[Properties of inflammatory cells in broncho-alveolar lavage in pulmonary fibrosis].

Bronchoalveolar lavage in alveolitis and fibrotic lung diseases serves mainly (1) as a tool facilitating diagnosis and prognosis, and (2) to provide insight into the pathophysiology of tissue destruction and fibrotic processes. The interaction between macrophages, lymphocytes, polymorphonuclear leukocytes and fibroblasts is in part controlled by polypeptides (cytokines), some of whose structures and genes are well characterized. The macrophage seems to be a key mediator between the immune and non-immune cells. The major cytokines produced by macrophages which may play a role in fibrotic processes are interleukin-1, tumor necrosis factor/cachectin, platelet-derived growth factor, and interferons alpha and beta. Once it becomes possible in vivo to quantify cellular activation and production of these cytokines, these diseases will be easier to monitor and more rational therapeutic approaches will be found.