Idiopathic Pulmonary Fibrosis

Lynch, Joseph P.; Belperio, John A.

Idiopathic pulmonary fibrosis (IPF) is a specific clinicopathologic ­syndrome presenting in older adults with the predominant features: dyspnea, dry cough, restrictive defect on pulmonary function tests (PFTs), hypoxemia, characteristic abnormalities on high-resolution thin section computed tomographic (HRCT) scans, usual interstitial pneumonitis (UIP) pattern on lung biopsy. Surgical lung biopsy is the gold standard of diagnosis, but the diagnosis can be established in some cases by HRCT, provided the clinical features are consistent. The cause of IPF is unknown. However, IPF is more common in adults >60 years old, smokers (current or ex), and patients with specific occupational or noxious exposures. Familial IPF, associated with several distinct genetic mutations, accounts for 1.5–3% of cases. Unfortunately, the prognosis is poor, and most patients die of respiratory failure within 3–6 years of diagnosis. However, the course is highly variable. In some patients, the disease is fulminant, progressing to lethal respiratory failure within months, whereas the course may be indolent, spanning >5 years in some patients. Therapy has not been proven to alter the course of the disease or influence mortality, but recent studies with pirfenidone and tyrosine kinase inhibitors are promising. Lung transplantation is the best therapeutic option, but is limited to selected patients with severe, life-threatening disease and no contraindications to transplant.