Objective:To analyze the relationship between PPD and MF on the basis of the surface antigen CD4

CD8 and receptor γ of T cell

so as to provide if PPD can represent a cutaneous lymphoid dyscrasia.Methods:The expression of CD4 and CD8 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 with PCR.Results: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+.In the dermis

the numbers of CD4+ 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+ and 9 cases have atypicalerythfra.Conclusions:PPD have 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 feature of mycosis fungoides.