.6 ppm). Compared to unexposed workers, the plasma concentration of IL10 in workers exposed to TCE was decreased by more than 50% compared to controls (p=0.003), while there was no difference in levels of IL6 or TNF-alpha in TCE exposed workers and controls. IL10 plays a critical role in mediating the Th1/Th2 balance, apoptosis, and regulation of inflammation. Genotypes associated with altered IL10 expression have also been associated with the development and progression of NHL. Given that immunologic alterations are suspected to play a role in lymphomagenesis, and IL10 plays an important role in immunologic processes, our findings provide some support for the biologic plausibility that TCE is associated with lymphoma. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4646. doi:10.1158/1538-7445.AM2011-4646