Limited bronchoalveolar lavage (BAL) as an extension of fiberoptic bronchoscopy has permitted the recovery of airway-alveolar
space cells and soluble substances in the extracellular lining fluid that have been used diagnostically and as research specimens
in patients with a variety of lung diseases and in normal subjects for the study of lung host defenses. During the past three
decades, use of BAL specimens has stimulated immunologic and cellular research of pulmonary diseases, which has provided significant
insight into local host immunity, inflammation, fibrogenesis, asthma mechanisms, and infections. From this research new methods
of antifibrotic therapy of interstitial pulmonary fibrosis, for example, have followed. Moreover, BAL applications have greatly
enhanced professional interest in the field of pulmonary medicine. This review attempts to analyze the history and impact
of BAL, appraise its current status, and assess its future usefulness.
Understanding the immunopathogenesis of many lung diseases is predicated on obtaining in situ specimens from affected lung tissue and airways. BAL provides a direct sample that can be compared with an endobronchial
or transbronchial biopsy tissue specimen and with cellular and immunologic components in the vascular circulation. Thus, the
recovery of BAL fluid and its components involved directly with a disease process or continguous with interstitial tissue
permits a much more detailed assessment of new cellular mediators and cytokines participating in the pathologic process. Furthermore,
subjecting BAL cells to microarrays of DNA to discern what genes are activated will be one step closer to identifying intracellular
processes involved or deranged. Identification of causative factors may solve questions of causation, so that preventive strategies
or definitive therapy can be used.
Key words: Bronchoalveolar lavage—Fiberoptic bronchoscopy—Diffuse interstitial lung disease
Accepted for publication: 8 August 2000