Asymmetry in acute exacerbation of idiopathic pulmonary fibrosis.

Acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) results in poor survival. The objective of the present study was to elucidate the impact of asymmetrical ground-glass opacity (GGO) and/or consolidation on outcomes in patients with AE-IPF. The cases of 59 consecutive patients with AE-IPF were retrospectively reviewed. High-resolution computed tomography (HRCT) at diagnosis of an AE was assessed to determine the disease extent and asymmetry. Asymmetrical AE was defined as a right-to-left ratio of GGO and consolidation ≥2.0 or ≤0.5. The impacts of HRCT indices and other clinical parameters on 180-day mortality were analysed. The overall 180-day mortality rate was 59.2%, and asymmetrical AE was observed in 13 patients (22.0%). A multivariate analysis revealed that asymmetrical AE was a significant predictor of 180-day mortality (hazard ratio=0.36, p=0.047), long-term oxygen therapy before AE and serum lactate dehydrogenase levels. The 180-day mortality of patients with asymmetrical AE was significantly lower than that of patients with symmetrical AE (asymmetrical AE 30.8% versus symmetrical AE 68.2%, p=0.03). An asymmetrical distribution of GGO and/or consolidation is a predictor of survival in patients with AE-IPF.