Pirfenidone treatment in a patient with IPF and possible initial hypersensitivity pulmonitis

The diagnosis of idiopathic pulmonary fibrosis (IPF) requires exclusion of other known causes of interstitial lung disease (ILD) (e.g., domestic and occupational environmental exposures, systemic connective tissue disease, and drug toxicity), the presence of a ‘usual interstitial pneumonia’ (UIP) pattern on high resolu- tion computed tomography (HRCT), and specific combinations of HRCT and histopathologic patterns in pa- tients subjected to surgical lung biopsy (SLB). A clear diagnosis and early treatment with currently the only ap- proved anti-fibrotic drug, pirfenidone, represents the standard of care for the treatment of mild-to-moderate IPF. This case report describes a patient with possible initial hypersensitivity pneumonitis and subsequent di- agnosis of IPF with late development of pulmonary hypertension, and who was a candidate for lung transplan- tation. The patient showed slow progression of IPF during pirfenidone treatment in the CAPACITY and RE-CAP studies.