Idiopathic Interstitial Pneumonias

Idiopathic interstitial pneumonias are a group of diffuse parenchymal lung diseases of unknown etiology with varying degrees of inflammation and fibrosis. They are classified into eight clinicopathological entities: idiopathic pulmonary fibrosis, nonspecific interstitial pneumonias, desquamative interstitial pneumonias, respiratory bronchiolitis–associated interstitial lung diseases, organizing pneumonias, acute interstitial pneumonias, lymphoid interstitial pneumonias, and pleuroparenchymal fibroelastosis. The diagnosis of idiopathic interstitial pneumonias is typically made through a clinical-radiological-pathological approach and requires an assessment from a multidisciplinary committee. For idiopathic pulmonary fibrosis, a defined set of radiological criteria has been established, enabling diagnosis with a sensitivity exceeding 90%. Bronchoscopic lung cryobiopsy has a high diagnostic yield and can be an alternative to lung biopsy in centers with experience in the area. The multidisciplinary committee is currently considered the gold standard in the area of interstitial lung diseases and therefore of idiopathic interstitial pneumonias. Currently, there are two anti-fibrotic treatments, nintedanib and pirfenidone, and a lung transplant might be necessary in the advanced stages.