[Idiopathic lung fibrosis]

Idiopathic pulmonary fibrosis (IPF), also called interstitial pneumonia or fibrosing alveolitis, is a progressive interstitial lung disease of unknown origin. Two distinct forms are known which differ in course, morphologic features and cytological findings in bronchoalveolar lavage: a cellular "desquamative interstitial pneumonia" and a hypocellular and more fibrotic "usual interstitial pneumonia". The two types appear to represent different stages of the same disease. The clinical findings in IPF are dyspnoea, unproductive cough, clubbing and rales. Pulmonary function tests reveal restriction, reduced diffusion capacity and hypoxaemia during exercise. Chest X-rays show localized linear or nodular densities usually accentuated at the lung bases; in 10% of patients with IPF, chest radiography is normal. To assess the inflammatory process bronchoalveolar lavage and transbronchial or open lung biopsy have proven necessary. Before beginning treatment the activity of the inflammatory process and degree of lung function impairment should be established. Therapy of IPF is unspecific and its aim is to suppress alveolitis and the fibrotic process. Corticosteroids are the initial therapy. If there is no improvement after two months, immunosuppressive agents are added. Regular clinical and functional follow-up is required. Course and prognosis vary in different forms of IPF. Without treatment, median survival in the cellular form is over 10 years and in the hypocellular form between 3.2 and 5.6 years. Only 12-30% of patients respond to antiinflammatory treatment.