The role of immunohistochemistry in the diagnosis of the non-lethal forms of junctional epidermolysis bullosa.

Skin biopsies from four patients with similar clinical phenotypes of non-lethal junctional epidermolysis bullosa (JEB) were investigated by electron microscopy and immunohistochemistry. Electron microscopy revealed cleavage within the lamina lucida in each case, but in addition, there was considerable variability in the number and ultrastructure of hemidesmosome-anchoring filament complexes. Immunohistochemical staining of the dermal-epidermal junction, using monoclonal antibodies to laminin 5 and the 180-kDa bullous pemphigoid antigen, showed reduced laminin 5 staining with normal 180-kDa bullous pemphigoid antigen labelling in two cases, and reduced or absent 180-kDa bullous pemphigoid antigen staining with normal laminin 5 labelling in the other two cases. Whereas electron microscopy is invaluable for the diagnosis of JEB as a group of diseases, immunohistochemistry is able to provide insight into the molecular pathology of non-lethal JEB and reveal abnormalities in candidate genes and proteins underlying this group of genetic blistering disorders.