| Test Name: |
N-METHYLHISTAMINE, 24-HOUR URINE |
| Test Code: |
2193875 |
| Alias: |
LAB11639
|
| CPT Code(s): |
82542
|
| Test Includes: |
N-Methylhistamine, 24 Hour, Urine
Creatinine, 24 Hour, Urine
|
| Preferred Specimen: |
5mL aliquot of 24 hour urine |
| Container: |
Aliquot Tube, 5 mL
Sterile Cup |
| Collection Instructions: |
Collection Instructions:
1. Collect urine for 24 hours.
2. No preservative.
3. Aliquot into plastic tube and send refrigerated. |
| Transport Temperature: |
Refrigerated |
| Stability: |
Room Temp: 14 days
Refrigerated (preferred): 28 days
Frozen: 28 days |
| Rejection Criteria: |
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. |
| Limitations: |
If the total volume provided is less than 500 mL, this test will be canceled and NMHR ordered and performed. |
| Schedule: |
Set Up: Tuesday, Thursday
TAT: 3 to 7 days |
| Method: |
NMH1D: Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
CRT24: Enzymatic Colorimetric Assay |
| Performing Lab: |
Mayo Clinic Laboratories #NMH24 |
| Clinical Significance: |
N-methylhistamine (NMH) is the major metabolite of histamine, which is produced by mast cells. Increased histamine production is seen in conditions associated with increased mast-cell activity, such as allergic reactions, but also in mast-cell proliferation disorders, particularly mastocytosis.
Mastocytosis is a rare disease. Its most common form, urticaria pigmentosa (UP), affects the skin and is characterized by multiple persistent small reddish-brown lesions that result from infiltration of the skin by mast cells. Systemic mastocytosis is caused by the accumulation of mast cells in other tissues and can affect organs such as the liver, spleen, bone marrow, and small intestine. The mast-cell proliferation in systemic mastocytosis can be either benign or malignant. In children, benign systemic mastocytosis tends to resolve over time, while in most, but not all adults, the disease is progressive. Systemic mastocytosis may or may not be accompanied by UP. Patients with UP or systemic mastocytosis can have symptoms ranging from itching, gastrointestinal distress, bone pain, and headaches; to flushing and anaphylactic shock. |
| Use: |
Screening for and monitoring of mastocytosis and disorders of systemic mast-cell activation, such as anaphylaxis and other forms of severe systemic allergic reactions using 24-hour urine collection specimens
Monitoring therapeutic progress in conditions that are associated with secondary, localized, low-grade persistent, mast-cell proliferation and activation such as interstitial cystitis |
| Reference Ranges: |
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:
Males: 930-2955 mg/24 hours
Females: 603-1783 mg/24 hours
Reference values have not been established for patients who are less than 18 years of age. |
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The CPT codes included in this publication are in accordance with Current Procedural Terminology, a publication of the American Medical Association. CPT codes are provided here for the convenience of our clients; however, correct coding often varies from one carrier to another, and HealthLab may bill specific carriers using codes other than those shown. Clients who bill for services should verify the code(s) with the applicable payor to confirm that their use is appropriate in each case.
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| Test Type: |
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