The basement membrane zone in lichen sclerosus: an immunohistochemical study.

The alteration in expression of basement membrane zone (BMZ) components in lichen sclerosus was investigated by immunohistochemical staining of skin biopsies from seven patients with histologically confirmed disease compared with controls. Monoclonal antibodies and polyclonal sera directed against proteins of the hemidesmosomes, anchoring fibrils, lamina lucida, lamina densa and BMZ collagens were used. Characteristic histological appearances at the dermo-epidermal junction were reflected in widespread alterations in antigen expression in the epidermal basement membrane and the papillary dermis. Expression of the proteins which constitute the structural scaffold (collagen IV and VII) were increased in lichen sclerosus. Expression of hemidesmosomal proteins which mediate adhesion and cell to matrix interaction (alpha 6 beta 4 and bullous pemphigoid antigen) and expression of anchoring filament components were markedly reduced, suggesting that the epidermal cells are exposed to selective damage.