[Role of bronchoalveolar lavage in analysis of diffuse pulmonary diseases].

Bronchoalveolar lavage (BAL) is often referred to as "Liquid biopsy of the lung". We reviewed the usefulness of BAL in the analysis of diffuse pulmonary diseases, focussing on the influences of smoking on cellular and soluble components in BAL, what causes the discrepancy between findings in BAL fluids and those in biopsy specimens and how cardiovascular system is influenced during this procedure. BAL offers a practical approach to not only academic, but clinical analysis such as therapeutic guide and prognosis.