Performance characteristics of an LC-MS/MS method for the determination of plasma metanephrines.
BACKGROUND
Catecholamines and their metabolites, metanephrines, are produced excessively in pheochromocytoma tumors of the chromaffin cells. Increased concentrations of these compounds produce symptoms and allow for clinical evaluation of disease. Historically, screening for such tumors by determination of catecholamines and metabolites in urine yielded false negative results in individuals with a genetic predisposition for the disease and those with paroxysmal hypertension. Analysis of metanephrines in plasma, however, is of decisive diagnostic importance. This test exhibits high sensitivity and specificity for the analytes produced by tumors.


METHODS
Plasma proteins are removed by solid phase extraction. Chromatographic isolation of the analytes and stable isotope internal standards is achieved by elution on a HILIC column connected to a UPLC MS/MS system. Metanephrines are measured using multiple reaction monitoring with an electrospray source operating in positive ion mode.


RESULTS
The method was validated for linearity, limit of quantification, accuracy, and precision. The method was accurate and correlated well to a comparison HPLC method. Potential interferences were evaluated.


CONCLUSIONS
Results from this LC-MS/MS assay enable clinical diagnosis of pheochromocytoma and aid in monitoring treatment outcomes.
ARUP Institute for Clinical and Experimental Pathology, Salt Lake City, UT 84108, USA.
Brian J
BJ
Petteys
Kendon S
KS
Graham
M Laura
ML
Parnás
Crystal
C
Holt
Elizabeth L
EL
Frank
D000310:Adrenal Gland Neoplasms / Q000097:blood* / Q000175:diagnosis; D002853:Chromatography, Liquid; D006801:Humans; D057230:Limit of Detection; D008676:Metanephrine / Q000031:analogs & derivatives* / Q000097:blood*; D010673:Pheochromocytoma / Q000097:blood* / Q000175:diagnosis; D012016:Reference Values; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry
D008676:Metanephrine