No abstract

Dendritic cells (DCs) are potent antigen-presenting cells (APCs); they are considered to be the most important APC in the lung. Recently, the number of DCs in the large airways was demonstrated to increase in patients with atopic asthma, leading to the concept that DCs play an important role in airway inflammation. However, little is known about the distribution of lung DCs in the small airways under other pathological conditions. The aim of the present study was to examine the distribution of DCs in the bronchiolar tissues in patients with diffuse panbronchiolitis (DPB), which is a chronic inflammatory disorder of the airways histologically characterized by peribronchiolitis. We investigated the distribution of DCs in the bronchiolar tissues of the lungs in 11 patients with DPB and 7 control subjects with normal lungs using immunohistochemical methods. Marked increases in the number of CD1a(+), CD1c(+), and CD83(+) DCs were found in both the bronchiolar epithelium and submucosal tissues of patients with DPB, compared with control subjects with normal lungs. The most striking increase occurred in the number of DCs expressing CD83, a marker of mature DCs, in the submucosal tissues of patients with DPB. The increases of these positive cells in patients with DPB were more marked in the submucosal tissues than in the epithelium. The bronchiolar epithelial cells in patients with DPB strongly expressed GM-CSF protein, which is an important cytokine for the differentiation and function of DCs, suggesting that the increased local production of GM-CSF may be responsible for the accumulation and differentiation of DCs in the bronchiolar tissues of patients with DPB. These results suggest that increased DCs in the bronchiolar tissues, together with their phenotypical maturation, may play an important role in the mucosal immune response in patients with DPB through their potent antigen-presenting function.

The modified PSI could identify low-risk patients more accurately than the original PSI. In addition, by combining the modified PSI with PS, higher performance was obtained. Such information would aid physicians in clinical decision-making without overestimating the risk for elderly patients with CAP.

There is a considerable overlap between diffuse panbronchiolitis (DPB) and bronchiolar disease associated with rheumatoid arthritis.The present study assessed how these conditions could be differentiated.The subjects included 25 DPB patients and 15 RA patients with bronchiolar disease (RA-BD). Patients with either condition had chronic cough, purulent sputum, dyspnea and coarse crackles. Most patients with either DPB or RA-BD had a history of sinusitis as well as elevated cold hemagglutin titers and decreased levels in partial pressure of oxygen (PaO2), forced expiratory volume in one second (FEVX0) and V 25/Ht. On histological examination, both conditions also shared various histological patterns although panbronchiolitis lesions were more common in DPB than RA-BD (68% vs 20%) and bronchiolar obliteration appeared to occur at more proximal sites in RA-BD than DPB. However, there were important differences: long-term treatment with erythromycin had less effect in RA-BD than DPB, and the frequency of HLA B54 tended to be higher in DPB than RA-BD (50.0% vs 22.2%), suggesting that they are distinct conditions. (Internal Medicine 37: 504-508, 1998)