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Order 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. Patients taking monoamine oxidase inhibitors (MAOI) or aminoguanidine may have increased N-methylhistamine (NMH) levels. If medically feasible, patient must not take MAOI or aminoguanidine for 3 weeks before specimen collection. For more information see Cautions.

2. Patients taking aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) may have decreased concentrations of prostaglandin F2 alpha (23BP). If medically feasible, the patient should not take aspirin for 2 weeks or NSAIDs for 72 hours before specimen collection.

3. Patients taking 5-lipoxygenase inhibitor zileuton (Zyflo) may have decreased concentrations of leukotriene E4 (LTE4). If medically feasible, the patient should not take zileuton for 48 hours 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, (order RLTE4) Yes
R23B1 2,3-dinor 11B-Prostaglandin F2a Yes, (order 23BPR) Yes
RNMH1 N-Methylhistamine, Random Yes, (order NMHR) 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
Urine Frozen 28 days

Reject Due To

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

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: Not established

≥18 years: 16-326 mg/dL

Method Description

N-methylhistamine:

N-methylhistamine is extracted from urine using solid-phase extraction. The elute is analyzed using liquid chromatography tandem mass spectrometry (LC-MS/MS) and quantified using a stable isotope labeled internal standard.(Martens-Lobenhoffer J, Neumann HJ. Determination of 1-methylhistamine and 1-methylimidazoleacetic acid in human urine as a tool for the diagnosis of mastocytosis. J Chromatogr B Biomed Sci Appl. 1999;721[1]:135-140; Lueke AJ, Meeusen JW, Donato LJ, Gray AV, Butterfield JH, Saenger AK. Analytical and clinical validation of an LC-MS/MS method for urine leukotriene E4: A marker of systemic mastocytosis. Clin Biochem. 2016;49[13-14]:979-982. doi:10.1016/j.clinbiochem.2016.02.007)

 

2,3-Dinor-11beta-prostaglandin F2alpha:

2,3-Dinor-11beta-prostaglandin F2alpha (23BPG) is quantified in urine by LC-MS/MS. Deuterium-labeled 23BPG internal standard (d4-11BPGF2a) is added to all controls and specimens, which are then liquid/liquid extracted. The eluent is evaporated, and samples/QC are then reconstituted prior to LC-MS/MS analysis.(Unpublished Mayo method)

 

Leukotriene E4:

Leukotriene E4 (LTE4) is quantified in urine via multiplexed LC-MS/MS. Deuterium-labeled LTE4 internal standard is added to all standards/controls/samples, which are then filtered. After additional sample clean-up, this eluent is analyzed by LC-MS/MS.(Unpublished Mayo method)

 

Creatinine:

The enzymatic method is based on the determination of sarcosine from creatinine with the aid of creatininase, creatinase, and sarcosine oxidase. The liberated hydrogen peroxide is measured via a modified Trinder reaction using a colorimetric indicator. Optimization of the buffer system and the colorimetric indicator enables the creatinine concentration to be quantified both precisely and specifically.(Package insert: Creatinine plus Ver 2. Roche Diagnostics; V15.0, 03/2019)

Day(s) Performed

Monday, Tuesday, Thursday

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

82570

84150

82542