Acute exacerbation of idiopathic pulmonary fibrosis: a clinical review

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive fibrotic disease limited to the lung, with high variability in the course of disease from one patient to another. Patients with IPF may experience acute respiratory deteriorations; many of these acute declines are idiopathic and are termed acute exacerbations (AE) of IPF. In these cases, the exclusion of alternative causes of rapid deterioration, including heart failure, bilateral pneumonia or pulmonary embolism, is a challenging goal. AE may occur at any time during the course of IPF, although they are more common in patients with more progressive disease and gastroesophageal reflux. Surgical lung biopsy or even surgical procedures in organs other than the lungs may also trigger AE, mainly in rapidly progressive or advanced IPF. Current diagnostic criteria include the presence of new-onset ground glass opacities or airspace consolidation superimposed on an underlying usual interstitial pneumonia pattern seen on high-resolution computed tomography. The outcome is poor with a short-term mortality in excess of 50% despite therapy. Currently, there is no treatment with demonstrated efficacy for AE-IPF: empirical high-dose corticosteroid therapy is generally used, with or without immunosuppressive agents, with limited evidence. On the other hand, there is hope that new treatments to slow down progression of IPF will translate into a reduction of AE-IPF's occurrence. In conclusion, although significant progress in assessing disease severity in IPF has been made, AEs remain unpredictable and are associated with a high risk of death. Improvements in our understanding of the etiology, risk factors, clinical predictors and epidemiology are needed. It is the goal of clinical researchers in the field to provide respiratory physicians with evidence-based guidance to identify patients who may benefit from therapy for preventing or treating AE-IPF.