Recent Advances in the Molecular Pathology of Bullous Skin Disorders

Maintenance of an intact epidermis depends on secure adhesion between adjacent keratinocytes and between basal keratinocytes and underlying epidermal basement membrane. The major adhesion units that achieve this are the hemidesmosomes and desmosomes but when these structures are disrupted, for example by gene mutations or autoantibodies, the resilience of the epidermis is lost and blisters develop. Recently, there have been considerable advances in our understanding of the complex proteins and glycoproteins that contribute to maintaining keratinocyte adhesion via hemidesmosomes and desmosomes, as well as new insight into the molecular pathogenesis of several inherited and autoimmune blistering skin diseases. These new basic scientific data are clinically relevant, helping to improve patient management as well as providing a rationale for developing better and more specific treatments for patients with inherited or acquired blistering skin diseases. This review provides an update on the new information about the molecular pathology of hemidesmosomes and desmosomes that result in bullous skin diseases.