Newcastle Laboratories

Metanephrines, plasma

Clinical Background:

Phaeochromocytoma and functional paraganglioma are rare neuroendocrine tumours that are characterised by excessive secretion of catecholamines. With such low disease prevalence, initial biochemical...

Phaeochromocytoma and functional paraganglioma are rare neuroendocrine tumours that are characterised by excessive secretion of catecholamines. With such low disease prevalence, initial biochemical testing should reliably exclude or confirm the presence of a catecholamine-secreting tumour. Measurement of free (unconjugated) metanephrines in plasma has been shown to be a highly sensitive test for the detection of phaeochromocytoma. With a diagnostic sensitivity of 98% and specificity of 92%, a negative test result virtually rules out the diagnosis.

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Test Documents

Test Details

  • Discipline:

    Biochemistry

    Biochemistry

  • Specimen Container Adult:

    Purple - EDTA

    Purple - EDTA

  • Specimen Container Paediatric:

    Pink - EDTA

    Pink - EDTA

  • Minimum Volume Adult:

    1 mL blood

    1 mL blood

  • Minimum Volume Paediatric:

    1 mL blood

    1 mL blood

  • Special Requirement:

    Avoid stress.

    Samples viable up to 30 min from collection without ice and for 60 mins with ice.

    Avoid stress.

    Samples viable up to 30 min from collection without ice and for 60 mins with ice.

  • Sample Stability:

    EDTA plasma samples are stable at -20°C to -40°C for at least 6 months.

    EDTA plasma samples are stable at -20°C to -40°C for at least 6 months.

  • Transport Requirements:

    Sample must be transported to the laboratory on ice within 30 mins of collection.

    For external laboratories, collected on ice and separtate within 30mins, sample must be stored and transported frozen.

    Sample must be transported to the laboratory on ice within 30 mins of collection.

    For external laboratories, collected on ice and separtate within 30mins, sample must be stored and transported frozen.

  • Quality Assurance:

    RCPA Quality Assurance Program

    RCPA Quality Assurance Program

  • Interpretation:

    Plasma metanephrine or normetanephrine values greater than 4 times the upper reference interval are highly suggestive of the presence of phaeochromocytoma/paraganglioma. Elevated results are report...

    Plasma metanephrine or normetanephrine values greater than 4 times the upper reference interval are highly suggestive of the presence of phaeochromocytoma/paraganglioma. Elevated results are reported with appropriate comments.

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  • Reference Ranges:

    Metanephrine:

    Paediatric: No ranges available.
    Adult: <510 pmol/L


    Normetanephrine:

    Paediatric: No ranges available.
    Adult: <1180 pmol/L

     

    3-methoxytyramine:

    Paediatric: No ranges available.
    Adult: ...

    Metanephrine:

    Paediatric: No ranges available.
    Adult: <510 pmol/L


    Normetanephrine:

    Paediatric: No ranges available.
    Adult: <1180 pmol/L

     

    3-methoxytyramine:

    Paediatric: No ranges available.
    Adult: <180 pmol/L


    These reference ranges are based on a seated population. Ranges for samples taken in the supine posture are also now included on all reports.

    For a discussion of the issue of posture and relevant reference ranges please see our Plasma Metanephrines User Guide (available from link under Test Documents on this page).

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  • Factors Affecting Result:

    Drugs can interfere analytically or pharmacodynamically with measurement of plasma or urinary metanephrines, potentially causing false positive results. The LC-MS/MS method for plasma free metaneph...

    Drugs can interfere analytically or pharmacodynamically with measurement of plasma or urinary metanephrines, potentially causing false positive results. The LC-MS/MS method for plasma free metanephrines is considered to be far less susceptible to analytical interference.

    Many drugs are now known to increase catecholamine and metabolite concentrations, including tricyclic antideppressant's, selective serotonin reuptake inhibitors, serotonin and noradrenaline reuptake inhibitors, α- and β- adrenergic receptor blockers, calcium channel blockers, monoamine oxidase inhibitors, Levo(L)-Dopa, methyldopa and several stimulant/sympathomimetic drugs.

    Ideally patients should discontinue all medications that may affect plasma and urinary catecholamine or metanephrine concentrations prior to sampling. In practice, it is not always possible to discontinue medication before testing and it might be better to repeat testing only when initial tests are elevated.

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  • Other Info:

    Plasma metanephrine analysis is performed by HPLC-MS/MS.

    Plasma metanephrine analysis is performed by HPLC-MS/MS.

  • Routine Contact Name:

    Duty Biochemist

  • Routine Telephone:

    Freeman: 0191 244 8889
    RVI: 0191 282 9719

    Freeman: 0191 244 8889
    RVI: 0191 282 9719

  • Routine Email:

    - For external users: TNU-Tr.duty.biochemist@nhs.net

    - For Trust users: DutyBiochemist@nuth.nhs.uk

  • Specialist Test:

    Yes

    Yes

Availability:

Available during full access hours
Assayed as service demands
Site of analysis: Freeman

Turn Around:

Within 2 weeks

Send To:

Department of Blood Sciences
Freeman Hospital
Freeman Road
Newcastle upon Tyne
NE7 7DN

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