Progression of idiopathic pulmonary fibrosis: lessons from asymmetrical disease

BackgroundIn idiopathic pulmonary fibrosis (IPF) the distribution and spatial-temporal progression of fibrotic changes may be influenced by general or locoregional conditions. From this perspective, patients with asymmetrical disease (AIPF) may be unique.MethodsThis retrospective study included 32 patients (26 men, mean±SD age 69±7 years) with AIPF, as defined by an asymmetry ratio (most affected – least affected fibrosis score)/(most affected + least affected fibrosis score) >0.2. The global fibrosis score was the average of the right and left scores. Patients with AIPF were compared with 64 matched controls with symmetrical IPF.ResultsPatients with AIPF did not differ from controls in global fibrosis score and forced vital capacity, but carbon monoxide transfer factor was less decreased (52±19% vs 43±13%, p=0.009). The rate of gastro-oesophageal reflux and acute exacerbations was significantly higher in patients with AIPF (62.5% vs 31.3%, p=0.006 and 46.9% vs 17.2%, p=0.004, respectively). In patients with AIPF the right side was more likely to be involved (62.5%); the median asymmetry ratio was 0.5 (range 0.24–1). Although the global fibrosis score worsened significantly in all 23 patients with AIPF with serial high-resolution CT scans (p