Combined Pulmonary Fibrosis and Emphysema: A Distinct Phenotype of Smoking-Related Lung Disease

Abstract

INTRODUCTION: Combined pulmonary fibrosis and emphysema (CPFE) is a syndrome that is characterised by centrilobular and/or paraseptal emphysemas in upper lung zones associated with pulmonary fibrosis in lower lobes. In this retrospective cohort study: demographics, clinical and radiological characteristics and pulmonary function tests of patients with CPFE were reviewed. Patient survival were also analysed. Medical records and high resolution computed tomographic (HRCT) images of 10 patients with CPFE were reviewed through multidisciplinary discussion including pulmonologists and a radiologist. Survival was calculated from date of first assessment to the date of death, or from date of first assessment to the date of review. CASE PRESENTATION: The mean age is 65 years, and all of the patients are male. All patients had histories of smoking (mean: 41 pack-years). One patient had 30 pack year history of smoking associated with the occupational exposure of lead and sulfur gas during 8 years. Mean FVC, FEV1, FEV1/FVC and DLCO were 64%, 66%, 81%, and %30, respectively. The HRCT images showed that, 9 patients had paraseptal emphysema and bullous formation, 5 had centrilobular emphysema, 8 had honeycombing, 10 had reticulation, traction bronchiectasis, and ground-glass opacity, 6 had bronchial distortion. The mean diameter of the main pulmonary artery was 32.6 mm. In one case, a new nodular lesion of 1.2 cm, which is not exist a year ago, was found Eight patients required supplemental oxygen therapy during their follow-up, and 2 patients died. Two patients developed pneumothorax and pleuredesis was performed in one of them because of recurrent pneumothorax. Deep venous thrombosis occured in a patient. The median survival of this cohort is 3.6 years. DISCUSSION: The CPFE syndrome typically occurs in current or ex-smoker male gender. The subset of patients (predominantly male) exposed to cigarette smoking may be vulnerable to developing the typically extensive emphysema and pulmonary fibrosis. The physiologic outcomes of CPFE syndrome include normal or subnormal expiratory flow rates and lung volumes in the setting of extensive radiologic evidence and severely impaired DLCO. Patients with CPFE have a high prevalences of pulmonary hypertansion and lung cancer. The main pulmonary artery diameter of 29 mm or larger on computed tomography scan has a sensitivity of 69% and a specificity of 100% for predicting pulmonary hypertension. In this cohort, main pulmonary artery diameter is greater than 29 mm in all patients. This suggests increased pressures in the pulmonary system of all patients. CONCLUSIONS: Characteristic epidemiologic, clinical and radiologic findings in the CPFE syndrome include smoking history, male predominance, hypoxemia, normal or subnormal sprometric values despite extensive radiologic involvement, and marked impairement of gas exchange. In patients with dyspnea, an isolated reduction in DLCO is extremely rare and one of the causes is CPFE.