EPIDERMOLYSIS-BULLOSA ACQUISITA ASSOCIATED WITH EPIDERMAL-BINDING CIRCULATING ANTIBODIES

Epidermolysis bullosa acquisita (EBA) is a rare, immunobullous disease , characterized by circulating and tissue-bound antibodies against typ e VII collagen (C7) of anchoring fibrils in the cutaneous basement mem brane zone, These antibodies localize to the dermal aspect of salt-spl it skin on indirect and direct immunofluorescence (IMF), We report two patients with clinical features of EBA, in whom circulating IgG antib odies bound to the epidermal aspect of salt-split skin, In both patien ts direct IMF of salt-split perilesional skin revealed dermal IgG depo sits, and direct immunogold immunoelectron microscopy showed antibody deposits in the region of anchoring fibrils, Their serum failed to rea ct with epidermal or dermal extracts on Western immunoblotting. Epider mal-binding antibodies have not been reported previously in associatio n with EBA, and the IMF findings in these cases suggest the developmen t of autoantibodies to additional epidermal-associated antigens, Targe t antigen heterogeneity has been reported in most other immunobullous diseases, and may be a hitherto unrecognized feature of EBA.