Collagen XVIII and fibronectin involvement in bullous scleroderma

Endostatin, an anti-angiogenic C-terminal fragment of collagen XVIII, has been recently reported to play a role in scleroderma pathogenesis, but collagen XVIII immunohistochemistry in scleroderma skin has still not been performed. Bullous scleroderma, a rare form of scleroderma, may have altered angiogenic and lymphangiogenic characteristics.

Our aim is to report a rare case of bullous scleroderma, studying the presence of fibronectin and collagens type I, III and XVIII in sclerodermic skin.

We describe the progression of bullous scleroderma in a 67-year-old patient since the first symptoms. Histological and immunohistochemical aspects of skin biopsies are compared to normal skin from a patient without scleroderma and are correlated with the pathogenesis of the disease. Indirect immunofluorescence measured by laser confocal microscopy allows quantitative determination of fibronectin and collagens type I, III and XVIII.

Dermo-epidermal cleavage, fibrosis and inflammation are the main histological findings. The dermal distribution and amounts of collagens and in the scleroderma patient are similar to normal skin. Conversely, both fibronectin and collagen XVIII are increased in scleroderma skin, suggesting their involvement in the pathogenesis of bullous scleroderma.