Studies on fibronectin in the skin: VI. Intra-epidermal depositions in vulgar psoriasis, lupus erythematosus, bullous pemphigoid and dermatitis herpetiformis.

The fibronectins are a group of glycoproteins present in plasma and cellular tissues. They are produced by fibroblasts and endothelial cells, and are of importance in cellular adhesion and spreading. Fibronectin has a special affinity to fibrous proteins such as collagen and elastin, and is abundantly present in normal skin in the dermo-epidermal junction area, dermis, and subcutis. Fibronectin is not found in the epidermis. In a number of diseases fibronectin can be demonstrated in the epidermis of lesional skin, with or without affection of the dermo-epidermal junction area. Such changes are found in psoriasis vulgaris, lupus erythematosus, bullous pemphigoid and dermatitis herpetiformis, and represent the exoserosis of plasma and/or transepidermal elimination of degenerated tissue structure with fibronectin from the dermo-epidermal junction and the papillary dermis.