Dendritic Antigen Presenting Cells in the Pathogenesis of Psoriasis

Overview

Background:
In the last years, psoriasis is by a greater number of authors considered as T-cellmediated disease of autoimmune nature. Dendritic cells, namely these expressing FXIIIa, representone of the three most proliferative cell population in psoriatic lesional skin. Because these cells arecapable to present antigen to T-cells, it is probable, that they can play a role in the pathogenesis ofpsoriasis. In the literature described alterations of epidermal basement membrane structures canbe the basis of penetration of such cell subtypes in the epidermis, which, under normal conditions,there are not present.Objective: To verify if the presence of dendritic CA1a-/Fc
RI-DR+CD68+FXIIIa+ cells in the psoriaticlesional epidermis and dermis, in comparison with perilesional psoriatic skin and other dermatosisand healthy control, is characteristic feature of psoriasis. To verify if the potential alterationsof epidermal basal membrane integrity are in relation to the presence of this subtype of dendriticcells.Methods: Simple and double-labelling imunofluorescence technique with the use of labelledantibodies were used in identification of these cell subtypes in patients with psoriasis, morphea,systemic scleroderma, atopic eczema and healthy controls. Results: Dendritic CD1a-/Fc
RI-DR+CD68+FXIIIa+ cells were present only in the psoriatic epidermis.Alterations of epidermal basement membrane were not found.Conclusions: The presence of dendritic CD1a-/Fc
RI-DR+CD68+FXIIIa+ cells in the psoriaticepidermis and their absence in the epidermis of other investigated dermatoses support the hypothesisof their, otherwise not specified, pathogenetic role in the pathogenesis of this disease. Alterationsof the epidermal basement membrane integrity were not confirmed, probably because of notsufficiently sensitive technique used for its detection.

Key words:
psoriasis - epidermis - dendritic CD1a-/Fc
RI-DR+CD68+FXIIIa+ cells