N-Methylhistamine, Random Urine
Also known as: NMETH RAN
Use
This test aids in the evaluation of patients with allergic signs and symptoms, such as anaphylaxis and other severe systemic allergic reactions. It is particularly useful for diagnosing and monitoring mast-cell activation disorders and evaluating histamine production over a longer period. Chronic mast-cell activation can lead to elevated levels of N-methylhistamine (NMH), and this test can provide useful diagnostic and monitoring information in these cases.
Special Instructions
Patient preparation involves avoiding the intake of monoamine oxidase inhibitors (MAOIs) or aminoguanidine as these medications can increase N-methylhistamine levels. Specimen collection should occur within a few hours of symptom onset.
Limitations
The test is not performed at ARUP Laboratories, and separate specimens must be submitted for multiple tests when ordered. The stability of the specimen is as follows: 2 weeks at ambient temperature, 28 days refrigerated, and 28 days frozen. The test has not been cleared or approved by the FDA, though it has been developed and its performance characteristics determined in compliance with CLIA requirements by Mayo Clinic.
New York Approved
Methodology
Mass Spectrometry
Biomarkers
LOINC Codes
- 13781-0
- 2161-8
Result Turnaround Time
7-12 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
5 mL
Minimum Volume
3 mL
Container
ARUP standard transport tubes
Collection Instructions
Collect urine specimen within a few hours of symptom onset.
Patient Preparation
Patient must not be taking monoamine oxidase inhibitors (MAOIs) or aminoguanidine.
Storage Instructions
Refrigerated transport; also acceptable at room temperature or frozen.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 2 weeks |
| Refrigerated | 28 days |
| Frozen | 28 days |