Identification of the skin basement-membrane autoantigen in epidermolysis bullosa acquisita.

Epidermolysis bullosa acquisita is an acquired chronic blistering disease of the skin, in which separation of the skin occurs in the basement-membrane zone between the epidermis and the dermis. There is evidence that blistering is initiated by an immune process. Using serum samples from nine patients as a source of antibodies, we have identified a major protein of the basement membrane of human skin that serves as the antigen (or target) for autoantibodies in this disorder. This previously unrecognized protein, which consists of two components of 290,000 and 145,000 daltons, is distinct from other known components of the basement membrane. These studies provide evidence that epidermolysis bullosa acquisita is a specific disease that is different from other primary bullous diseases, such as bullous pemphigoid and pemphigus vulgaris, and suggest that the basement-membrane component that has been identified may have a role in normal epidermal-dermal adherence.