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Test Code NMHR1 N-Methylhistamine, Random, Urine


Ordering Guidance


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.



Specimen Required


Only orderable as part of a profile. For more information see NMHR / N-Methylhistamine, Random, Urine.

 

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

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Container/Tube: Plastic, 5-mL tube

Specimen Volume: 5 mL

Collection Instructions:

1. Collect a random urine specimen.

2. No preservative.


Useful For

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 random urine collection 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, Random

Specimen Type

Urine

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated (preferred) 28 days
  Ambient  28 days
  Frozen  28 days

Reference Values

Only orderable as part of a profile. For more information see NMHR / N-Methylhistamine, Random, Urine.

 

0-5 years: 120-510 mcg/g creatinine

6-16 years: 70-330 mcg/g creatinine

>16 years: 30-200 mcg/g creatinine

Day(s) Performed

Monday, Wednesday, Friday

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

82542

LOINC Code Information

Test ID Test Order Name Order LOINC Value
NMHR1 N-Methylhistamine, Random 13781-0

 

Result ID Test Result Name Result LOINC Value
605015 N-Methylhistamine, Random, U 13781-0

Report Available

3 to 7 days

Specimen Minimum Volume

3 mL

Specimen Retention Time

14 days