A 67-year-old never-smoker was diagnosed with diffuse panbronchiolitis (DPB) and was started on 250 mg azithromycin twice weekly. Over a 16-month observation period, lung function was assessed monthly, including a dedicated small airways test, the multiple breath nitrogen washout (MBW) with indices S-cond and S-acin of ventilation heterogeneity at the level of the conductive and acinar air spaces, respectively. Baseline measurements indicated moderate airway obstruction, air trapping and considerable dysfunction of the small airways around the acinar entrance. Treatment resulted in excellent symptomatic improvement paralleled by marked improvements in FEV1, FVC, RV/TLC, S-cond and S-acin; by contrast, there were no consistent changes in FEF75 or TLCO. While improvements were such that S-cond fell within normal limits after 5 months, S-acin remained abnormal even after 16 months of treatment. This suggests a distinct acinar structural abnormality in DPB that cannot be reversed by azithromycin.
|Status||Published - 2012|