OBJECTIVETo summarize the clinical features of diffuse panbronchiolitis (DPB).

METHODWe retrospectively analyzed the clinical data of 35 patients who had been admitted to Peking Union Medical College Hospital from December 1996 to July 2014 due to DPB,which was confirmed basing on the diagnostic criteria proposed in 1998 by a working group of the Ministry of Health and Welfare of Japan or histopathological examination.

RESULTSThe average age of these 35 patients (20 men and 15 women,with a sex ratio of 1.33 to 1) was (42.2<15.6) years,mainly distributed in the 40-49 age group. The average clinical history was (8.4<8.5) years. The main symptoms and signs of DPB included chronic cough (n=35,100%),copious purulent sputum production (n=31,88.6%),exertional dyspnoea (n=24,68.6%),end-inspiratory crackles (n=28,80.0%). Also,26 patients (74.3%) had a history of sinusitis. Cold agglutination test in 15 out of 15 patients were negative. Pseudomonas aeruginosa and Haemophilus influenza were isolated from 22 patients (73.3%,22/30),and 26 patients (83.9%,26/31) had hypoxemia. The mean values of forced expiratory volume in the first second/forced vital capacity,residua volume/total lung volume,maximum forced expiratory volume of 50% lung volume,and maximum forced expiratory volume of 25% lung volume were 60.5%,53.8%,25.9%,and 31.2%,respectively. The most common CT findings from this cohort of patients were bronchiectasis and bronchiolitis,with nodular shadows distributed in a centrilobular pattern. Finally,29 patients were misdiagnosed as other conditions such as pulmonary infection and bronchiectasis.

CONCLUSIONSDPB in Chinese populations have different presentations compared to that Japanese populations:for instance,the serum cold agglutination test always shows negative results,which is often inconsistent with the pathogens in sputum. DPB usually is misdiagnosed. Clinicians should take DPB into consideration when patients had pulmonary infection and sinusitis.