International consensus statement on idiopathic pulmonary fibrosis.

In the new millennium, idiopathic pulmonary fibrosis (IPF) is not what it was thought to be 20 years ago. In the past, the term was used for a heterogeneous group of interstitial lung disorders of unknown cause, after exclusion of possible exposures or associated conditions. Now IPF is more narrowly defined as a distinct clinical entity, with certain characteristic clinical, radiological and morphological features; specifically, the pattern of usual interstitial pneumonia (UIP) on surgical lung biopsy [1]. Historically, several histopathological subsets of the family of the idiopathic interstitial pneumonias were considered part of the spectrum of IPF (or cryptogenic fibrosing alveolitis (CFA), the preferred term in the British literature). The Liebow classification of 1969, divided the idiopathic interstitial pneumonias into several histological subsets: usual interstitial pneumonia (UIP), desquamative interstitial pneumonia (DIP), bronchiolitis obliterans with interstitial pneumonia (BIP), lymphoid interstitial pneumonia (LIP), and giant cell interstitial pneumonia (GIP). LIP and GIP were dropped from this classification because many of the former cases were found to be lymphoproliferative disorders and many of the latter were cases of hard metal pneumoconiosis. Recently, KATZENSTEIN and MYERS [2] proposed that the entities acute interstitial pneumonia (AIP or diffuse alveolar damage of unknown aetiology) and nonspecific interstitial pneumonia (NSIP) be added to the spectrum of idiopathic interstitial pneumonia. Furthermore, the specific features of the UIP pattern have been more clearly defined, allowing for better separation of this lesion from the other patterns, particularly NSIP. The major reason for separating IPF/UIP, the most common idiopathic interstitial pneumonia, from the other entities, was the increasingly reported severe prognosis in the IPF/UIP subset compared to the other subgroups of the idiopathic interstitial pneumonias. Median survival for the more narrowly defined IPF patients is now only 2.8 yrs, compared to approximately 5 yrs in previous studies, which often included cases with NSIP and DIP patterns on lung biopsy or were clinical diagnoses [3 – 5]. In early 2000, guidelines were published for the diagnosis and management of IPF by the American Thoracic Society (ATS), European Respiratory Society (ERS) and American College of Chest Physicians (ACCP), which took these new developments into consideration [1]. This editorial will highlight the key issues and conclusions from this consensus report for the ERJ readers and ERS members. The level of evidence for the recommendations is largely that of expert opinion developed by consensus. There is no supportive evidence from well conducted randomised controlled trials. The following is a summary of this consensus statement. Key conclusions or recommendations from the panel of experts included the following: 1. UIP is the histopathological pattern that identifies patients with IPF. Other patterns such as DIP, respiratory bronchiolitis-associated interstitial lung disease (RBILD), NSIP, LIP, AIP, and idiopathic bronchiolitis obliterans organising pneumonia (idiopathic BOOP) are considered separate entities and are to be excluded from the group of patients with IPF. 2. Clinical criteria are specified for determining the presumptive diagnosis of IPF and distinguishing IPF from other diffuse parenchymal lung diseases. 3. Surgical lung biopsy is recommended in most patients, especially those with suspected IPF who have clinical, physiological, or radiological features that are not typical for IPF and who are without contraindications to surgery. A major purpose is to distinguish UIP from other subsets of the idiopathic interstitial pneumonia that have a better response to available treatment. 4. No data exist that adequately document that any of the current treatment approaches improves survival or the quality of life for patients with IPF. 5. The committee suggests that therapy is not indicated for all patients with IPF. If therapy is recommended to a patient, it should be started at the first identification of clinical or physiological evidence of impairment or documentation of decline in lung function. 6. A combination of clinical, radiographical, and physiological parameters should be used to assess the clinical course and response to treatment of IPF. 7. Lung transplantation should be considered for those patients who experience progressive deterioration Committee Members: T.E. King (chairman), U. Costabel, J.F. Cordier, G.A. DoPico, R.M. Du Bois, D. Lynch, J. Myers, R. Panos, G. Raghu, D. Schwartz, C.M. Smith.