Combined pulmonary fibrosis and emphysema in systemic sclerosis: A syndrome associated with heavy morbidity and mortality

Abstract

Background: The syndrome of combined pulmonary fibrosis and emphysema (CPFE) primarily due to tobacco smoking has been reported in connective tissue disease, but little is known about its characteristics in systemic sclerosis (SSc).

Methods: In this retrospective multi-center case-control study, we identified 36 SSc patients with CPFE, and compared them with 72 SSc controls with interstitial lung disease (ILD) without emphysema.

Results: Rate of CPFE in SSc patients with CT scan was 3.6%, and 7.6% among SSc patients with ILD. CPFE-SSc patients were more likely to be male (75 % vs 18%, p < 0.0001), smokers (83 % vs 33%, p < 0.0001), and to have limited cutaneous SSc (53 % vs 24% p < 0.01) than ILD-SSc controls. No specific autoantibody was significantly associated with CPFE. At diagnosis, CPFE-SSc patients had a greater decrease in carbon monoxide diffusing capacity (DLCO 39 ± 13 % vs 51 ± 12% of predicted value, p < 0.0001) when compared to SSc-ILD controls, whereas lung volumes (total lung capacity and forced vital capacity) were similar. During follow-up, CPFE-SSc patients more frequently developed precapillary pulmonary hypertension (PH) (44 % vs 11%, p < 10^-4), experienced more frequent unscheduled hospitalizations (50 % vs 25%, p < 0.01), and had decreased survival (p < 0.02 by Kaplan-Meier survival analysis) as compared to ILD-SSc controls.

Conclusions: The CPFE syndrome is a distinct pulmonary manifestation in SSc, with higher morbidity and mortality. Early diagnosis of CPFE by chest CT in SSc patients (especially smokers) may result in earlier smoking cessation, screening for PH, and appropriate management.

Keywords: Combined pulmonary fibrosis and emphysema; Prognosis; Pulmonary hypertension; Survival; Systemic sclerosis.