BACKGROUND:Although COPD and IPF are two different diseases, they can be seen together in the same patient group with smoking and advanced age. The definition of "Combined pulmonary fibrosis and emphysema" (CPFE) terminology was used in patients with both emphysema in the upper lung areas and radiological findings of IPF, as it may have a different clinical course. In our study, we aimed to compare emphysematous COPD patients with and without CPFE.
METHODS: A radiological appearance compatible with emphysema was detected in 104 of 183 COPD patients with CT, who were retrospectively screened. Thoracic CT scans were examined by a radiologist about lung involvement of IPF. COPD patients having emphysema fenotype were compared in terms of clinical, radiological features and respiratory reserve according to the presence of CPFE.

RESULTS: UIP pattern (11 definite, 4 probable UIP) was detected in 15 (14.4%) of 104 patients with emphysema. There was no significant difference between two groups (having CPFE or not) in terms of mean age, mMRC, CAT, and FVC values. The mean FEV1 value in patients with CPFE (FEV1: 1.82 lt - 72.1%) was found to be significantly higher than in patients with only emphysema (FEV1: 1.37 lt - 51.7%) (p<0.001 and p=0.006, respectively). The mean DLCO value was lower in CPFE patients (56.3% vs. 64.7%, p=0.104). 

CONCLUSIONS: The presence of CPFE has been detected at a high rate in emphysema patients. Therefore, when examining thorax CT images in COPD patients followed up for emphysema, evaluation for CPFE will be meaningful. Presence of lower DLCO value than expected in emphysematous COPD patients may be a sign for the development of UIP for the clinicians.