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Test Code LABF5NUL 5'-Nucleotidase, Serum

Additional Codes

Test Name in EPIC  EPIC Test Code  Mayo Test ID
Nucleotidase 5
LABF5NUL
5NTD

 


Specimen Required


Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions: Centrifuge and aliquot serum into plastic vial.


Useful For

Aiding diagnosis and monitoring of hepatobiliary disease and bile duct obstructions

 

Ruling out bone pathology as the source of elevated serum alkaline phosphatase

Method Name

Coupled Enzyme Kinetic Assay

Reporting Name

5'-Nucleotidase, S

Specimen Type

Serum

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 14 days
  Frozen  90 days

Reject Due To

Gross hemolysis Reject
Gross lipemia OK
Gross icterus OK

Clinical Information

5'-Nucleotidase (5'NT) is an enzyme that catalyzes the hydrolysis of the phosphate group from 5'-nucleotides. Increased enzyme levels in sera are associated with certain forms of liver disease, such as intra- or extra-hepatic obstruction, and particularly in cases of hepatic carcinoma and in mastectomy patients with recurrent metastases. 5'NT is specific to hepatobiliary disease, which can make it useful in conjunction with other liver enzyme activity assays, like gamma glutamyl transferase, to differentiate between an increase in alkaline phosphatase due to cholestatic liver disease rather than bone disease (Paget disease).

Reference Values

<4.6 U/L

 

For International System of Units (SI) conversion for Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html.

Interpretation

An elevation of 5'-nucleotidase (5'NT) activity may be seen in all forms of liver disease, although the highest elevations are seen in intra- or extra-hepatic biliary obstruction.

 

5'-nucelotidase may be more specific for intrahepatic cholestasis than gamma glutamyl transferase.

 

Elevation of 5'NT activity is not associated with skeletal disease. Thus, measurement of 5'NT in serum can be used to differentiate observed elevations of alkaline phosphatase due to skeletal disease vs. hepatobiliary disease.

Cautions

Alkaline phosphatase (ALP) is known to cross-react with 5'-nucleotidase (5'NT) measurements. Placental ALP of 100 U/L gives a 5'NT result of 0.27 U/L. Accordingly, specimens with elevations of any ALP isoenzyme significantly above normal circulating activity must be interpreted cautiously.

 

5'-nucleotidase is neither specific nor sensitive enough to be used as a cancer screen.

 

Do not interpret serum 5' NT activity as absolute evidence of the presence or the absence of malignant disease. Use serum 5' NT in conjunction with information from the clinical evaluation of the patient and other diagnostic procedures.

 

Values obtained with different assay methods or kits may be different and cannot be used interchangeably.

Method Description

The Diazyme 5'-Nucleotidase (5'NT) assay is a coupled enzyme kinetic method where 5'NT facilitates the enzymatic hydrolysis of 5'-monophosphate to form inosine which is converted to hypoxanthine by purine nucleoside phosphorylase. Hypoxanthine is then converted to uric acid and hydrogen peroxide (H2O2) by xanthine oxidase. H2O2 is further reacted with N-Ethyl-N-(2-hydroxy-3-sulfopropyl)-3-methylaniline and 4-aminoantipyrine in the presence of peroxidase to generate quinone dye which is monitored in a kinetic manner and is proportional to the 5'NT activity which can be determined photometrically by an increase in absorbance at 550 nm compared to a calibration curve. One unit of 5'NT is defined as the amount of 5'NT that generates one micromole of inosine from IMP per min at 37° C. Testing is performed utilizing a closed development channel on the Roche cobas c502 module on the cobas 8000 analyzer.(Package insert: 5'-Nucleotidase Assay. Diazyme Laboratories, Inc.; 05/2022)

Day(s) Performed

Monday through Saturday

Report Available

1 to 3 days

Specimen Retention Time

2 weeks

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

83915

LOINC Code Information

Test ID Test Order Name Order LOINC Value
5NTD 5'-Nucleotidase, S 1690-7

 

Result ID Test Result Name Result LOINC Value
5NTD 5'-Nucleotidase, S 1690-7