[Diffuse infiltrative lung diseases and fibrosis].

The clinician confronted to the diagnosis of infiltrative lung disease has to consider a wide spectrum of aetiologies. Among them, diffuse fibrosing interstitial lung disease is characterized by the deposition of collagen within alveolar structures. Either acute alveolar injury or chronic inflammatory alveolitis can induce pulmonary fibrosis. Basic research investigates the cells, the cytokines, and the extracellular matrix involved in the perpetuation of the fibropoliferative process.