Defective IL-2 receptor expression in lymphocytes of patients with arsenic-induced Bowen’s disease

The immune function of peripheral mononuclear cells (MNC) in patients with endemic arsenic-induced Bowen's disease (BD) was investigated. Many cytokines and immune-related factors were determined in the present study. Interleukin-1β and TNF-α production was used as an indicator of monocyte/macrophage function. Il-2 and sIL-2R production was used as an indicator of lymphocyte activation. The release of sCD4 and sCD8 was used as an indicator of activation of respective T-cell subpopulations. Production of IFN-γ and IL-2 reflected the cellular effector function of helper T-cells type 1. In vivo cell-mediated immunity was also assessed by estimation of the percentage of T-cells in peripheral blood MNC and the nonspecific delayed-type hypersensitivity (DTH) response to 2,4-dinitrochlorobenzene (DNCB). Both assays revealed depressed cell-mediated immunity in BD. Compared with healthy controls, spontaneous and PHA-induced IFN-γ and TNF-α production was significantly decreased in BD whereas spontaneous release of IL-2, sCD4 and sCD8 was significantly increased. Although PHA stimulation increased IL-2 release, the expression of IL-2R α and β chains and the release of sIL-2R were not proportionately increased in BD. In addition, IL-2-mediated [ 3 H]-thymidine incorporation by MNC in patients with BD was significantly decreased. These findings suggest that the defective cell-mediated immune function in BD is due to impairment of membrane IL-2R expression in lymphocytes after stimulation.