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HelpTest 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 RTLE4) | 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, USpecimen Type
UrineSpecimen 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
Day(s) Performed
Monday, Tuesday, Thursday
Report Available
2 to 9 daysPerforming 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 |