Free metanephrines

Keywords: Metanephrines, Plasma metanephrines, Plasma free metanephrines

Specimen:

Plasma

Method:

HPLC, LC-MS/MS.

Reference Interval:

These may vary depending on the method and are age specific.

An example of LC-MS/MS RIs:

Metanephrine < 300 pmol/L

Normetanephrine < 660 pmol/L

Application:

Detection of catecholamine producing tumours. Some drugs other substances can interfere with this assay - consult pathologist.

Interpretation:

Elevated levels are seen in Phaeochromocytoma, Neuroblastoma or Ganglioneuroblastoma.

Metanephrine concentrations increase with age.

Elevations typical of Phaeochromocytoma are:

Metanephrine > 1200 pmol/L

Normetanephrine > 2190 pmol/L

Intermediate elevations (metanephrine 300-1200 pmol/L, and/or normetanephrine (660-2190 pmol/L) are often seen with medication interference.

Reference:

Eisenhofer G, Peitzsch M. Clin Chem 2014; 60: 1486-1499.

Eisenhofer G et al. Pharmacol Rev 2004; 5656:331-349.