Increased mole fraction of arachidonic acid in bronchial phospholipids in patients with cystic fibrosis.

The fatty acid pattern of the phospholipids in the bronchial secretion of patients with cystic fibrosis (CF) showed an increase of the mole fraction of arachidonic acid (AA) in most phospholipid classes compared to normals. Increase of AA in some classes was also found in patients with chronic bronchitis and in patients chronically colonized with Pseudomonas aeruginosa but in the diphosphatidylglycerol, lysophosphatidylethanolamine and sphingomyelin phospholipids, high fractions of AA was found exclusively in CF patients. Arachidonic acid was found to attain the highest ratios in CF in seven of the nine major bronchial phospholipids compared to the controls. There was no difference in the ratio saturated/unsaturated fatty acids between the CF patients and the control groups. A tendency towards unsaturation of the fatty acids in the bronchial secretion seems to be characteristic of infection and inflammation but AA appears to be more markedly increased in CF. Thus, the recorded changes may be characteristic for CF and not secondary to infection and/or inflammation in general, nor to P. aeruginosa colonization.