Abstract: Objective To study the relationship between the in situ expression of infiltrating T lymphocyte subsets and leukocyte adhesion molecules in psoriatic patients. Methods Immunohistochemical technique was employed to study the expression of infiltrating T lymphocyte subsets (CD3, CD4, CD8) and leukocyte adhesion molecules (ICAM-1, ELAM-1, VCAM-1) in the lesional and non lesional psoriatic skin. Results There was a significant increase of T lymphocyte subsets (CD3, CD4 and CD8) and adhesion molecules (ICAM-1, ELAM-1, VCAM-1) in the lesional skin than those in non lesional skin in psoriasis, and that there is a significant positive correlation between the density of infiltrating T lymphocyte subsets and the intensity of in situ expression of adhesion molecules. In comparison to the materials from normal controls, the upregulation expression of adhesion molecules was observed in non-lesional skin and normal appearance skin after short duration topical treatment with corticosteroid. Conclusion Increased upregulation expression of adhesion molecules is closely associated with the infiltration of T lymphocytes in lesional skin of psoriasis and may be one of the factors for the recurrence of psoriasis.

Key words: Psoriasis, Cells,endothelium vascular, Cell adhesion molecules, T lymphocytes