Anatomical distribution and immunological characteristics of epidermolysis bullosa acquisita antigen and bullous pemphigoid antigen.

A Japanese patient with epidermolysis bullosa acquisita (EBA) was autopsied, and direct immunofluorescence (DIF) testing was performed. Using this patient's serum (EBA serum) and three bullous pemphigoid (BP) sera, the anatomical distribution and immunological characteristics of EBA antigen and BP antigen were investigated by indirect immunofluorescence (IIF). EBA antigen showed the same anatomical distribution as BP antigen in DIF and IIF studies; both antigens were limited to the skin, tongue, oesophagus, trachea, cornea and bladder. EBA antigen was located on the dermal side of both NaCl and PBS-separated skin, whereas BP antigen was limited to the epidermal side. Ethanol fixation abrogated the antigenic stability of BP antigen, but not that of EBA antigen. No difference was found when acetone or formalin fixation was used. The separation methods and prefixation in ethanol could be useful techniques applicable to the classification of the bullous disorders which manifest circulating anti-BMZ antibodies.