Hemidesmosomal molecular changes in dermatitis herpetiformis; decreased expression of BP230 and plectin/HD1 in uninvolved skin.

Recent BP230-knockout experiments with subsequent blistering and recently identified plectin/HD1 mutations in epidermolysis bullosa simplex patients suggest that defective expression of BP230 and plectin/HD1 may predispose to blister formation in human skin. We have studied the expression of the epithelial adhesion complex as well as the basement membrane and anchoring fibril antigens in uninvolved dermatitis herpetiformis skin to find out if alterations can be detected in these structures predisposing to the blister formation typical of the disease. Ten uninvolved dermatitis herpetiformis skin specimens, which all showed clear granular deposits of IgA under the basement membrane in direct immunofluorescence and five normal skin specimens, were studied by indirect immunofluorescence technique. Six uninvolved dermatitis herpetiformis skin specimens showed distinctly decreased immunoreaction for BP230 and four uninvolved dermatitis herpetiformis skin specimens showed distinctly decreased immunoreaction for plectin/HD1. All five skin controls showed strong immunoreactions for BP230 and plectin/HD1. Other hemidesmosomal proteins including BP180 and integrin alpha6beta4, as well as basement membrane proteins laminin-5, laminin-1, nidogen and type IV collagen, and the anchoring fibril protein type VII collagen showed a normal strong expression. Our results suggest that alterations in BP230 and plectin/HD1 may contribute or predispose to blister formation in dermatitis herpetiformis skin.