EDITORIAL NSIP, UIP, and the ABCs of idiopathic interstitial pneumonias

Diffuse interstitial lung disease (ILD) is a general term encompassing a broad range of largely unrelated condi-tions which share the propensity to cause breathlessness and/or cough, while resulting in bilateral abnormal opaci-ties of various types on conventional chest radiographs or computed tomography (CT) scans. The idiopathic intersti-tial pneumonias are a subset of diffuse ILDs characterized by an expansion of the interstitial compartment (i.e. that portion of the lung parenchyma sandwiched between the epithelial and endothelial basement membranes) by an in-filtrate of inflammatory cells. The inflammatory infiltrate is sometimes accompanied by fibrosis, either in the form of abnormal collagen deposition or a proliferation of fibro-blasts capable of collagen synthesis. Our understanding of the idiopathic interstitial pneumo