Diffuse panbronchiolitis and rheumatoid arthritis-associated bronchiolar disease: similarities and differences.

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 (FEV1.0) 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.