View Test

Laboratory:

Clinical Biochemistry (METABOLIC)

Test Name:

FRACTIONATED METANEPHRINES, RANDOM OR 24H URINE - (U)

Test Code: MNPH

Clinical Information:

Test Indications:
Elevation of Metanephrine and/or Normetanephrine about 2 to 50-fold the upper limit of normal are typically seen in pheochromocytoma. False-positive tests for pheochromocytoma may be seen in patients on antipsychotic medications. The neuroleptic malignant syndrome may also be seen in some patients on neuroleptic drugs including the newer agents currently available. Medications reported to cause false-positive testing for pheochromocytoma include acetaminophen, phenoxybenzamine, amitryptyline, labetolol, haloperidol, levodopa, tamsulosin, venlafaxine, hydrochlorothiazide, buspirone, lamotrigine, and aripiprazole.

Collection Devices:

Preferred Device:	1 - Urine Collection Container, Random 100 mL
Alternate Device:	1 - Urine Collection Container - 24 h Urine Collection Container - 24 h Manufacturer: VWR Scientific Products/Simport Plastics Catalogue #: CA73960-110

Random urines with or without acid preservative are acceptable. Samples preserved with 6N HCl are acceptable when other tests requiring preservative are ordered on same collection.

Specimen Required:

Urine: 10.0 mL

Special Processing: Prepare two aliquots for random or 24h urine

No preservative is required, acidified urine is acceptable.
One aliquot for urine creatinine to Automated chemistry can be sent refrigerated and the
second aliquot for Metanephrine testing should be frozen within 4 hours of collection.

Referral:

Refer to JA110-50-01A 24 Hour Urine Processing Flow Chart
JA110-50-01B Random Urine Processing Flow Chart

Shipping & Storage: Store and ship frozen

Testing Laboratory (MB):

HSC Clinical Biochemistry

Mass Spectrometry/Metabolic Lab

204-787-4530

Requisition:

_SH Urine Testing Requisition (R250-10-95)

Reference Values:

AGE                 MNPH               NMNPH
Units in μmol/mmol creat           (m=male; f=female)

0 - 1 mo:           < 0.8                 < 5.0
2 - 3 mo:           < 0.5                 < 3.0
4 - 6 mo:           < 0.4                 < 1.7
7 - 12 mo:         < 0.3                 < 1.2
13 - 36 mo:       < 0.2                 < 0.6
3 - 8 y:              < 0.19               < 0.44
9 - 40 y:            < 0.12               < 0.26
41 - 70 y:          < 0.16               < 0.35 (m)         < 0.40 (f)
Over 70 y:         < 0.20               < 0.40 (m)         < 0.45 (f)

Method of Analysis: Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Availability:

Within 10 Days

For urgent testing consult Clinical Biochemist on Duty at 431-276-4861