Idiopathic pulmonary fibrosis (IPF) is a dreadful, chronic and irreversibly progressive fibrosing disease, leading to death all patients affected, and IPF acute exacerbations constitute the most devastating complication during its clinical course. IPF exacerbations are subacute/acute, clinically significant deteriorations of unidentifiable cause that usually transform the slow and more or less steady disease decline to the unexpected appearance of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), ending to death. The histological picture is that of diffuse alveolar damage (DAD), the tissue counterpart of ARDS, upon usual interstitial pneumonia (UIP) the tissue equivalent of IPF. ALI/ARDS and acute interstitial pneumonia share with IPF exacerbations the tissue damage patte...