Essential fatty acid deficiency in relation to genotype in patients with cystic fibrosis.

OBJECTIVE

To determine if the serum phospholipid fatty acid pattern in patients with cystic fibrosis (CF) was related to the major cystic fibrosis transmembrane conductance regulator gene mutations.

METHODS

Patients with CF (n = 110) aged 3 months to 56 years were studied. Serum samples were analyzed for phospholipid fatty acid with gas-liquid chromatography, and cystic fibrosis transmembrane conductance regulator mutations were determined with standard methods.

RESULTS

Patients with CF had significantly lower molar percentages of linoleic acid and docosahexaenoic acid in the serum phospholipid than healthy controls (mean +/- standard deviation, 20.3 +/- 4.5 and 2.6 +/- 0.9 vs 22.4 +/- 2.2 and 3.1 +/- 0.7, respectively; P <.001). Palmitoleic and oleic acids were significantly increased (P <.001) but arachidonic acid was not different from controls. Homozygotes for DeltaF508 and heterozygotes/homozygotes for 394delTT showed significantly lower concentrations of linoleic acid and docosahexaenoic acid than the other groups. Low values were not correlated to anthropometric data or lung function. Patients with pancreatic insufficiency showed similar differences to those with sufficient pancreatic function, reflecting the different genotypes.

CONCLUSION

Serum concentrations of linoleic acid and docosahexaenoic acid were significantly lower in patients with severe cystic fibrosis transmembrane conductance regulator mutations, suggesting an association between the basic defect and abnormal essential fatty acid metabolism in CF patients.