Cell Adhesion Molecules as Targets of Autoantibodies in Pemphigus and Pemphigoid, Bullous Diseases Due to Defective Epidermal Cell Adhesion

Abstract

This chapter focuses on cell adhesion molecules as targets of autoantibodies in pemphigus and pemphigoid, bullous diseases. In various autoimmune blistering diseases of skin, autoantibodies are directed against epidermal cell adhesion molecules or molecules found in cell adhesion junctions. The blisters and dysfunction of the epidermal barrier in these diseases result from loss of adhesion of cells either to the basement membrane or to other cells. This theme is developed for three diseases, bullous pemphigoid (BP), pemphigus foliaceus (PF), and pemphigus vulgaris (PV). Studies of the autoantibodies from patients with these diseases have shed light on potential pathophysiologic mechanisms and have enabled the start of the understanding of the way the epidermis maintains its intact state. BP, PF, and PV are all bullous diseases of skin. Each has a distinctive clinical appearance and the blisters in each result from loss of adhesion at a specific level of the epidermis. BP and pemphigus also have characteristic immunofluorescence findings; however, the immunofluorescence findings in PF and PV are very similar. BP is a subepidermal blistering disease in which autoantibodies localize to the site of pathology and define a normal antigen of stratified squamous and complex epithelial basement membranes.