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

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. 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). 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 < 0.0001), and the most common cause of death was chronic respiratory failure (73.8%), followed by AE (14.3%). Male gender was the only poor prognostic factor of iPPFE. The present study demonstrated efficiency of clinical diagnosis and also revealed clinically important characteristics of iPPFE that should be considered for management of iPPFE.

Suzuki Y ，Fujisawa T ，Sumikawa H ，Tanaka T ，Sugimoto C ，Kono M ，Hozumi H ，Karayama M ，Furuhashi K ，Enomoto N ，Nakamura Y ，Inui N ，Suda T ... -  《-》

Clinical significance of lower-lobe interstitial lung disease on high-resolution computed tomography in patients with idiopathic pleuroparenchymal fibroelastosis.

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare form of idiopathic interstitial pneumonias (IIP) and may have other patterns of interstitial lung disease (ILD) in the lower lobe, such as usual interstitial pneumonia (UIP). However, the clinical significance of lower-lobe ILD in patients with IPPFE is unclear. A retrospective review of 40 consecutive patients with clinically diagnosed IPPFE in our institution from 2005 to 2016 was conducted. The presence of lower-lobe ILD on high-resolution computed tomography (HRCT) was assessed and classified into UIP or non-UIP pattern according to a modification of diagnostic criteria for idiopathic pulmonary fibrosis. Clinical characteristics and prognostic factors were evaluated. Among the 40 patients with IPPFE, 21 (53%) had lower-lobe ILD, including 13 with UIP pattern and 8 with non-UIP pattern. Patients with IPPFE who had lower-lobe ILD had significantly older age, higher frequency of fine crackles, higher serum KL-6 level, lower residual volume (RV), and lower total lung capacity (TLC) than those without lower-lobe ILD. In addition, those with lower-lobe ILD, especially UIP pattern, had a significantly poorer survival than those without lower-lobe ILD (log-rank test; p = 0.014, p < 0.001, respectively). Multivariate Cox proportional hazards regression analysis revealed that low %forced vital capacity (%FVC) at baseline and coexistence of UIP pattern were significantly associated with poor prognosis in patients with IPPFE. The coexistence of lower-lobe ILD on HRCT, especially the UIP pattern, may predict poor survival in patients with IPPFE.

Kono M ，Fujita Y ，Takeda K ，Miyashita K ，Tsutsumi A ，Kobayashi T ，Miki Y ，Hashimoto D ，Enomoto N ，Nakamura Y ，Suda T ，Nakamura H ... -  《-》

The pathogenesis and pathology of idiopathic pleuroparenchymal fibroelastosis.

Kinoshita Y ，Ishii H ，Nabeshima K ，Watanabe K ... -  《-》

Quantitative analysis of lung elastic fibers in idiopathic pleuroparenchymal fibroelastosis (IPPFE): comparison of clinical, radiological, and pathological findings with those of idiopathic pulmonary fibrosis (IPF).

Enomoto N ，Kusagaya H ，Oyama Y ，Kono M ，Kaida Y ，Kuroishi S ，Hashimoto D ，Fujisawa T ，Yokomura K ，Inui N ，Nakamura Y ，Suda T ... -  《BMC Pulmonary Medicine》

Usual Interstitial Pneumonia Pattern in the Lower Lung Lobes as a Prognostic Factor in Idiopathic Pleuroparenchymal Fibroelastosis.

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a rare interstitial pneumonia that is characterized by stiffness in both the upper lobes and pleura, which is evident on high resolution computed tomography (HRCT) of the chest. However, prognostic factors for IPPFE have not been identified yet. We aimed to investigate the clinical prognostic factors affecting survival in patients with IPPFE. Between April 2009 and September 2017, we enrolled 36 patients who were clinically diagnosed with IPPFE, using HRCT. These patients were classified as either short survival (dead within 12 months from the diagnosis of IPPFE) or long survival (survived for greater than 12 months) groups. We retrospectively analyzed the clinical characteristics, serum markers, pulmonary function test results, and HRCT findings. Twelve patients were classified into the short survival and 24 were categorized into long survival categories. At the time of diagnosis, the incidence of coexistence of a usual interstitial pneumonia (UIP) pattern in the lower lobes on HRCT in the short survival was significantly higher than that in the long survival. Multivariate analysis revealed that a UIP pattern in the lower lobes on HRCT was the only independent variable for poor prognosis. The median survival time from diagnosis in patients with IPPFE was 24 months. Of these patients with IPPFE, the survival time with a UIP pattern was significantly shorter than in those without a UIP pattern. Our findings suggest that a UIP pattern in the lower lobes at the time of diagnosis was an independent prognostic factor for IPPFE.

Kato M ，Sasaki S ，Kurokawa K ，Nakamura T ，Yamada T ，Sasano H ，Arano N ，Komura M ，Ihara H ，Nagashima O ，Shiota S ，Takahashi F ，Takahashi K ... -  《-》