びまん性汎細気管支炎患者肺局所における炎症細胞集積と関連諸因子の解析

Abstract

Diffuse panbronchiolitis (DPB) is characterized by a dense neutrophil infiltration in association with the high level of interleukin 8 (IL-8) in the airway and an accumulation of lymphocytes, especially CD8+HLA-DR+cells. In this study, we demonstrated that IL-8 mRNA was expressed in alveolar macrophages in the air space, bronchiolar epithelial cells and endothelial cells by in situ hybridization method, while not in foamy macrophages in the interstitium. A two-color analysis of T cell subsets in bronchoalveolar lavage (BAL) fluid also revealed a significant increase in the number of CD8+CD11b- cytotoxic T cells and CD4+CD29+ memory T cells and the mean fluorescence intensity of CD49d (very late antigen, VLA-4α) on CD4+cells in the patients. Furthermore, the level of RANTES and MIP-1α in DPB patients was significantly higher than that in healthy volunteers, and there was a trend toward a correlation between RANTES concentration and the absolute number of memory T cells in BAL fluid (r=0.731, p=0.188) .Our results suggest that elevation of memory T cells and cytotoxic T cells, in addition to neutrophils, in the airway lumen of DPB patients may contribute to chronic bronchial inflammation, possibly through up-regulation of adhesion molecule, VLA-4 and chemokines produced in the lung.