Detection of IL-1α, IL-1β and IL-1 receptor antagonist in blister fluid of bullous pemphigoid

Bullous pemphigoid (BP) is an autoimmune subepidermal blistering disease. In addition to autoantibodies, complement activation and inflammatory cells are necessary for lesion formation. In this study, we investigated the potential involvement of IL-1, secreted by various inflammatory and non-inflammatory cells, in BP lesions. We determined IL-1α IL-1β and IL-1 receptor antagonist in both blister fluid and concurrent serum samples of 10 BP patients by ELISAs. For comparison, we assayed experimentally generated suction blisters from 10 healthy volunteers. IL-1β levels were significantly elevated in BP blisters, whereas levels of IL-1α were decreased relative to those in controls. In concurrent serum samples, no IL-1α or IL-1β were detected in patients or controls. Levels of IL-1 receptor antagonist were significantly higher in BP blisters in relation to both concurrent sera and suction blisters. Our data indicate the release of IL-1β, IL-1 receptor antagonist, and to a lesser extent, of IL-1α, at the site of blister formation in BP and support the notion that cell-mediated immune mechanisms may contribute to blister formation in this disease.