Test Overview
Method
Various
Method Description
N-Methylhistamine: LC-MS/MS
Creatinine: Enzymatic Colorimetric Assay
Result Included
N-Methylhistamine; Creatinine
Aliases/Synonyms
1-Methylhistamine;Histamine Metabolites;Urinary N-Methylhistamine;NMHR;NMH;N-Methylhistamine
Specimen
Specimen Type
UrineRandom urine collections are preferred for patients with episodic symptoms, for example in the context of allergic reactions, brought on by specific environmental factors.
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; order N-Methylhistamine, 24 Hour Urine
Containers
Collection Containers
Mid-Stream Urine Container
Volume
Sample Volume
5 ml
Minimum Volume
3 ml
Patient Preparation
Patient must not be taking monoamine oxidase inhibitors (MAOI) or aminoguanidine as these medications increase N-methylhistamine (NMH) levels.
Collection & Handling
Collection Instructions
Collect a random urine specimen within a few hours of symptom onset. No Preservative.
Handling Information
Store and send cold or frozen.
Stability
| Ambient | Refrigerated | Frozen |
|---|---|---|
| 14 days | 28 days | 28 days |
Performance & Interpretation
Turnaround Time
11 days
Results
Name
Units
Reference Range
Conversion
-
N-methylhistaminemcg/g creatinine0-5 y: 120-510
6-16 y: 70-330
> 16 y:30-200 -
Creatininemg/dLInterpret with other clinical dtata
Referral Location
Out-of-Country
Interface & Setup
HL7 Interface Codes
| Order Code | Result Name | Result Codes | Units |
|---|---|---|---|
| NMHR U | N-Methylhistamine, Random, U | 63387 | mcg/g Cr |
| Creatinine, Random, U | 63388 | mg/dL |
Test Version
Last Updated
2022-09-29