What Do Gene Expression Profiles Tell Us?
Victor J. Thannickal, M.D. University of Michigan, Ann Arbor, Michigan Athol U. Wells, M.D. Royal Brompton Hospital, Fulham, London, United Kingdom The 2002 Joint Consensus Statement by the American Thoracic Society (ATS) and the European Respiratory Society (ERS) defined a new classification of the idiopathic interstitial pneumonias (IIPs) (1), primarily intended as a framework for studies of these difficult diseases. In some respects, the ATS/ERS initiative has been clinically helpful. Idiopathic pulmonary fibrosis (IPF), the most prevalent and malignant of the IIPs (2, 3), is now diagnosed with greater precision than ever before, based on the proposed histopathologic and clinical criteria. However, the entity of nonspecific interstitial pneumonia (NSIP) has posed major diagnostic problems for practicing clinicians. The prevailing difficulty has been the clinical heterogeneity of NSIP. High-resolution computed tomography findings in NSIP include features suggestive of organizing pneu
