O7.11 Combined Pulmonary Fibrosis and Emphysema

Combined Pulmonary Fibrosis and Emphysema (CPFE) is suspected based on the presence of upper zone emphysema and lower zone fibrosis. Spirometry is frequently normal due to opposing effects of hyperinflation from emphysema and restriction from fibrosis. Gas transfer however, is usually severely impaired due to the additive effect of dual pathology (Jankowich 2012, Papaioannou 2016).  Cigarette smoking is a major risk factor. CPFE occurs predominantly in males (up to 9:1 male:female ratio). In non-smokers, CPFE has been described in people with occupational dust exposure and genetic mutations (Jankowich 2012, Papaioannou 2016).

CPFE has a higher mortality than that of emphysema alone. Prognosis has been shown to follow the course of patients with idiopathic pulmonary fibrosis (IPF) i.e. median survival between 2.1 and 8.5 years, or 5-year survival between 38% and 55% (Cottin 2017, Jankowich 2012, Papaioannou 2016). Even in patients who do not fulfil criteria for IPF, the presence of interstitial features in addition to emphysema carries a significantly higher mortality (Ash 2018).

In most cases, high resolution computed tomography (HRCT), spirometry and diffusing capacity of lung for carbon monoxide (DLCO) test are adequate to diagnose CPFE.  The prevalence of lung cancer is higher in CPFE than COPD.  Therefore more vigilant follow up of pulmonary nodules is recommended, though no specific screening guideline has been developed for CPFE (Jankowich 2012, Papaioannou 2016).

Currently, no specific treatment exists for CPFE.  Post-hoc data from nintedanib trials (INPULSIS (Richeldi 2014) and INPULSIS-ON (Crestani 2019), which included patients with concurrent emphysema, showed attenuation of rate of decline in forced vital capacity (FVC) in IPF with emphysema, similar to IPF without emphysema. An observational cohort study of real-world patients who were commenced on pirfenidone also showed similar rate of progression between CPFE and IPF without emphysema (Oltmanns 2014). Hence, antifibrotic therapy can be considered in CPFE, where presence of IPF is confirmed. Early referral for lung transplantation should be considered in patients with rapidly declining lung function.