Immunoelectron microscopic study of the basement membrane in oral lichen planus.

The present study investigated the nature of basement membrane changes in oral lichen planus. For this purpose antibodies to type IV collagen, laminin and fibronectin were applied in avidin-biotin peroxidase complex staining using a pre-embedding immunoelectron microscopy technique. Immunoreactivity to type IV collagen and laminin was restricted to the sub-basal basement membrane and the basement membrane branches extending into the lamina propria. Immunoreactivity to fibronectin was noted also in the connective tissue as a network-like arrangement of thin strands. Although local activated CDB+ cytotoxic lymphocytes and tissue macrophages may be involved in the local pathogenetic process, these findings suggest that the basement membrane alterations are secondary to pathologic changes in the basal cells.