Chapter 74 - Idiopathic and Autoimmune Interstitial Lung Disease

Abstract

Interstitial lung disease is a broad category of heterogeneous diseases which share the common feature of inflammatory and fibrotic changes that primarily affect the alveoli and small airways. The two most common manifestations are idiopathic pulmonary fibrosis (IPF) and cryptogenic organizing pneumonia (COP), both of which can occur as “idiopathic” conditions or in association with several autoimmune diseases. Although both are classified as “lung disorders of unknown etiology,” there are multiple clues suggesting that autoimmune mechanisms play a role in the pathogenesis of both disorders. The focus of this chapter is to explore the link between autoimmune mechanisms underlying COP and IPF as models for autoimmune disorders of the lung. To do so, we will first discuss the history and the clinical features of COP and IPF, followed by a summary of the autoimmune, genetic, and environmental features, current concepts of pathogenesis, and the therapies currently available and under investigation for both disorders.