The role of bronchoalveolar lavage in diffuse lung diseases [Ruolo del BAL nello studio delle interstiziopatie polmonari diffuse]

The application of bronchoalveolar lavage (BAL) to the study of diffuse interstitial lung diseases (DLD) provided very important information about the complex reactions present at alveolar level in the various forms. The data till now obtained allowed to improve our understanding of the pathogenetic mechanisms and to contribute to the diagnosis and to the disease activity evaluation. The evaluation of cell pattern often associated with cell phenotype is widely used in clinical practice to distinguish the various forms and may be of diagnostic value in some cases, when the clinical picture is compatible or can aid to exclude other diseases. More sophisticated investigations such as the analysis of cytokine patterns to identify the type of immune response (Th1/Th2) and of mediators with different functions (profibrotic, proinflammatory etc.) or the identification of disease markers by new methods (genomic or proteomic studies) are research tools with future clinical application for diagnosis, prognosis and new treatment indication. Standardized protocols and guidelines are needed for correct clinical use of BAL. The recent literature on the role of BAL in DLD is reviewed.