Lmmunohistochenical Study Of Skin-homing T Lymphocytes In The Skin Of Patients With Psoriasis Vulgaris

Immunohistochenical study of skin-homing T lymphocytes in the skin of patients with Psoriasis Vulgaris Currently, most dermatologists believe that psoriasis vulgaris is an immune-mediated skin disease. The infiltration of I lymphocytes play a central role in the initiation and persistence of the disease. The epitope identified by mAb HECA-452, cutaneous lymphocytes-associated antigen(CLA), defines a special T lymphocyte population with skin homing specificity. The purpose of this study was to investigate the expression of CLA on the skin infiltrating T lymphocytes and its ligand, E-selectin, in psoriatic skin in order to better understand the role of skin homing T lymphocytes in the development of psoriasis vulgaris. Applying indirect double immunofluorescent staining and immunoenzymatic staining (SP) techniques, we compared immunohistochemically the expression and the phenotypic profile of infiltrating CLAP T lymphocytes in normal (n= 10), uninvolved perilesional (n = 26) and lesional psoriatic (n 35) skin in different stages (progressing, stable or regressing) and normal human skin. We found that: 0 The majority of CD3~ T lymphocytes expressed CLA in normal human skin (approximately 79% ?9%), and the ratio of CLA~CD4t /CD4~ cells and CLA~CD8~ /CD8~ cells was 76%?3% and 83%?0%, respectively(P>0.05). ?In the lesions of psoriasis, approximately 80% ?16% CD3~ cells expressed CLA. Roughly similar subsets of both CD4 and CD8 T cells were CLA~, 85%?17% and 80%+ 11% respectively(P>0.05). ?In the lesions of PV, the number of CLA~CD4~ cells in progressive or stable stage outnumbered that in regressive stage (P <0.05). The number of CLA~CD4~ cells and CLA~CD8~ cells of uninvolved perilesional psoriatic skin in progressive stage was much more than that in stable stage (all P <0.05). 0 In the lesions of PV in different stages, there were significant differences in the intensity of expression of E-selectin(P 4 <0.05). The number of infiltrating CLA~ T cells were significantly correlated with the degree of expression of E-selectin on dermal microvessel in uninvolved perilesional and lesional psoriatic skin in every stage(all P<0.05). ~n both normal human skin and normal psoriatic skin, E-selectin was absent or only weakly expressed on dermal mircovessel. These results suggested that the majority of T cells were CLA~ T cells in normal human skin or psoriatic skin. In the progressive and stable psoriatic lesions, intraepidermal and dermal angiocentric T cells belonged predominantly to the CD45RO~CLA~CD4~ subset. So we further speculated that it might be CD45RO~CLA~CD4~ T cells that play an important role in the development and persistence of psoriasis valguris, but we could not exclude the role of CD45RO~CLA~CD84 T cells. The interaction of E-selectin and CLA play an important role in mediating T lymphocyte recruitment to the skin.