Langerhans Cells in Epidermodysplasia verruciformis

T cell defect and anergy to contact sensitizers are characteristic of the depressed cell-mediated immunity in epidermodysplasia verruciformis (EV). In this disease the generalized infection with human papilloma viruses is associated with a high risk of skin cancers. Langerhans cell density was studied quantitatively in lesions and noninvolved epidermis of EV using OKT6 and anti-HLA-DR monoclonal antibodies with indirect immunofluorescence technique. No significant changes were found in apparently normal skin suggesting no primary defect of Langerhans cells in EV. A marked decrease in Langerhans cell number per unit of epidermal volume could be observed in EV lesions. This additional reduction of immunological surveillance at sites of potentially oncogenic human papilloma virus infection may contribute to the increased risk of malignant transformation in EV lesions.