A cohort study of mortality predictors and characteristics of patients with combined pulmonary fibrosis and emphysema

OBJECTIVES: Our purpose was to assess the clinical data, predictors of mortality and acute exacerbation (AE) in combined pulmonary fibrosis and emphysema (CPFE) patients. DESIGN: Single-centre retrospective cohort study. SETTING: Teaching hospital in Japan. PARTICIPANTS: We identified 93 CPFE patients with high-resolution computed tomographic (HRCT) through multidisciplinary discussion. Patients who had connective tissue disease, drug-associated interstitial lung disease and occupationally related interstitial lung disease, such as asbestosis and silicosis, were excluded. INTERVENTIONS: There were no interventions. METHODS: Medical records and HRCT scans from January 2002 through December 2007 were reviewed retrospectively at our hospital. Ninety-three patients had CPFE. RESULTS: The mean age of CPFE patients was 74 years. Idiopathic pulmonary fibrosis and non-specific interstitial pneumonia were observed as distinct HRCT patterns. Forty-two patients showed finger clubbing. Mean serum Krebs von den Lungen-6 (KL-6) and per cent predicted forced vital capacity (%FVC) were 1089 IU/l, 63.86%, respectively. Twenty-two patients developed AE during observation period. Baseline KL-6 was a strong predictor of AE (OR=1.0016, p=0.009). Finger clubbing (HR=2.2620, p=0.015) and per cent predicted forced expiratory volume in one second/%FVC more than 1.2 (HR=1.9259, p=0.048) were independent predictors of mortality in CPFE. CONCLUSIONS: Baseline serum KL-6 was a useful predictor of AE (cut-off =1050, receiver operator characteristic curve: 0.7720), which occurred in 24% (22/93) of the CPFE patients. Finger clubbing and per cent predicted forced expiratory volume in one second/%FVC more than 1.2 were independent predictors of mortality.