The revised ATS/ERS/JRS/ALAT diagnostic criteria for idiopathic pulmonary fibrosis (IPF) - practical implications

Respiratory Research

Table 2 ATS/ERS criteria for diagnosis of idiopathic pulmonary fibrosis in absence of surgical lung biopsy (2000)^†[1]

Major criteria
Exclusion of other known causes of ILD such as certain drug toxicities, environmental exposures, and connective tissue diseases Abnormal pulmonary function studies that include evidence of restriction (reduced VC, often with an increased FEV₁/FVC ratio) and impaired gas exchange [increased P(A-a)O₂, decreased PaO₂ with rest or exercise or decreased DL_CO] Bibasilar reticular abnormalities with minimal ground glass opacities on HRCT scans Transbronchial lung biopsy or BAL showing no features to support an alternative diagnosis
Minor criteria
Age >50 yr Insidious onset of otherwise unexplained dyspnoea on exertion Duration of illness >3 months Bibasilar, inspiratory crackles (dry or “Velcro”-type in quality)

Definition of abbreviations: BAL=bronchoalveolar lavage; DL_CO=diffusing capacity of the lung for CO; HRCT=high-resolution computerised tomography; ILD=interstitial lung disease; P(A–a)O₂=alveolar–arterial pressure difference for O₂; VC=vital capacity.
^†In the immunocompetent adult, the presence of all of the major diagnostic criteria as well as at least three of the four minor criteria increases the likelihood of a correct clinical diagnosis of IPF.

ISSN: 1465-993X