THE DERMOEPIDERMAL JUNCTION AND ITS ACQUIRED AND INHERITED DISEASES - A FEW RECENT ADVANCES

The dermoepidermal junction (DEJ) is a key structure in the skin. Many acquired and inherited diseases affect the DEJ. New insight has been gained into the chemical composition of the DEJ of which at least 20 protein components have been identified to date. Some components of hemidesmosomes, which are critical DEJ structures, have also been identified. Hereditary epidermolysis bullosa is a heterogeneous group of DEJ disorders. Studies are beginning to shed light on the molecular mechanisms of these diseases. Dystrophic epidermolysis bullosa is due to alterations in the collagen IV molecule which is an essential component of anchoring fibrils. Several molecules, including BM-600 niceine, are apparently altered in the skin and other epithelia of patients with junctional epidermolysis bullosa. These molecules may be involved in the pathogenesis of inherited DEJ diseases with anomalies of hemidesmosomes. Lastly, DEJ antigens involved in a number of acquired bullous skin disorders (bullous pemphigoid, herpes gestationis, acquired epidermolysis bullosa...) have been identified recently.