A CASE OF UNIQUE SUBEPIDERMAL BLISTERING DISEASE WITH AUTOANTIBODIES AGAINST A NOVEL DERMAL 200-KD ANTIGEN

Background: Several autoimmune subepidermal blistering diseases with a utoantibodies against the epidermal basement membrane zone (BMZ) have been identified, Each shows distinct immunological findings. Objective s: Our patient showed clinical features which were indicative of bullo us pemphigoid or linear IgA bullous dermatosis, In his serum, circulat ing IgG antibodies binding to the dermal side of skin split with 1 M N aCl were detected. To clarify the immunological character of the patie nt, we performed further studies. Methods: Western immunoblot analysis using normal human skin extracts and indirect immunofluorescence (IF) with affinity-purified IgG antibodies to the detected dermal protein were done, Results: Western immunoblot analysis demonstrated IgG antib odies reacting with a dermal 200-kD protein. Affinity-purified Ige ant ibodies to the 200-kD protein reacted to the dermal side of the split by indirect IE Therefore, this dermal 200-kD protein is believed to be the epidermal BMZ antigen, Conclusion: Our patient showed an immunolo gically unique subepidermal blistering disease.