Autoimmune interstitial lung disease

Interstitial lung diseases (ILDs) describe a large group of parenchymal disorders with a heterogeneous course and presentation. They are common in most autoimmune diseases (ADs), increasing morbidity and mortality among them. Pathogenesis is a result of both hereditary (epigenetics and genetics) and environmental factors, resulting in humoral and cellular immune responses, including fibroblast activation. ILDs are classified depending on their radiologic and pathologic patterns. In ADs, the most common patterns are nonspecific interstitial pneumonia (NSIP), usual interstitial pneumonia (UIP), organizing pneumonia (OP), lymphoid interstitial pneumonia (LIP), and diffuse alveolar damage (DAD). A holistic approach through nonpharmacological and pharmacological therapies is necessary to achieve better outcomes. Further research is still needed to develop tailored therapies. This chapter aims to describe the main elements to understand, diagnose, and evaluate ILDs associated with ADs in clinical practice.