Effects of suplatast tosilate on allergic eosinophilic airway inflammation in patients with mild asthma.

Abstract

Bronchial asthma is a chronic inflammatory disease characterized mainly by infiltration of the airway mucosa by various inflammatory cells, notably eosinophils. T(H)2-type cytokines are suggested to be deeply involved in the pathogenesis of asthma. We sought to determine the suppressive effects of suplatast tosilate, an inhibitor of T(H)2-type cytokines, on eosinophilic inflammation of the bronchial mucosa in patients with mild asthma. Airway hyperresponsiveness tests, pulmonary function tests, eosinophil measurements in induced sputum, and bronchial mucosa biopsies were performed before and after treatment with suplatast tosilate for 6 weeks in 15 patients with mild asthma and in 13 control patients with mild asthma not receiving suplatast tosilate. This study was performed as a case-controlled open study. In the treatment group a significant improvement in the provocation concentration of histamine was observed (P <.05). Improvements in peak expiratory flow (P <.01) and in symptom score (P <.05) were also noted in the suplatast tosilate-treated group. Moreover, the average number of infiltrating eosinophils and EG2(+) cells significantly decreased (both P <.05), as did the ratios of eosinophils and EG2(+) cells in sputum (both P <.01). The average number of CD4(+) and CD25(+) T lymphocytes also decreased (both P <.05). Suplatast tosilate appears to inhibit allergic airway inflammation mediated by T(H)2-type cytokine and to improve clinical symptoms in patients with mild asthma.