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N-Methyl Histamine, Urine [10243X]

Test Code


CPT Code(s)




Preferred Specimen(s)

5 mL 24-Hour Urine
Instructions: Collection Instructions: Collect 24-hour
urine with no preservatives.
Icteric specimens are no longer rejected. Total volume
is required. Record on both the specimen container and
the request form.
Urine Preservative Collection Options
Note: The addition of preservative or application of
temperature controls must occur within 4 hours of
completion of the collection: 6N HCl, 50% Acetic Acid,
Na(2)CO(3), Toluene, 6N HNO(3), Boric Acid, Thymol.

Minimum Volume

3 mL

Alternative Specimen(s)

5 mL Random Urine (Min3 mL)
Urine Container, leak-proof (No Preservative);
5 mL 24-Hour Urine (Min3 mL)
Urine Container, leak-proof (30 mL 6N HCl); Refrigerated;

5 mL 24-Hour Urine (Min3 mL)
Urine Container, leak-proof (25 mL of 50% acetic acid);
5 mL 24-Hour Urine (Min3 mL)
Urine Container, leak-proof ( 5 g Na2CO3); Refrigerated;

5 mL 24-Hour Urine (Min3 mL)
Urine Container, leak-proof (10 g boric acid);

Specimen Container

Urine Container, leak-proof

Transport Temperature


Specimen Stability

Room Temperature: 24 hours
Refrigerated: 8 days
Frozen: 14 days


Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS) • Enzymatic Colorimetric Assay

Performing Laboratory

Mayo Medical Laboratories
200 First Street SW
Rochester, MN 55905

Setup Days

Tuesday, Thursday Morning
Report available: 5 Days

Reference Range(s)

N-Methylhistamine, Urine
0-5 years: 120-510 mcg/g creatinine
6-16 years: 70-330 mcg/g creatinine
>16 years: 30-200 mcg/g creatinine

Clinical Significance

Screening for and monitoring of mastocytosis and
disorders of systemic mast-cell activation, such as
anaphylaxis and other forms of severe systemic allergic
Monitoring therapeutic progress in conditions that are
associated with secondary, localized, low-grade
persistent, mast-cell proliferation and activation such
as interstitial cystitis.

LOINC®' Code(s)

The Result and LOINC information listed below should not be used for electronic interface maintenance with Quest Diagnostics. Please contact the Quest Diagnostics Connectivity Help Desk for more information at 800-697-9302.

NOTE: The codes listed in the table below are not orderable Test Codes.

Result NameLOINC CodeComponent Name
49317N-Methyl Histamine, Urine12714-2N-methylhistamine
ASTMRCVDResults Received19146-0Reference lab test results
AVOLUMEURINE VOLUME3167-4Specimen volume

Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.

The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

LOINC assignment is based on a combination of test attributes, including the method used by the performing laboratory. For tests not performed by Quest Diagnostics, codes are assigned by the performing laboratory.

* The tests listed by specialist are a select group of tests offered. For a complete list of Quest Diagnostics tests, please refer to our Directory of Services.