Recent advances in the pathogenesis and clinical evaluation of pulmonary fibrosis.

Interstitial lung diseases (ILDs) are a group of heterogeneous disorders, either idiopathic or associated with injurious or inflammatory causes, in which the major site of damage is the lung interstitium. For a long time, knowledge regarding pathogenesis was trivial and there were difficulties in diagnosing and subsequently treating these diseases. During the past decade, however, there has been an impressive development in the field of ILDs. Idiopathic pulmonary fibrosis, the most common and fatal form of ILD, was initially believed to be due to an inflammatory response to unknown lung injury, whereas nowadays it is believed to be the result of multiple injuries at different sites of the lung followed by aberrant repair. The integration of clinical, radiological and histological data, namely a multidisciplinary team (MDT) approach, has provided grounds for a more accurate diagnosis of ILDs, and helped the identification of different entities and development of different therapeutic approaches. However, because of the complexity of ILDs, even this approach may fail to establish a confident diagnosis. How should the clinician behave in this case and what are the pitfalls of the MDT approach? In addition, since diagnosis is the major predictor of prognosis, are there any other tools available to predict prognosis?