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HelpTest Code NMH1D N-Methylhistamine, 24 Hour, Urine (Non-Orderable)
Ordering Guidance
Random urine collection is preferred for patients with episodic symptoms, eg, in the context of allergic reactions, brought on by specific environmental factors; order NMHR / N-Methylhistamine, Random, Urine.
Specimen Required
Only orderable as part of a profile. For more information see NMH24 / N-Methylhistamine, 24 Hour, Urine.
Patient Preparation: Patients taking monoamine oxidase inhibitors (MAOIs) may have increased levels of N-methylhistamine. If medically feasible, for 2 weeks before specimen collection, patient should not take MAOIs.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Container/Tube: Plastic, 5-mL tube
Specimen Volume: 5 mL
Collection Instructions:
1. Collect urine for 24 hours.
2. No preservative.
3. Aliquot into plastic tube and send at refrigerate temperature.
Useful For
Only orderable as part of a profile. For more information see NMH24 / N-Methylhistamine, 24 Hour, Urine.
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 profile
Monitoring therapeutic progress in conditions that are associated with secondary, localized, low-grade persistent, mast-cell proliferation and activation such as interstitial cystitis
Reporting Name
N-Methylhistamine, 24 Hr, USpecimen Type
UrineSpecimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Urine | Refrigerated (preferred) | 28 days |
| Frozen | 28 days | |
| Ambient | 14 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
Only orderable as part of a profile. For more information see NMH24 / N-Methylhistamine, 24 Hour, Urine.
0-5 years: 85-369 mcg/g creatinine
6-16 years: 48-238 mcg/g creatinine
>16 years: 19-143 mcg/g creatinine
Method Description
Isotopically labeled N-methylhistamine (NMH) is added to the sample as an internal standard (IS). NMH and IS are then purified from urine using solid phase extraction. The eluate is analyzed using liquid chromatography-tandem mass spectrometry.(Unpublished Mayo method)
Day(s) Performed
Monday, Wednesday, Friday
Specimen Retention Time
14 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
82542
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| NMH1D | N-Methylhistamine, 24 Hr, U | 44340-8 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 605159 | N-Methylhistamine, 24 Hr | 44340-8 |
Report Available
3 to 7 daysSpecimen Minimum Volume
3 mL