High Levels of Soluble CD23 in Blister Fluid of Patients With Bullous Pemphigoid

Abstract

Bullous pemphigoid (BP) is an autoimmune subepidermal blistering skin disease in which autoantibodies are directed against hemidesmosomal proteins of basal keratinocytes. In serum samples of patients with BP, elevated levels of total IgE are a common finding, and, recently, cells expressing the low-affinity receptor for IgE (FceRII/CD23) have been found in the dermal infiltrate of BP lesions. 1 In this study, we were interested in levels of soluble CD23, which may be shed from the CD23-bearing cells, and concentrations of total IgE in blister fluid from patients with BP. Subjects and Methods. Before initiation of treatment, 10 patients with typical clinical, histologic, and direct immunofluorescent features of BP were studied. Indirect immunofluorescence on 1-mmol/L sodium chlorideseparated human skin demonstrated circulating IgG antibodies binding exclusively to the epidermal side of the split. Titers ranged from 1:10 to 1:1280. In one patient, no circulating antibodies were detected. As a control, suction blisters