Immunopathologic changes in 115 patients with bullous pemphigoid

Abstract

Bullous pemphigoid (BP) is an autoimmune bullous disease of the elderly. Patients' auto-antibodies are directed against BP180, a transmembrane hemidesmosomal glycoprotein of basal keratinocytes. Between 1989 and 1998, we identified 115 patients with BP in the Department of Dermatology at the University of Würzburg. This is one of the largest groups of patients with BP studied to date. In all patients, direct and/or indirect immunofluorescence microscopy studies were positive. The average age (+/- standard deviation) of the patients was 75 +/- 12 years, the median was 78 years. The youngest patient was 39 years of age; the oldest, 99 years. 54% of the patients were female and 46% male. In 24% of the patients, an involvement of oral, and in 7% of genital mucous membranes was seen. 98% of the patients complained about pruritus. By direct immunofluorescence microscopy, linear deposits of C3 and/or IgG were detected at the basement membrane zone of perilesional skin biopsies. By indirect immunofluorescence microscopy using NaCl-separated human skin, 87% of cases revealed circulating serum antibodies whereas on monkey esophagus, only 72% of sera were found positive. In 85% of the patients, we detected elevated serum levels of total IgE before the initiation of treatment. In those sera that were analyzed for reactivity with BP180, autoantibodies to the immunodominant NC16 A domain of BP180 were detected in 89% by immunoblot analysis and in 93% by ELISA. Therefore, in most patients, BP can be diagnosed serologically.