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Test Code MCMRU Mast Cell Mediators, 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 MCM24 / Mast Cell Mediators, 24 Hour, Urine.



Specimen Required


Patient Preparation:

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

2. Patients taking aspirin or nonsteroidal anti-inflammatory drugs (NSAID) may have decreased concentrations of prostaglandin F2 alpha (23BP). If possible, the patient should discontinue use for 2 weeks or 72 hours, respectively, before specimen collection.

Supplies: Urine Container, 60 mL (T313)

Collection Container/Tube: Plastic urine container

Submission Container/Tube: Plastic, 60-mL urine bottle

Specimen Volume: 20 mL

Collection Instructions:

1. Collect a random urine specimen within a few hours of symptom onset.

2. No preservative.


Useful For

Evaluating patients at risk for mast cell activation syndrome (eg, systemic mastocytosis) using random urine collections

Profile Information

Test ID Reporting Name Available Separately Always Performed
CRTFR Creatinine, Random, U No Yes
RLTE1 Leukotriene E4, Random, U Yes Yes
R23B1 2,3-dinor 11B-Prostaglandin F2a Yes Yes
RNMH1 N-Methylhistamine, Random Yes Yes

Method Name

CRT2F: Enzymatic Colorimetric Assay

RLTE1, R23B1, RNMH1: Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Mast Cell Mediators, Random, U

Specimen Type

Urine

Specimen Minimum Volume

10 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Frozen 28 days

Reference Values

LEUKOTRIENE E4:

≤104 pg/mg creatinine

 

2,3-DINOR 11B-PROSTAGLANDIN F2a:

<1802 pg/mg creatinine

 

N-METHYLHISTAMINE:

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

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

>16 years: 30-200 mcg/g creatinine

 

CREATININE:

≥18 years old: 16-326 mg/dL

Reference values have not been established for patients who are younger than 18 years.

Day(s) Performed

Monday, Tuesday, Thursday

Report Available

2 to 9 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

82570

84150

82542

LOINC Code Information

Test ID Test Order Name Order LOINC Value
MCMRU Mast Cell Mediators, Random, U In Process

 

Result ID Test Result Name Result LOINC Value
CRTFR Creatinine, Random, U 2161-8
620245 N-Methylhistamine, Random, U 13781-0
620241 Leukotriene E4, Random, U 33343-5
620243 2,3-dinor 11B-Prostaglandin F2a 97658-9