Lipid composition of airway secretions from patients with asthma and patients with cystic fibrosis.

Lipids from the particulate material obtained from pulmonary lavage of patients with asthma and cystic fibrosis were isolated and characterized. In both cases, lipids constituted 30 to 40 per cent of the dry insoluble material and phosphatidylcholine was the predominant lipid. Significant amounts of phosphatidylethanolamine and phosphatidyglycerol were present. Hexosyl ceramides, spingomyelin, phosphatidylinositol, phosphatidylserine, and lyso(bis)phosphatidic acid were present as minor lipid components. Appreciable quantities of neutral lipids were also found. Significant amounts of lysophosphatides and free fatty acids were present only in the lavage sediment from patients with asthma, and not in patients with cystic fibrosis. Phosphatidylcholine, lysophosphatidycholine, sphingomyelin, and phosphatidylglycerol of asthmatic lavage, but not cystic lavage, were highly saturated, containing mostly palmitic acid.