Received on July 27, 2006
Accepted on October 26, 2006

Lipids, Lipoproteins, and Cardiovascular Risk Factors

Potential Utility of Plasma Fatty Acid Analysis in the Diagnosis of Cystic Fibrosis

¹ Division of Laboratory Medicine, Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA
² Department of Pediatrics, University of Massachusetts Memorial Health Care and University of Massachusetts Medical School, Worcester, MA
³ Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA

^* To whom correspondence should be addressed. E-mail: mlaposata{at}partners.org.

Background: An altered distribution of fatty acids in cells and tissues is found in patients with cystic fibrosis (CF). In this study, we assessed the potential role of plasma fatty acid analysis in the diagnosis of CF.

Methods: In this 2-part study, we first used gas chromatography-mass spectrometry to analyze fatty acids in plasma from 13 CF patients and 11 controls without CF. We then used the fatty acid distribution data to identify the fatty acids or multiple fatty-acid calculations most effective in identifying CF patients. Part 2 of the study was a blinded analysis of 10 CF patients and 9 controls to directly test the effectiveness of the diagnostic parameters for CF identified from the plasma fatty acid analysis.

Results: In the nonblinded trial, the multiplication product of (18:2 n-6) x (22:6 n-3; each as percentage of total plasma fatty acid) was the most effective indicator for distinguishing patients with CF from controls (P = 0.0003). In part 2 (the blinded trial), this multiplication product was also the most effective indicator for distinguishing CF patients from controls (P = 0.0008).

Conclusions: The product of (18:2 n-6) x (22:6 n-3) is effective for distinguishing CF patients from persons without CF. This diagnostic marker may have value as an alternative to the sweat chloride test in selected patients being evaluated for CF.