[Anti-p200 pemphigoid--a new bullous autoimmune dermatosis]

Anti-p200 pemphigoid is an autoimmune skin disease characterized by tense blisters, subepidermal split formation, and mainly neutrophilic inflammatory infiltration of the dermal-epidermal junction (DEJ). Direct immunofluorescence microscopy of perilesional skin biopsies demonstrates linear deposits of IgG and C3 along the DEJ, while by indirect immunofluorescence microscopy on NaCI-split human skin, patients' IgG labels the dermal side. The antigenic target of the autoantibodies is a 200 kD protein (p200) of the lower lamina lucida that can be detected in human dermal extracts by immunoblotting. While p200 is thought to be important for cell-matrix adhesion, its exact identity is unknown. To date, the p200 autoantigen has been demonstrated to be distinct from bullous pemphigoid antigens 180 und 230, laminin 1, 5, and 6, alpha6beta4 integrin, and type VII collagen. Biochemical characterization of the p200 molecule revealed a noncollagenous N-glycosylated acidic protein with an isoelectric point of approximately 5.5. We provide an overview on pathogenesis, clinical features, diagnosis, and treatment of this unique autoimmune dermatosis.