Present status of bronchoalveolar lavage in interstitial lung disease

Purpose of review: Sampling the detachable cells and acellular lining secretions of the human respiratory tract by bronchoalveolar lavage (BAL) is a means of obtaining relevant components from the airways and alveolar areas for research use and clinical analysis in normals (controls) and patients with a wide spectrum of interstitial lung diseases (ILDs). This review attempts to discuss recent findings from BAL studies that provide insight into pathogenic mechanisms of ILDs and/or assist in diagnosing disease activity. RECENT FINDINGS: BAL analysis and usefulness are reviewed for the major forms of ILDs. In addition, some perspective about this sampling method is given and the context for BAL is provided for the respective disease, either for diagnosis or research use. SUMMARY: Whereas BAL findings continue to impact on understanding disease pathogenesis and this may be its major use now, BAL fluid components, cells in particular, are not correlated well with activity of disease nor for monitoring disease progress or response to treatment. For a few rarer ILDs, BAL fluid characteristics may strongly support a diagnosis.