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Geisinger Medical Laboratories Test Catalog
METANEPHRINES, FRACTIONATED, FREE, LCMSMS, PLASMA |
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Geisinger Epic Procedure Code: LAB2664
Geisinger Epic ID: 35275
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SPECIMEN COLLECTION |
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Specimen type: |
Plasma | |
Preferred collection container: |
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Specimen required: |
2.5 mL (minimum 1.5 mL) plasma from EDTA tube, refrigerated. | |
Special notes: |
Draw specimen in prechilled pink-top EDTA tube. The whole blood sample should be kept on wet ice until centrifuged. See Specimen Processing Instructions. | |
Patient preparation: |
Overnight fasting is preferred. Patient should avoid alcohol, coffee, tea, tobacco, and strenuous exercise before collection. | |
| SPECIMEN PROCESSING |
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Specimen processing instructions: |
Centrifuge within 2 hours of collection. Transfer plasma to leakproof aliquot and ship refrigerated. | |
Transport temperature: |
Refrigerated. | |
Specimen stability: |
Room temperatre: 4 hours. Refrigerated: 14 days. Frozen: 14 days. | |
Rejection criteria: |
Heparinized plasma, serum, CSF, and urine are unacceptable specimens types. Specimens received at room temperature are unacceptable. | |
TEST DETAILS |
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Reference interval: |
Metanephrines, Free < or = 57 pg/mL Normetanephrines, Free, < or = 148 pg/mL Total Free (MN + NMN) < or = 205 pg/mL Elevations > 4-fold upper reference range: strongly suggestive of a pheochromocytoma. Elevations > 1-4-fold upper reference range: significant but not diagnostic, may be due to medications or stress. Suggest running 24-hr urine fractionated metanephrines and/or serum Chromogranin A for confirmation. |
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CPT code(s): |
83835 | |
| Note: The billing party has sole responsibility for CPT coding. Any questions regarding coding should be directed to the payer being billed. The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only. | ||
Test includes: |
Metanephrine, normetanephrine and total metanephrine | |
Methodology: |
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) |
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Synonyms: |
Quest test code 19548 FMETPL
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Clinical significance: |
Normetanephrine (NM) and metanephrine (MN) are the extraneuronal catechol-o-methyl transferase (COMT) metabolites of the catecholamines norepinephrine and epinephrine, respectively. Measure of plasma metanephrines is more sensitive (but may be less specific) than measurement of catecholamines for the detection of pheochromocytoma. Proper interpretation of results requires awareness of recent medication/drug history (e.g., antihypertensive agents, alcohol, cocaine) and other preanalytical factors (e.g., stress, severe congestive heart failure, myocardial infarction) that influence release of catecholamines and metanephrines. | |