Detection of Plasma Catecholamines in Human Pheochromocytoma and Primary Hypertension Based on Liquid Chromatography Tandem Mass Spectrometry

Background The measurement of plasma catecholamines (CAs) including dopamine (DA), epinephrine (E), and norepinephrine (NE) and theirderivatives including metanephrine (MN), normetanephrine (NMN), vanillylmandelic acid (VMA), and homovanillic acid (HVA) hasbeen used in the diagnosis of pheochromocytoma and paraganglioma (PPGL) and primary hypertension (PH) but are typically detectedindividually when clinical testing. In this study, pre-column derivatization with dansyl chloride (DNS-Cl) combined with anultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed to simultaneously quantifyHVA, VMA, MN, NMN, DA, E, and NE in the plasma from patients with PPGL and PH. Methods Plasma samples were extracted by acetonitrile and derivatized with DNS-Cl, followed by reverse phase separation and triplequadruple detection. Quantification of the CAs and their derivatives in 10 PPGL, 10 PH, and 100 healthy subjects was performedby UPLC-MS/MS analysis. Results All the values of detected CAs/derivatives were in the linearity ranges of the fitted curves. The expression levels of theseven CAs in the PPGL and PH patients were significantly higher than the healthy controls, suggesting increased CA productionin the former. There were significant differences in plasma NE, NMN, and VMA levels between the PPGL and PH patients, butthere was no significant difference in plasma E, MN, DA, and HVA. A discriminant analysis showed that 90% of the final caseswere classified correctly based on the detected CAs/derivatives. Conclusions Our results show that the combined detection of the seven CAs/derivatives could be used for the clinical diagnosis of PPGLand PH.