Ordering Recommendation

Aid in evaluation of patient with allergic signs and symptoms, such as anaphylaxis. May assist when diagnosing and monitoring mast-cell activation disorders or when evaluating histamine production over a longer time frame.

Mnemonic
NMETHYL U
Methodology

Quantitative Liquid Chromatography/Tandem Mass Spectrometry/Colorimetry

Performed

Varies

Reported

3-10 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation

Patient must not be taking monoamine oxidase inhibitors (MAOIs) or aminoguanidine as these medications increase N-methylhistamine (NMH) levels.

Collect

24-hour urine.

Specimen Preparation

From a well-mixed 24-hour collection transfer 5 mL urine to an ARUP Standard Transport Tube. (Min: 3 mL)
Test is not performed at ARUP; separate specimens must be submitted when multiple tests are ordered.

Storage/Transport Temperature

Refrigerated. Also acceptable: Room temperature or frozen.

Unacceptable Conditions
Remarks

Collection duration and urine volume must be provided for testing.

Stability

Ambient: 28 days; Refrigerated: 28 days; Frozen: 28 days

Reference Interval

By Report

Interpretive Data



No compliance statements are in use for this test.

Note
Hotline History
N/A
CPT Codes

82542

Components
Component Test Code* Component Chart Name LOINC
2011035 Collection Duration 13362-9
2011036 Urine Volume 28009-9
2011037 N-Methylhistamine, 24 Hr Urine 44340-8
2011038 Creatinine Concentration, 24 Hr Urine 2161-8
3002790 Creatinine, 24 Hr Urine
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • 1-Methylhistamine
  • Histamine Metabolites
  • Urinary N-Methylhistamine
N-Methylhistamine, 24-Hour Urine

Mayo Clinic Laboratories