Abstract
The granules of the eosinophil contain a variety of hydrolytic enzymes, including arylsulfatase A and B. Arylsulfatase activity is known to correlate well with eosinophil levels, and eosinophil arylsulfatase B was found to inactivate ECF-A and SRS-A. Bullous pemphigoid is a chronic cutaneous disease characterized by subepidermal bullae and perivascular accumulation of eosinophils, although the pathomechanisms of the development remain obscure. In the present study, arylsulfatase activity in the blister fluid was investigated to elucidate the role of eosinophils in cases of bullous pemphigoid. Nine patients with bullous pemphigoid were diagnosed using immunological approaches. Bullous fluid was aseptically aspirated and stored at -70°C until use. Blisters in four patients with burns served as the controls. The activity of arylsulfatase was estimated by the amount of 4-nitrocatechol liberated in μg/ml/hr of blister. The increased activity of arylsulfatase was observed in the blister fluid of bullous pemphigoid (A: 6.552±1.083μg/ml/hr, B: 25.797±7.052μg/ml/hr), as compared with findings in the controles (A: 3.118±0.224μg/ml/hr, B: 3.447±0.508μg/ml/hr). The activity of arylsulfatase was remarkably reduced after treatment with prednisolone in two cases. These reductions also correlated well with the levels of peripheral blood eosinophilia and the concentration of IgE in the sera. Demonstration of arylsulfatase in the tissue fluid suggests that hydrolytic enzyme may play a pathogenic role during the initial stage of blister formation in cases of bullous pemphigoid.
