THE BASEMENT-MEMBRANE ZONE IN LICHEN-SCLEROSUS - AN IMMUNOHISTOCHEMICAL STUDY

The alteration in expression of basement membrane zone (BMZ) component s in lichen sclerosus was investigated by immunohistochemical staining of skin biopsies from seven patients with histologically confirmed di sease compared with controls, Monoclonal antibodies and polyclonal ser a directed against proteins of the hemidesmosomes, anchoring fibrils, lamina lucida, lamina densa and BMZ collagens were used, Characteristi c histological appearances at the dermo-epidermal junction were reflec ted in widespread alterations in antigen expression in the epidermal b asement membrane and the papillary dermis, Expression of the proteins which constitute the structural scaffold (collagen TV and VII) were in creased in lichen sclerosus. Expression of hemidesmosomal proteins whi ch mediate adhesion and cell to matrix interaction (alpha 6 beta 4 and bullous pemphigoid antigen) and expression of anchoring filament comp onents were markedly reduced, suggesting that the epidermal cells are exposed to selective damage.