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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. 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, USpecimen Type
UrineSpecimen Minimum Volume
10 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| 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 old: 16-326 mg/dL
Reference values have not been established for patients who are younger than 18 years.
Interpretation
Analytical reports within the scope of the individual assays will be provided when testing is complete.
Day(s) Performed
Monday, Tuesday, Thursday
Report Available
2 to 9 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
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 |