[Vitronectin in normal human skin and in skin lesions]

Vitronectin (S-protein of complement, serum spreading factor) is a multifunctional glycoprotein present in human plasma and in the elastic tissue of various organs. It belongs to the group of adhesion proteins and is of importance in the terminal stages of both the coagulation and complement system and in fibrinolysis. In human skin it is localized on dermal elastic fibers and on pathologically altered elastic material (solar elastosis, pseudoxanthoma elasticum) as well as on keratin filament material such as keratin bodies in lichen planus or amyloid deposits in localized cutaneous amyloid. It is also found in the abnormally thickened cutaneous blood vessels in erythropoietic protoporphyria and porphyria cutanea tarda. Late-stage inhibition of the complement cascade in bullous disorders in which activation of the complement system is of pathogenetic significance may be an additional important function of vitronectin in skin diseases.