Joyce Lee

Acute exacerbation of idiopathic pulmonary fibrosis has been defined as an acute, clinically significant, respiratory deterioration of unidentifiable cause. The objective of this international working group report on acute exacerbation of idiopathic pulmonary fibrosis was to provide a comprehensive update on the topic. A literature review was conducted to identify all relevant English text publications and abstracts. Evidence-based updates on the epidemiology, etiology, risk factors, prognosis, and management of acute exacerbations of idiopathic pulmonary fibrosis are provided. Finally, to better reflect the current state of knowledge and improve the feasibility of future research into its etiology and treatment, the working group proposes a new conceptual framework for acute respiratory deterioration in idiopathic pulmonary fibrosis and a revised definition and diagnostic criteria for acute exacerbation of idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic lung disease with an overall poor prognosis. A simple-to-use staging system for IPF may improve prognostication, help guide management, and facilitate research. OBJECTIVE: To develop a multidimensional prognostic staging system for IPF by using commonly measured clinical and physiologic variables. DESIGN: A clinical prediction model was developed and validated by using retrospective data from 3 large, geographically distinct cohorts. SETTING: Interstitial lung disease referral centers in California, Minnesota, and Italy. PATIENTS: 228 patients with IPF at the University of California, San Francisco (derivation cohort), and 330 patients at the Mayo Clinic and Morgagni-Pierantoni Hospital (validation cohort). MEASUREMENTS: The primary outcome was mortality, treating transplantation as a competing risk. Model discrimination was assessed by the c-index, and calibration was assessed by comparing predicted and observed cumulative mortality at 1, 2, and 3 years. RESULTS: Four variables were included in the final model: gender (G), age (A), and 2 lung physiology variables (P) (FVC and Dlco). A model using continuous predictors (GAP calculator) and a simple point-scoring system (GAP index) performed similarly in derivation (c-index of 70.8 and 69.3, respectively) and validation (c-index of 69.1 and 68.7, respectively). Three stages (stages I, II, and III) were identified based on the GAP index with 1-year mortality of 6%, 16%, and 39%, respectively. The GAP models performed similarly in pooled follow-up visits (c-index ≥71.9). LIMITATION: Patients were drawn from academic centers and analyzed retrospectively. CONCLUSION: The GAP models use commonly measured clinical and physiologic variables to predict mortality in patients with IPF.

Many patients with an idiopathic interstitial pneumonia (IIP) have clinical features that suggest an underlying autoimmune process but do not meet established criteria for a connective tissue disease (CTD). Researchers have proposed differing criteria and terms to describe these patients, and lack of consensus over nomenclature and classification limits the ability to conduct prospective studies of a uniform cohort.The "European Respiratory Society/American Thoracic Society Task Force on Undifferentiated Forms of Connective Tissue Disease-associated Interstitial Lung Disease" was formed to create consensus regarding the nomenclature and classification criteria for patients with IIP and features of autoimmunity.The task force proposes the term "interstitial pneumonia with autoimmune features" (IPAF) and offers classification criteria organised around the presence of a combination of features from three domains: a clinical domain consisting of specific extra-thoracic features, a serologic domain consisting of specific autoantibodies, and a morphologic domain consisting of specific chest imaging, histopathologic or pulmonary physiologic features.A designation of IPAF should be used to identify individuals with IIP and features suggestive of, but not definitive for, a CTD. With IPAF, a sound platform has been provided from which to launch the requisite future research investigations of a more uniform cohort.