Disease course and prognosis of pleuroparenchymal fibroelastosis compared with idiopathic pulmonary fibrosis

Abstract Background Idiopathic pleuroparenchymal fibroelastosis (iPPFE) is a rare interstitial lung disease characterized by unique radiological and pathological findings. However, pathological evaluations are available only in a limited number of patients. Therefore, several clinical diagnostic criteria have been proposed. Nevertheless, the applicability of these criteria has not yet been validated. Moreover, the clinical course of iPPFE and its prognosis have not yet been completely elucidated. Methods The present study assessed previously proposed clinical diagnostic criteria by comparing the clinical features between pathologically diagnosed iPPFE (p-iPPFE) and clinically diagnosed iPPFE (c-iPPFE). Subsequently, the clinical features of iPPFE were characterized and compared with those of idiopathic pulmonary fibrosis (IPF, n = 323). Results Clinical characteristics of c-iPPFE (n = 27) and p-iPPFE (n = 35) were similar. No significant difference was observed in terms of prognosis between c-iPPFE and p-iPPFE. The number of patients with iPPFE (both c-iPPFE and p-iPPFE) who developed lung cancer was significantly lower than that of patients with IPF. However, acute exacerbation (AE) showed similar incidence in patients with iPPFE and IPF. Survival of patients with iPPFE was significantly worse than that of patients with IPF (5-year survival rate: 38.5% vs. 63.5%, p  Conclusion The present study demonstrated efficiency of clinical diagnosis and also revealed clinically important characteristics of iPPFE that should be considered for management of iPPFE.