Expression of CD1a and CD86 on scleroderma Langerhans cells.

Scleroderma is a chronic autoimmune connective tissue disorder of unknown etiology that affects the microvasculature and loose connective tissue. Langerhans cells play an important role in the immune system of the skin. By immunohistochemistry we investigated the phenotypical characteristics of epidermal and dermal Langerhans cells and their spatial relationship with infiltrating lymphocytes in systemic scleroderma (SSc) and localized scleroderma. Skin samples were obtained from patients by 6 mm punch biopsy. Samples were stained with antibodies against CD1a and CD86. The number of cells stained with both antibodies in the dermal and epidermal infiltration was calculated. In contrast to normal skin, both types of scleroderma skin showed a marked increase in CD1a+ dermal Langerhans cells, whereas the number of CD1a+ cells in localized scleroderma was much higher than that in SSc (p < 0.05) either in the dermis or in the epidermis. The expression of CD86 was increased in the dermis of localized scleroderma compared with that in SSc or normal skin (p < 0.05). This study revealed that Langerhans cells may play an important role in the pathogenesis of scleroderma, especially in localized scleroderma. CD86 is predominantly expressed on dermal Langerhans cells in the lesional skin of localized scleroderma. Therefore, it might play an important role in the pathogenesis of localized scleroderma.