RECENT ADVANCES IN ACQUIRED DISEASES AFFE CTING THE DERMOEPIDERMAL JUNCTION

The dermoepidermal junction (DEJ) is a supramolecular structure betwee n the epidermis and the dermis. Its importance in the integrity of the skin is evidenced by the numerous inherited and acquired diseases whi ch affect the DEJ and lead to subepidermal bullous disorders. Consider able progress has recently been made in the characterization of the mo lecules which constitute the basement membrane zone and of receptor/li gand interactions at the DEJ. Some molecules appear critical for the a dhesion of the epidermis to the dermis since a genetic alteration in t heir structure or an autoimmune reaction directed to these molecules u ltimately lead to dermal epidermal split and bullae formation. In resp ect to acquired bullous disorders, three molecules of the DEJ (bullous pemphigoid antigens (BP Ag 1 and BP Ag 2), collagen type VII and epil igrin/niceine) have been shown to be antigenic and are the targets of patients autoantibodies in three distinct diseases affecting the DEJ, namely bullous pemphigoid, epidermolysis bullosa acquisita and cicatri cial pemphigoid. The better understanding in the molecular basis of ac quired blistering skin diseases has already allowed the improvement of the diagnostic procedures and new insights in the nosology of this gr oup of dermatoses.