Epidermolysis bullosa acquisita: report of a case with comparison of immunogold electron microscopy using pre- and postembedding labelling.

A patient with epidermolysis bullosa acquisita (EBA), who has been diagnosed as having bullous pemphigoid for 7 years, is reported. By immunoblotting, both the latest serum and a 4-year-stored serum sample of the patient, were shown to react with the 290-kDa EBA antigen or type VII collagen, but not with bullous pemphigoid antigens. Pre-embedding immunogold electron microscopy demonstrated that the serum bound to the 'anchoring plaque' and to both ends of the anchoring fibrils in the fashion reported previously. In contrast, postembedding immunoelectron microscopy showed binding mainly to the lamina densa. These results indicate that EBA antigens are localized mainly at the lamina densa. Further studies are necessary for confirmation.