The Dis-balance Of Tc Cells And Discordant Expression Of Apoptotic Proteins In The Pathogenesis Of Photosensitizing Dermatitis

Objective To investigate the association of the dis-balance of Tc1 and Tc2 cells and discordant expression of apoptotic proteins with chronic actinic dermatitis(CAD) and polymorphic light eruption(PLE).Methods The subgroup of infiltrated cells and the expression of receptors of Interleukin-4(IL-4), Interleukin-10(IL-10), Interleukin-12(IL-12) and Interferon-r (IFN-r) in these cells of the eruptions from 28 patients with CAD and 8 patients with PLE and 7 normal control are tested by immunohistochemistry(S-P method). The expression of apoptotic proteins in the keratinocytes also studied. The amount of IL-4,IL-10,IL-12 and IFN-r in serum from 33 patients with CAD and 23 patients with PLE and 32 normal control were tested by ELISA.Results The results showed that l.The major infiltrated cells in the eruptions of the patients with CAD and PLE patients are T cells compared with B cells (p<0.001 or p=0.001). 2.In these T cells, the Tc cells are predominant compared with Th cells (p<0.001 or p=0.001). 3.Most of these infiltrated cells express receptors of IL-12 and IFN-r compared with the expression of IL-4 and IL-10 receptor (p<0.001).4.The serum level of IL-12 and IFN- r from patients with CAD and IL-12 from PLE are significantly increased, compared with control group (p=0.034,0.004,0.015 respectively). 5.Compared with the normal epidermis, Bcl-x1 and Fas-1 are significantly overexpressed in the upper part of straum spinosum from the CAD and PLE (pO.OOl) Conclusions These findings indicate the dis-balance of Tc1 and Tc2 cells probably plays an important role of etiology and pathogenesis in the CAD and PLE. Much higher expression of Bcl-xl and Fas-1 might contribute to the antiapoptotic response in keratinocytes.