Increased density of CD1a^+ Langerhans cells and CD86+ cells in perilesional and lesional psoriatic skin: an immunohistochemical study

Background psoriasis is a long-lasting autoimmune disease mediated by t-lymphocytes and dendritic cells (dc). cd1a^+ is a dc marker. cd86^+ is a well-known activation marker of the dc (costimulatory molecule). it is hypothesized that the development of chronic plaque psoriasis is associated with alterations of dc. objective to characterize cd1a+ and cd86^+ cells in chronic plaque psoriasis. patients and methods monoclonal antibodies against cd1a^+ and cd86+ were used for immunohistochemical evaluation of these molecules in the lesional and perilesional skin obtained from 30 psoriatic cases. five cases represented the control group (healthy skin). results we found significant variations in the density of cd1a^+ and cd86^+ cells among the control skin compared with the perilesional and lesional psoriatic skin. there was an increased density of cd1a^+ langerhans and cd86^+ dc in the perilesional and lesional psoriatic skin compared with healthy skin. higher counts of cd1a+ langerhans cells in the epidermis and cd86^+ cells in both epidermis and dermis of the perilesional psoriatic skin were observed compared with lesional ones. conclusion the prominent density of cd1a^+ and cd86^+ dc in the perilesional skin compared with the lesional psoriatic skin suggests the pathogenetic role of these cells in the initiation of plaque psoriasis. the simultaneous presence and close localization of cd1a ^+ and cd86^+ cells in the psoriatic dermal and epidermal compartments suggests that their interaction potentially contributes to the development of psoriasis.