Distinct Characteristics of Pleuroparenchymal Fibroelastosis With Usual Interstitial Pneumonia Compared With Idiopathic Pulmonary Fibrosis

BACKGROUND: Pleuroparenchymal fibroelastosis (PPFE) is a rare form of interstitial pneumonia and sometimes coexists with a histologic usual interstitial pneumonia (UIP) pattern. This study aimed to describe the distinct clinical features of PPFE with UIP pattern compared with idiopathic pulmonary fibrosis (IPF). METHODS: We conducted a retrospective review of the medical records of 110 consecutive patients with IPF with a histologic UIP pattern on surgical lung biopsy specimen. Patients meeting radiologic criteria for the diagnosis of PPFE based on high-resolution CT scan and with a histologic UIP pattern were included. RESULTS: Nine of eleven patients meeting radiologic criteria for the diagnosis of PPFE were histologically confirmed as having PPFE with UIP pattern. The PPFE with UIP pattern group showed a significantly higher residual volume (1.8 L vs 1.3 L, P<.01), higher Paco(2) (44.6 mm Hg vs 41.7 mm Hg, P = .04), and higher complication rate of pneumothorax and pneumomediastinum than the 99 patients with IPF/UIP. The ratio of anteroposterior to transthoracic diameter in patients with PPFE with UIP pattern was significantly lower than that in patients with IPF/UIP (P = .04). Survival time tended to be shorter in patients with PPFE with UIP pattern. CONCLUSIONS: The results support the view that PPFE with UIP pattern is a disease entity distinct from IPF/UIP and may well be classified as PPFE.