Expression Of CD4, CD8 And Receptor γ Of T Cell In Pigmented Purpuric Dermatoses

Objective To analyze the relationship between PPD and MF on the basis of the surface antigen CD4 , CD8 and receptorγof T cell ,so as to provide if PPD can represent a cutaneous lymphoid dyscrasia.Methods The expression of CD4+ T cell and CD8+ T cell was measured by immunohistochemical technique in specimens obrained from lesional skin of 23 cases of PPD, 20 cases of MF and skin of 20 cases of normal persons. The TCR gamma gene rearrangement was detected by PCR.Results 23 cases of PPD show small lymphocytes infiltration mainly. 15 cases of PPD have obvious migrations of lymphocytes to the epidermis. Their 5 cases and 20 cases of MF show T cell epidermotopism; 18 cases of PPD, 20 cases of MF and 6 cases of normal persons show a dominance of CD4+ T cell.In the dermis, the numbers of CD4+ T cell between PPD and MF are 38.2±30.6 and 68.8±47.6 ( P<0.017),and the ratios of CD4+/CD8+ are 1.7±1.1 and 2.6±0.8(P<0.05).Both have significant differences.The remains are no obvious differences.TCR gamma gene rearrangement was found in 10 cases of PPD and 16 cases of MF.7 cases of PPD can be seen obvious migrations of lymphocytes to the epidermis(including 3 cases characterized by epidermotopism), 8 cases show a dominance of CD4+ T cell and 9 cases have atypicalerythfra.Conclusions PPD have some similar feature like mycosis fungoides,so it may be one kind of cutaneous lymphoid dyscrasia. We should pay attention to follow the patients with widespread erythra,bad curative effect and similar immunophenotyping and molecular features of mycosis fungoides.