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HelpTest Code LAB1994 Porphobilinogen, Quantitative, Random, Urine
Additional Codes
PORPHOB
Reporting Name
Porphobilinogen, QN, Random, USCH Clinical System Name: Urine Porphobilinogen Quant Random
Useful For
First-order test for evaluating a suspected acute porphyria: acute intermittent porphyria, hereditary coproporphyria, and variegate porphyria
Shipping Instructions
Ship specimen protected from light.
Necessary Information
Include a list of medications the patient is currently taking.
Specimen Required
Patient Preparation: Patient must not consume any alcohol for at least 24 hours prior to collection.
Supplies: Urine Container-Amber, 60 mL (T596)
Specimen Volume: 20 mL
Collection Instructions:
1. Collect a random urine specimen.
2. No preservative necessary but pH must be above 5.0.
3. Specimens should be protected from light and frozen immediately following collection.
Specimen Type
UrineSpecimen Minimum Volume
15 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Frozen (preferred) | 7 days | LIGHT PROTECTED |
| Refrigerated | 7 days | LIGHT PROTECTED |
Day(s) Performed
Monday through Friday
TAT: 4 - 8 days
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Method Description
Porphobilinogen (PBG) in urine is quantified by liquid chromatography tandem mass spectrometry after addition of stable isotope-labeled PBG internal standard and solid phase extraction.(Ford RE, Magera MJ, Kloke KM, et al. Quantitative measurement of porphobilinogen in urine by stable-isotope dilution liquid chromatography-tandem mass spectrometry. Clin Chem. 2001 September;47[9]:1627-1632; Stolzel U, Doss MO, Schuppan D. Clinical guide and update on porphyrias. Gastroenterology. 2019;157(2):365-381.e4. doi:10.1053/j.gastro.2019.04.050)
Reference Values
≤1.3 mcmol/L
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
84110
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PBGU | Porphobilinogen, QN, Random, U | 2811-8 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 29365 | Porphobilinogen, U | 2811-8 |
| 29366 | Interpretation (PBGU) | 59462-2 |
| 35032 | Reviewed By | 18771-6 |
Testing Algorithm
For more information see:
-The Heme Biosynthetic Pathway
Special Instructions
Report Available
2 to 4 daysReject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Forms
If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
Aliases: Acute Intermittent Porphyria (AIP), Hereditary Coproporphyria (HCP), PBG (Porphobilinogen), Variegate Porphyia (VP)