Pulmonary alveolar proteinosis: analysis of pulmonary washings

Bronchopulmonary washings from a patient with pulmonary alveolar proteinosis who underwent therapeutic pulmonary lavage were examined. There were large amounts of protein and lipids of which main classes were phospholipid, cholesterol and free fatty acid. The major component of phospholipids recovered from the washings was lecithin rich in palmitic acid. We also found a high IgG level in the washings. Both the findings of free cholesterol in high concentration in the washings and the electrophoretic pattern of protein in the washings suggested that the alveoli-filling material of our patient was not wholely derived from passive transudation of plasma constituents.