Identification of an epidermal basement membrane defect in recessive forms of dystrophic epidermolysis bullosa by LH 7:2 monoclonal antibody: use in diagnosis.

LH 7:2 is a monoclonal antibody that was raised against an extract of human epidermal cells and identifies an epitope within the lamina densa of the basement membrane of stratified squamous epithelia. Using indirect immunofluorescence we found intense labelling with LH 7:2 at the epidermal basement membrane (EBM) of normal skin, and in skin samples from patients with simplex, junctional, dominantly inherited dystrophic and acquired forms of epidermolysis bullosa (EB), as well as bullous pemphigoid. Staining was absent or only very faint in generalized recessive dystrophic EB (RDEB), and patchily reduced in the localized form of RDEB. We conclude that LH 7:2 recognizes an EBM antigen which may be important in the pathogenesis of RDEB. Moreover, the antibody provides a useful probe for the rapid diagnosis of RDEB and is of special value in helping to discriminate between localized RDEB and typical dominant dystrophic EB--conditions which closely resemble each other clinically and which cannot be distinguished by means of transmission electron microscopy.