Introduction: Combined pulmonary fibrosis and emphysema (CPFE) patients exhibit distinct clinical features and worse outcomes compared to pulmonary fibrosis patients. However, there is a lack of quality research comparing CPFE and emphysema alone.

Objectives: To assess for clinical and radiologic differences between CPFE and emphysema alone.

Methods: An observational cohort including patients with CPFE or emphysema from a tertiary medical center. The two groups were matched by sex, pack years (PYs) of smoking, and age. The emphysema features and CPFE diagnosis based on chest CT scans were classified by a chest radiologist according to the 2022 ATS/ERS/JRS/ALAT task force research definitions.

Results: 30 CPFE 30 and matched emphysema patients were included. In each group 73.3% were males, the average PYs was 37, and age was 67.5 years. Patients with CPFE had a higher body mass index (BMI), less obstructive spirometry, and lower TLC and RV (Table). Only one patient (3%) with CPFE had extensive emphysema (>30% of lung fields) compared with 10 (33%) in the emphysema group (P=0.003). Both groups showed an upper lobe predominance of emphysema distribution (86.4%, P=0.6) and no significant difference in emphysema pattern between paraseptal, centrilobular, mixed or other pattern (P=0.2).

Conclusion: After adjusting for the major baseline characteristics, CPFE was associated with less extensive emphysema, higher BMI, less obstructive spirometry, and lower lung volumes compared to emphysema alone.