A quantitative analysis of the Langerhans cell in chronic plaque psoriasis.

Abstract

Summary The mouse monoclonal antibody, NAI/34, in a standard immunoperoxidase technique, was used to count Langerhans cells in skin obtained from nine patients who were suffering from chronic plaque psoriasis. Biopsies were obtained from involved skin, clinically uninvolved skin and clinically healed skin following treatment with tar and/or dithranol. Langerhans cell numbers were expressed both as the absolute number of Langerhans cells per linear millimetre of surface epidermis and also as the number of Langerhans cells overlying 200 basal cells. An analysis of variance showed that in the active edge of a plaque of psoriasis, the absolute number of Langerhans cells was increased compared to adjacent uninvolved skin but when expressed as a ratio relative to the number of basal cells present, the number was decreased. This ratio returned to normal in healed skin. The ratio of Langerhans cells to basal cells in clinically uninvolved and in healed skin is the same ratio as we have found in over 100 specimens of normal skin obtained from non-psoriatic individuals.