Bullous pemphigoid (BP) has been suggested to be an autoimmune inflammatory disease affecting the cutaneous basement membrane zone (BMZ) [7]. Immunologic abnormalities include circulating complement-activating autoantibodies against BP antigen [6,12]. Current evidence suggests that the inflammatory is initiated and directed at the BMZ by antibody-mediated complement activation [8], and that dermoepidermal separation (DES) is due to BMZ injury by activated leukocytes, particularly eosinophilis or neutrophils [5,10,11,15].
Recent investigations on density gradient centrifugation of peripheral blood leukocytes have shown that eosinophils from eosinophilic patients are less dense than those from healthy subjects [4]. These hypodense eosinophils have higher functional and metabolic activities than normodense eosinophils, so that they are suggested to be in activated state [3,16]. In BP lesion, if eosinophils are in an activated state, they may become hypodense. The experiment described here was designed to determine whether BP blister fluids (BP-BF) have an effect on eosinophil density. Blister fluids were obtained from four patients with BP (Table 1) and a patient with pemphigus vulgaris, who were diagnosed on the basis of clinical and immunological findings, and from two patients with burn. Suction blisters from normal volunteers were induced using the method o.f Kiistala [9]. BP-BF were heat-inactivated at 56~ for 30 min (hiBP-BF), and dialyzed BP-BF (diBP-BF) were prepared by