LANGERHANS CELLS IN PRURIGO NODULARIS INVESTIGATED BY HLA-DR AND S-100 IMMUNOFLUORESCENCE DOUBLE STAINING

The Langerhans cell is one of the antigen-presenting cells in the immu ne system. To study the presence of cutaneous Langerhans cells in prur igo nodularis, age-and sex-matched prurigo nodularis patient and healt hy volunteer skin biopsies were investigated by an HLA-DR and S-100 im munohistochemical double staining method. The results showed that the HLA-DR-and S-100-immunoreactive (IR) Langerhans cells were altered in prurigo nodularis epidermis and dermis. The number of epidermal Langer hans cells in the prurigo nodularis patients was decreased in five and increased in two cases. In the dermis, the HLA-DR-and S-100-IR cells were apparently more numerous than in the controls. In the involved sk in there were also more S-100-IR coarse nerve fibres in the dermis as compared to controls. The results indicate that dermal Langerhans cell s (HLA-DR and S-100 double-labeled) as well as other dermal KLA-DR-and S-100-IR dendritic cells, but most likely not epidermal Langerhans ce lls, may be critically involved in the development or persistence of p rurigo nodularis. (C) 1998 Elsevier Science Ireland Ltd. All rights re served.