[Interstitial lung diseases - historical development, current status, future prospects]

Sarcoidosis and lung fibrosis were first described by histopathology in the 19th century. Since then a large number of different forms of diffuse parenchymal lung diseases has been identified. Although all these diseases manifest in the lung interstitium, there is a wide range of predominanthy inflammatory to purely fibrotic disease processes. Accordingly, anti-inflammatory treatment is successful in the former, whereas for the latter an effective medical therapy is lacking. Gene technology has recently led to results which have fundamentally changed our understanding of the pathophysiology of fibrosing lung disease. Early and differential diagnosis has much improved with the help of high-resolution computed tomography. Recent clinical trials in patients with idiopathic pulmonary fibrosis have shown at least some effectiveness for the antioxidant treatment approach using high-dosed N-acetylcysteine as well as for the use of pirfenidone. Importantly, these studies have proven that well-designed treatment trials are feasible in this patient population. This has kindled the hope that, based on a better understanding of the pathophysiology, new targeted therapies will prove to be successful in the future.