Lipidomic profiling of serum and pancreatic fluid in chronic pancreatitis.

OBJECTIVES: Oxidative stress is intimately involved in the pathogenesis of chronic pancreatitis (CP), and its quantification may represent a useful biomarker. The aim was to determine whether oxidized fatty acid (OxFA) levels in serum and/or pancreatic fluid are elevated in CP.
METHODS: Patients evaluated for abdominal pain were classified into 3 groups (controls, mild CP, and severe CP). Serum and secretin-stimulated pancreatic fluid samples were stored under conditions to minimize artificial oxidation. Ten arachidonic and linoleic acid oxidation products were simultaneously measured using liquid chromatography-electrospray ionization-tandem mass spectrometry.
RESULTS: Most OxFAs were significantly elevated in the serum of patients with mild and severe CP compared to controls and correlated with structural features on endoscopic ultrasound. For example, the mean (SD) ratio of serum 13-HODE to its precursor linoleic acid was 0.03 (0.004) in controls, 0.06 (0.02) in mild CP, and 0.10 (0.04) in severe CP (analysis of variance, P = 0.004) and had a strong correlation with endoscopic ultrasound features (Spearman r = 0.84, P < 0.001). In the pancreatic fluid, statistically significant increases of OxFA products were observed in mild CP compared to controls.
CONCLUSIONS: Oxidized fatty acid products are increased in the serum and pancreatic fluid of patients with CP, suggesting a potential role as biomarkers. ABBREVIATIONS: AA - arachidonic acidANOVA - analysis of varianceAP - acute pancreatitisCP - chronic pancreatitisePFT - endoscopic pancreatic function testEUS - endoscopic ultrasoundHPLC - high-pressure liquid chromatographyHETE - hydroxy-eicosatetranoic acidHODE - hydroxy-octadecadienoic acidLA - linoleic acidLC-ESI-MS/MS - liquid chromatography-electrospray ionization-tandem mass spectrometryM - molarOxFA - oxidized fatty acidsPFT - pancreatic function test.