Diffuse panbronchiolitis (DPB) is a rare chronic inflammatory obstructive pulmonary disease primarily affecting the respiratory bronchioles. 'Diffuse' refers to the distribution of the lesions throughout both lungs, and 'pan-' refers to the involvement of inflammation in all layers ... Diffuse panbronchiolitis (DPB) is a rare chronic inflammatory obstructive pulmonary disease primarily affecting the respiratory bronchioles. 'Diffuse' refers to the distribution of the lesions throughout both lungs, and 'pan-' refers to the involvement of inflammation in all layers of the respiratory bronchioles. Onset of the disorder occurs in the second to fifth decade of life, and is clinically manifest by chronic cough, exertional dyspnea, and sputum production. Most patients also have chronic paranasal sinusitis. If untreated, the disorder progresses to bronchiectasis, respiratory failure, and death (summary by Poletti et al., 2006).
Yamanaka et al. (1969) first described a chronic airway disease in Japan. They termed it diffuse panbronchiolitis to distinguish it from chronic bronchitis.
Homma et al. (1983) reported numerous Japanese patients with diffuse panbronchiolitis. Patients with ... Yamanaka et al. (1969) first described a chronic airway disease in Japan. They termed it diffuse panbronchiolitis to distinguish it from chronic bronchitis. Homma et al. (1983) reported numerous Japanese patients with diffuse panbronchiolitis. Patients with the disease had obstructive respiratory impairment, similar to emphysema, with occasional wheezing and coughing, similar to bronchial asthma. There was often sputum production, resembling chronic bronchitis. In the advanced stages of the disease, there was a large amount of purulent sputum and dilatation of proximal terminal conducting bronchioli, resembling bronchiectasis. Pathologic findings included chronic inflammation, with interstitial infiltration of lymphocytes, plasma cells, and histiocytes, exclusively located in the respiratory bronchioles and associated with thickening of the wall of the respiratory bronchiole. Some had extension of the inflammatory changes toward peribronchiolar tissues. Secondary ectasia of proximal bronchioli occurred in advanced stages. Homma et al. (1983) suggested that diffuse panbronchiolitis belongs to a distinct disease category and should be distinguished from more common diseases, because it often shows rapid progression with fatal outcome. The disease occurred more frequently in males, and onset was unrelated to age. More than 1,000 cases of probable diffuse panbronchiolitis and 82 histologically-confirmed cases had been collected in Japan. Kim et al. (1992) reported 5 Korean unrelated patients, including 2 women, with diffuse panbronchiolitis. Two were histologically proven, and 3 were suspected based on clinical symptoms and radiographic studies. All 5 had the typical respiratory symptoms and signs, including onset in their twenties of progressive wheezing, dyspnea, cough, and sputum production associated with crackles and rhonchi on auscultation. All patients also had a history of chronic sinusitis, and none had a history of smoking. High-resolution CT scan showed hyperinflated lungs with diffuse small nodular densities, 2 to 3 mm in diameter, and thickened bronchial walls, especially in the lower lung fields. Lung biopsies of 2 patients showed thickening of the wall of the bronchioles with infiltration of lymphocytes, plasma cells, and foamy histiocytes, which were also present in adjacent alveolar septa. All patients showed clinical improvement with low-dose erythromycin. Chu et al. (1992) reported a 33-year-old Chinese man who presented with a productive cough of yellowish sputum for several years, and progressive dyspnea on exertion that had been present for 1 year. Physical examination showed clubbing of the fingers and diffuse inspiratory crackles and some rhonchi on auscultation. Plain chest film showed diffuse fine nodular lesions in both lungs, and pulmonary function tests demonstrated obstructive ventilatory impairment. CT scan of the chest showed diffuse fine nodular infiltrations in both lung fields. Arterial blood gas analysis showed mild hypoxemia. Open lung biopsy specimen showed features of diffuse panbronchiolitis. Tsang et al. (1998) reported 7 additional Chinese patients who fulfilled the clinical criteria for DPB, including 3 women. All 7 patients were never smokers.
Diffuse panbronchiolitis predominantly affects East Asians, occurring with a frequency of 11 per 100,000 in the Japanese population (Homma et al., 1983). The disease has also been reported in Korea (Kim et al., 1992) and China (Chu et ... Diffuse panbronchiolitis predominantly affects East Asians, occurring with a frequency of 11 per 100,000 in the Japanese population (Homma et al., 1983). The disease has also been reported in Korea (Kim et al., 1992) and China (Chu et al., 1992; Tsang et al., 1998). A few cases have been reported outside Asia, notably in Asian emigrants (Hoiby, 1994; Corne, 1996).