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N-Methylhistamine, 24 Hour, Urine

Additional Codes

Miscellaneous Test

Reporting Name

N-Methylhistamine, U

Useful For

Screening for and monitoring of mastocytosis and disorders of systemic mast-cell activation, such as anaphylaxis and other forms of severe systemic allergic reactions

 

Monitoring therapeutic progress in conditions that are associated with secondary, localized, low-grade persistent, mast-cell proliferation and activation such as interstitial cystitis


Specimen Required


Container/Tube: Plastic, 5-mL tube (T465)

Specimen Volume: 5 mL

Collection Instructions:

1. Collect urine for 24 hours.

2. No preservative.

Additional Information:

1. 24-Hour volume is required.

2. 24-Hour collection is preferred, but random specimen is also acceptable.

3. See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens in Special Instructions for multiple collections.


Specimen Type

Urine

Specimen Minimum Volume

3 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated (preferred) 8 days
  Frozen  14 days
  Ambient  24 hours

Day(s) and Time(s) Performed

Tuesday, Thursday; 10 a.m.

Performing Laboratory

Mayo Medical Laboratories in Rochester

Method Name

NMH: Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

NCTU: Enzymatic Colorimetric Assay

Method Description

N-methylhistamine (NMH) is extracted from urine using solid-phase extraction. The elute is analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and quantified using a stable isotope labeled internal standard.(Martens-Lobenhoffer J, Neumann HJ: Determination of 1-methylhistamine and 1-methylimidazole acetic acid in human urine as a tool for the diagnosis of mastocytosis. J Chromatogr B Biomed Sci Appl 1999;721[1]:135-140)

Reference Values

0-5 years: 120-510 mcg/g creatinine

6-16 years: 70-330 mcg/g creatinine

>16 years: 30-200 mcg/g creatinine

Test Classification

This test was developed and its performance characteristics determined by Laboratory Medicine and Pathology, Mayo Clinic. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

82542

LOINC Code Information

Test ID Test Order Name Order LOINC Value
NMHIN N-Methylhistamine, U 44340-8

 

Result ID Test Result Name Result LOINC Value
NCTU_ Creatinine Conc 2161-8
21589 N-Methylhistamine, U 44340-8
TM73 Collection Duration 13362-9
VL63 Urine Volume 3167-4

Reject Due To

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

NA

Profile Information

Test ID Reporting Name Available Separately Always Performed
NMH N-Methylhistamine, U No Yes
NCTU Creatinine Concentration No Yes

Urine Preservative Collection Options

Ambient

Yes

Refrigerated

Preferred

Frozen

Yes

6N HCl

Yes

50% Acetic Acid

Yes

Na2CO3

Yes

Toluene

Yes

6N HNO3

Yes

Boric Acid

Yes

Thymol

No