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 i dentified plectin/HD1 mutations in epidermolysis bullosa simplex patients s uggest that defective expression of BP230 and plectin/HD1 may predispose to blister formation in human skin. We have studied the expression of the epi thelial adhesion complex as well as the basement membrane and anchoring fib ril antigens in uninvolved dermatitis herpetiformis skin to find out if alt erations can be detected in these structures predisposing to the blister fo rmation typical of the disease. Ten uninvolved dermatitis herpetiformis ski n specimens, which all showed clear granular deposits of IgA under the base ment membrane in direct immunofluorescence and five normal skin specimens, were studied by indirect immunofluorescence technique. Six uninvolved derma titis herpetiformis skin specimens showed distinctly decreased immunoreacti on for BP230 and four uninvolved dermatitis herpetiformis skin specimens sh owed distinctly decreased immunoreaction for plectin/HD1. All five skin con trols showed strong immunoreactions for BP230 and plectin/HD1. Other hemide smosomal proteins including BP180 and integrin alpha 6 beta 4, as well as b asement membrane proteins laminin-5, laminin-1, nidogen and type IV collage n, and the anchoring fibril protein type VII collagen showed a normal stron g expression. Our results suggest that alterations in BP230 and plectin/HD1 may contribute or predispose to blister formation in dermatitis herpetifor mis skin.