Bronchoalveolar lavage as a diagnostic tool.

Bronchoalveolar lavage (BAL) provides an important diagnostic tool that can facilitate the diagnosis of various diffuse lung diseases. BAL fluid can be analyzed to determine white blood cell (WBC) profiles and to detect respiratory pathogens. Although BAL is seldom useful as a "stand-alone" diagnostic test for the diagnosis of diffuse infiltrative lung disease, when combined with clinical data and high-resolution computed tomography of the chest, BAL WBC profiles can contribute significantly to the diagnosis of specific forms of interstitial lung disease (ILD). Additionally, BAL can play a very important role in the diagnosis of respiratory infection, and it is useful in monitoring the lung allograft and in evaluating pediatric lung disease. Examination of BAL cells or acellular components of BAL via gene microarray technology or proteomic analyses may allow BAL to assume a more prominent role in diagnosis and management of lung disease in the near future.