Ultrastructural features of Langerhans cells in clinically uninvolved skin of psoriatics.

Epidermal Langerhans cells (LC) from skin of clinically normal appearance in psoriatics were studied electron microscopically and compared with LC from the skin of healthy volunteers and from those with other dermatoses. Results show that LC from psoriatics display partly distinct cytoplasmic alterations. Moreover, about half of LC investigated were partly or mainly surrounded by clearly widened intercellular spaces, such that an immediate cellular contact with neighbouring keratinocytes was correspondingly decreased. Whether such LC are functionally altered remains to be clarified.