Interstitial Pneumonia With Autoimmune Features: Overview of Proposed Criteria and Recent Cohort Characterization
The accurate diagnosis of interstitial lung disease is essential for optimal prognostication and management. Although connective tissue disease is among the most common causes of interstitial lung disease, some patients have features suggestive of autoimmunity without meeting criteria for a specific connective tissue disease. To help define and study this disease entity more uniformly, a 2015 research statement proposed consensus-based criteria and coined the term “interstitial pneumonia with autoimmune features” (IPAF). In this review, we summarize and compare previously proposed criteria to characterize these patients, provide an overview of the IPAF criteria, and highlight recent investigations aimed at characterizing IPAF cohorts. Thereafter, we call attention to questions that have arisen with the application of the IPAF criteria and discuss future areas of study.