19-DEJ-1, a hemidesmosome-anchoring filament complex-associated monoclonal antibody. Definition of a new skin basement membrane antigenic defect in junctional and dystrophic epidermolysis bullosa.

Abstract

A murine monoclonal antibody (19-DEJ-1) was recently produced that recognizes a unique antigenic epitope of human skin basement membrane localized to the midlamina lucida exclusively in those areas bordered by overlying hemidesmosomes. To determine whether the antigen defined by 19-DEJ-1 is normally expressed in one or more forms of epidermolysis bullosa (EB) known to have structural and antigenic defects in skin basement membrane, we examined by indirect immunofluorescence 46 specimens of clinically normal skin from 43 patients representing each of the four forms of inherited EB (simplex, 15 patients; junctional, nine patients; dominant dystrophic, seven patients; and recessive dystrophic, 15 patients). All nine junctional EB specimens revealed absent 19-DEJ-1 binding; similarly, seven of 15 and one of six recessive and dominant dystrophic EB skin specimens, respectively, showed lack of antibody recognition. In contrast, binding was normal in 15 of 15 EB simplex specimens and five of six dominant dystrophic EB specimens. Absent binding of 19-DEJ-1 to junctional EB skin correlates well with the localization of this antigen to the region of the midlamina lucida. Its absence in approximately 50% of patients with recessive dystrophic EB further suggests, for the first time, that an inherited defect in basement membrane is shared in patients with junctional and some recessive dystrophic EB. The difference in site of skin cleavage in the latter two disorders gives additional support to the hypothesis that 19-DEJ-1 recognizes a structure, such as the anchoring filament, which both bridges the entire basement membrane and contributes to epidermal-dermal adhesion.