Immunohistologic studies in Schamberg's disease. Evidence for cellular immune reaction in lesional skin.

We studied eight cases of Schamberg's disease immunohistologically by using monoclonal antibodies. The dermal infiltrate was composed of Leu-1-reactive T cells, OKT6-reactive Langerhans' cells, and Leu-M5-reactive (Leu-M5+) macrophages. Among them, the major population consisted of T cells with the predominance of Leu-3a-reactive (Leu-3a+) T cells over Leu-2a-reactive (Leu-2a+) T cells. On the other hand, the epidermotropic mononuclear cells consisted of Leu-2a+ and Leu-3a+ T cells without any predominant pattern, and Leu-M5+ macrophages. Furthermore, note that a pemphiguslike intercellular staining pattern was observed in the epidermis in most of the cases, when the sections were stained either with anti-HLA-DR antibody or with OKT6, suggesting the HLA-DR antigen expression on the keratinocyte surface and possibly an enlargement of Langerhans' cells. Based on these immunohistologic findings, we think that Langerhans' cells play an important role in the pathomechanism of Schamberg's disease, and that cellular immune reactions are taking place in the lesional skin.