ABSTRACT
This chapter reviews bronchoalveolar lavage (BAL) as a clinical and research tool applicable to the study of inhalational lung disease. A number of investigators have used BAL methodology to study the pathogenesis of pulmonary oxygen toxicity. D. L. Delacroix and colleagues have studied carefully the concentrations of various proteins in the BAL fluid of normals and patients with interstitial lung disease using sensitive immunonephelometric and immunoradiometric assays. An important assumption underlying the use of BAL to reflect the status of the airways and alveoli is that the cellular components in BAL fluid accurately represent those cells found on the epithelial surface of the lower respiratory tract and in the lung parenchyma. R. M. Bowen and colleagues characterized a urokinase-type plasminogen activator molecule in the alveolar macrophages and BAL fluid of humans and hamsters. In addition to macrophages, lymphocytes, and neutrophils, other respiratory tract cells may be found in small numbers in BAL fluid.
