Combined pulmonary fibrosis and emphysema

Abstract

The purpose of this review is to provide an update on combined pulmonary fibrosis and emphysema (CPFE), with specific focus on the definition of CPFE and potential management options. There is no consensus regarding criteria for a diagnosis of CPFE, and multiple definitions of CPFE have been used in previous studies. Patients with CPFE have relatively preserved airflow and lung volume, with disproportionately impaired oxygenation. The risk of lung cancer and pulmonary hypertension is higher for CPFE than for idiopathic pulmonary fibrosis alone, but the effect of CPFE on overall mortality is unclear. There are no evidence-based recommendations for management of CPFE, and patients are currently managed according to individual guidelines for chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis. Further research is required to determine the biological mechanisms of CPFE, and to establish whether it is a distinct biological condition or a coincidental occurrence of two separate conditions. Key points  Previous studies have used multiple definitions of CPFE. A broad definition of CPFE that includes any type of interstitial lung disease and any amount of emphysema is not appropriate for all research questions.  Combined pulmonary fibrosis and emphysema (CPFE) is a distinct clinical phenotype that predominantly includes male smokers with pulmonary function tests characterized by relatively preserved flow rates and lung volumes, with markedly reduced carbon monoxide diffusion capacity.  Lung cancer and pulmonary hypertension seem to be more common in CPFE than in IPF, and these complications are associated with a particularly poor prognosis.  There are no evidence-based recommendations for the management of CPFE. In the absence of direct evidence, patients with CPFE are usually managed according to the principles that guide therapy for isolated chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis.  Future studies are required to determine the underlying biological mechanisms of CPFE and to establish whether CPFE is a biologically distinct condition or an overlap of two separate conditions that share similar risk factors.