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Specimen Collection Manual and Test Catalog

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N-METHYLHISTAMINE, URINE

Geisinger Epic Procedure Code:  LAB1039    Geisinger Epic ID:  52081

SPECIMEN COLLECTION
Specimen type: 

Random urine


Preferred collection container: 
Specimen required: 

5 mL random urine (no preservative); minimum 3 mL


Special notes: 

Collect a random urine specimen within a few hours of symptom onset. No preservative.


Patient preparation: 

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



SPECIMEN PROCESSING
Transport temperature: 

Refrigerated (cold packs).


Specimen stability: 

Room temperature: 14 days. Refrigerated: 28 days. Frozen: 28 days.



TEST DETAILS
Additional information: 

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.


CPT code(s):  82542, 82570
Note: The billing party has sole responsibility for CPT coding.  Any questions regarding coding should be directed to the payer being billed.
The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.

Methodology: 
Enzymatic Colorimetric
Liquid Chromatography Mass Spectrometry (LC/MS)
Synonyms: 

Quest test code 39604, N-Methylhist


Clinical significance: 

Screening for and monitoring of mastocytosis and disorders of systemic mast-cell activation, such as anaphylaxis and other forms of severe systemic allergic reactions using random urine specimens. Monitoring therapeutic progress in conditions that are associated with secondary, localized, low-grade persistent, mast-cell proliferation and activation such as interstitial cystitis.


Review Date:  12/05/2024

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