Test ID NMHR1 N-Methylhistamine, Random, Urine
Ordering Guidance
Patients with chronic mast cell activation often have chronically elevated N-methylhistamine (NMH) levels and will sometimes have intermittent NMH elevations. In these cases, a 24-hour urine collection is preferred. See NMH24 / N-Methylhistamine, 24 Hour, Urine.
Specimen Required
Only orderable as part of a profile. For more information see: NMHR / N-Methylhistamine, Random, Urine
Supplies: Sarstedt 5 mL Aliquot Tube (T914)
Container/Tube: Plastic, 5-mL tube
Specimen Volume: 5 mL
Collection Instructions:
1. Collect a random urine specimen.
2. No preservative.
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 as a part of a random urine collection profile
Monitoring therapeutic progress in conditions that are associated with secondary, localized, low-grade persistent, mast-cell proliferation and activation such as interstitial cystitis
Method Name
Only orderable as part of a profile. For more information see:
NMHR / N-Methylhistamine, Random, Urine
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
N-Methylhistamine, RandomSpecimen Type
UrineSpecimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Urine | Refrigerated (preferred) | 28 days | |
Ambient | 28 days | ||
Frozen | 28 days |
Reference Values
Only orderable as part of a profile. For more information see:
NMHR / N-Methylhistamine, Random, Urine
0-5 years: 120-510 mcg/g creatinine
6-16 years: 70-330 mcg/g creatinine
>16 years: 30-200 mcg/g creatinine
Day(s) Performed
Tuesday, Thursday
Performing Laboratory

Test Classification
This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
82542
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
NMHR1 | N-Methylhistamine, Random | 13781-0 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
605015 | N-Methylhistamine, Random, U | 13781-0 |