RESPONSE OF GRAFTS FROM PATIENTS WITH ALOPECIA-AREATA TRANSPLANTED ONTO NUDE-MICE, TO ADMINISTRATION OF INTERFERON-GAMMA

A variety of evidence has pointed to immunological involvement in the pathogenesis of alopecia areata (AA). The aim of the present study was to determine whether differential expression of HLA-DR and intracellular adhesion molecules-1 (ICAM-1) occurs in hair structures of patients with longstanding AA, following stimulation with interferon-γ (IFN-γ). IFN-γ was injected i.v. to nude mice grafted with transplants obtained from affected areas of seven patients and of normal individuals. All mice were injected with IFN-γ or phosphate-buffered saline (PBS) alone for 3 consecutive days. Immunohistochemical studies were performed in specimens of grafts in order to detect the change in adhesion molecules, HLA-DR antigen, and Langerhans cells. ICAM-1 and HLA-DR induction was found to be similar in grafts from AA patients and normal skin grafts in the IFN-γ injected mice. However, more intraepithelial Langerhans cells were observed in the AA patients’ grafts treated with INF-γ than in those treated with PBS and in normal grafts treated with INF-γ. This study suggests an important role of Langerhans cells in this issue. © 1993 Academic Press.