Interstitial lung abnormality (ILA) and nonspecific interstitial pneumonia (NSIP)

Abstract

This review article aims to address mysteries existing between Interstitial Lung Abnormality (ILA) and Nonspecific Interstitial Pneumonia (NSIP). The concept and definition of ILA are based upon CT scans from multiple large-scale cohort studies, whereas the concept and definition of NSIP originally derived from pathology with evolution to multi-disciplinary diagnosis. NSIP is the diagnosis as Interstitial Lung Disease (ILD) with clinical significance, whereas only a part of subjects with ILA have clinically significant ILD. Eventually, both ILA and NSIP must be understood in the context of chronic fibrosing ILD and progressive ILD, which remains to be further investigated.

Keywords: AIP, acute interstitial pneumonia; ATS/ERS, American Thoracic Society/European Respiratory Society; BIP, bronchiolitis obliterans with interstitial pneumonia; BOOP, bronchiolitis obliterans organizing pneumonia; CT; CTD, connective tissue disease; Connective tissue disease (CTD); DIP, desquamative interstitial pneumonia; GGO, ground-glass opacities; GIP, giant cell interstitial pneumonia; HRCT; HRCT, high-resolution CT; IIP, idiopathic interstitial pneumonia; ILA, interstitial lung abnormality; ILD, interstitial lung disease; Interstitial lung abnormality (ILA); Interstitial lung disease (ILD); LIP, lymphoid interstitial pneumonia; NSIP, nonspecific interstitial pneumonia; Nonspecific interstitial pneumonia (NSIP); Pulmonary fibrosis; RB-ILD, respiratory bronchiolitis-associated interstitial lung disease; UIP, usual interstitial pneumonia; fNSIP, fibrosing nonspecific interstitial pneumonia.