Molecular identification of major and minor bullous pemphigoid antigens.

The skin antigens defined by basement membrane zone antibodies in 38 patients with bullous pemphigoid were analyzed by Western immunoblot. Thirty-four patients (89%) had antibodies to a major bullous pemphigoid antigen with a molecular weight of approximately 230 kD. Twelve patients (32%) had antibodies to a minor bullous pemphigoid antigen with a molecular weight of approximately 160 kD; this included four patients who did not have antibodies to the 230 kD antigen. Depending on the epidermal extract used, a variable number of patients (up to 75%) also had antibodies to minor bullous pemphigoid antigens with molecular weights of approximately 180 and 200 kD. The results of this study confirm that bullous pemphigoid antigens are heterogeneous at the molecular level. Approximately 10% of patients have antibodies directed solely to a minor bullous pemphigoid antigen.