The role of bronchoalveolar lavage in the assessment of diffuse lung diseases.

Bronchoalveolar lavage is a safe and simple technique for sampling the inflammatory cells of the lung. However, while its use in the evaluation of pulmonary pathogenic mechanisms is both well accepted and described, its clinical utility is more controversial. Marked variation in results may occur through variation in the lavage procedure. Standardisation of the lavage technique and laboratory processing of the specimen are essential for reliable results. This review examines the current clinical role of bronchoalveolar lavage in the assessment of patients with diffuse lung diseases, and immunocompromised patients with pulmonary infiltrates. In this latter category, for patients with Acquired Immunodeficiency Syndrome, lavage is of equal efficacy to lung biopsy and can establish the cause of pulmonary infiltrates in over 90% of cases. Bronchoalveolar lavage can detect abnormalities in patients with diffuse lung diseases prior to the development of irreversible fibrosis. Lavage features have been described for sarcoidosis, cryptogenic fibrosing alveolitis, extrinsic allergic alveolitis, connective tissue diseases, and asbestosis. In cryptogenic fibrosing alveolitis lavage data may be used to indicate a subsequent deterioration in the patient's condition, or predict a favourable response to therapy.