Radiological pleuroparenchymal fibroelastosis-like lesion in idiopathic interstitial pneumonias

Tomoyuki Fujisawa,Hiromitsu Sumikawa,Naoki Inui,Yuzo Suzuki,Kazuki Furuhashi,Takafumi Suda,Hironao Hozumi,Yasuoki Horiike,Shoichiro Matsushita,Ryoko Egashira,Masato Karayama,Hiroaki Sugiura,Kensuke Kataoka,Yutaro Nakamura,Hideki Yasui,Noriyuki Enomoto,Tae Iwasawa,Mikiko Hashisako

doi:10.1186/s12931-021-01892-9

Abstract

BackgroundPleuroparenchymal fibroelastosis (PPFE) is characterised by predominant upper lobe pleural and subpleural lung parenchymal fibrosis. Radiological PPFE-like lesion has been associated with various types of interstitial lung diseases. However, the prevalence and clinical significance of radiological PPFE-like lesion in patients with idiopathic interstitial pneumonias (IIPs) are not fully understood. We aimed to determine the prevalence and clinical impact on survival of radiological PPFE-like lesion in patients with IIPs.MethodsA post-hoc analysis was conducted using data from the Japanese nationwide cloud-based database of patients with IIPs. All the patients in the database were diagnosed as having IIPs by multidisciplinary discussion. Patients diagnosed with idiopathic PPFE were excluded. Clinical data and chest computed tomography (CT) image of 419 patients with IIPs were analysed. The presence of radiological PPFE-like lesion was independently evaluated by two chest radiologists blind to the clinical data.ResultsOf the 419 patients with IIPs, radiological PPFE-like lesions were detected in 101 (24.1%) patients, mainly in idiopathic pulmonary fibrosis (IPF) and unclassifiable IIPs, but less in idiopathic nonspecific interstitial pneumonia. Prognostic analyses revealed that radiological PPFE-like lesion was significantly associated with poor outcome in patients with IIPs, which was independent of age, IPF diagnosis and %FVC. In survival analyses, the patients with radiological PPFE-like lesions had poor survival compared with those without (log-rank, p < 0.0001). Subgroup analyses demonstrated that radiological PPFE-like lesion was significantly associated with poor survival both in patients with IPF and those with unclassifiable IIPs.ConclusionRadiological PPFE-like lesion is a condition that could exist in IIPs, mainly in IPF and unclassifiable IIPs. Importantly, the radiological PPFE-like lesion is a non-invasive marker to predict poor outcome in patients with IIPs, which should be carefully considered in clinical practice.

Highlights

Pleuroparenchymal fibroelastosis (PPFE) is characterised by predominant upper lobe pleural and subpleural lung parenchymal fibrosis
Idiopathic pleuroparenchymal fibroelastosis is a condition of idiopathic interstitial pneumonias (IIPs) characterised by fibrosis of the pleura and subpleural lung parenchyma accompanied by elastosis of Fujisawa et al Respiratory Research (2021) 22:290 the alveolar walls, predominantly in the upper lobe [1, 2]. iPPFE was categorised as a rare IIPs in the current classification of the American Thoracic Society (ATS)/ European Respiratory Society (ERS) Guidelines [3]
Patients with interstitial pneumonia (iNSIP) had less radiological PPFElike lesion, with radiological PPFE-like lesion detected in only three patients with iNSIP

Summary

Introduction

Pleuroparenchymal fibroelastosis (PPFE) is characterised by predominant upper lobe pleural and subpleural lung parenchymal fibrosis. The prevalence and clinical significance of radiological PPFE-like lesion in patients with idiopathic interstitial pneumonias (IIPs) are not fully understood. We aimed to determine the prevalence and clinical impact on survival of radiological PPFE-like lesion in patients with IIPs. Idiopathic pleuroparenchymal fibroelastosis (iPPFE) is a condition of idiopathic interstitial pneumonias (IIPs) characterised by fibrosis of the pleura and subpleural lung parenchyma accompanied by elastosis of Fujisawa et al Respiratory Research (2021) 22:290 the alveolar walls, predominantly in the upper lobe [1, 2]. Radiological PPFE-like lesion on high-resolution computed tomography (HRCT) has been reported in association with several forms of ILDs, including idiopathic pulmonary fibrosis (IPF), hypersensitivity pneumonitis and CTD-related interstitial lung disease (ILD) [7,8,9,10,11], with various prevalence and clinical implications.

Objectives

Methods

Results

Discussion

Conclusion