Cytokine expression and cytokine-based T-cell profiling in occupational medicamentosa-like dermatitis due to trichloroethylene

Early diagnosis and treatment of occupational medicamentosa-like dermatitis due to trichloroethylene (OMLDT) are absence of specific and reliable diagnostic/therapeutic biomarkers. This study was conducted on 30 cases of OMLDT, 58 workers exposed to trichloroethylene (TCE) and 40 unexposed controls in order to identify any cytokine signatures that give an index to CD4+T cell differential and serve as biomarkers of OMLDT. Expression profiles of Th1, Th2, Th17 and Treg cell type-specifying transcription factors and cytokines were analyzed using real time quantitative PCR (RT-qPCR) assay. To explore whether such expression profiles reflected their steady state plasma levels, a Luminex liquid fluorescence analysis was conducted. We found that the expression of transcription factors FoxP3 transcription factors (P = 0.006 and P < 0.0001) and IL-10 cytokine (P = 0.0008 and P < 0.0001) of the Treg subset were significantly higher in patients than TCE exposure workers and unexposed controls, suggesting that Treg cells were active after the occurrence of OMLDT. The transcript levels of IL-6 were significantly lower in the TCE exposure groups including patients and exposure workers as compared to the unexposed controls (P < 0.0001 and P = 0.0008). Circulating levels of assessed cytokines of IL-6 (P = 0.001 and P = 0.011) and TFN-α (P = 0.005 and P < 0.0001) were lower in the exposure groups than in the unexposed controls. Compared to the controls, the levels of IL-10 in patients were higher (P = 0.001 and P = 0.0008). There was a significantly positive correlation between the plasma levels IL-6 and IL-10 in TCE exposed workers. These alterations in the expression of transcription factors and cytokines highlight the underlying dysregulation of T cell subsets in OMLDT that reflect an immune tolerance or immune inhibition. Therefore, the elevation of IL-10 level may be a kind of pathogenesis indicator, and the decline in IL-6 level may be a kind of TCE exposure biomarker. These biomarkers need additional longitudinal follow-up studies to warrant to clinically useful biomarkers of OMLDT.