Porphyrins, Quantitative, Random, Urine
Use
Preferred test to begin assessment for congenital erythropoietic porphyria and porphyria cutanea tarda and during symptomatic periods for acute intermittent porphyria, hereditary coproporphyria, and variegate porphyria when specimen transport will not exceed 72 hours. Testing includes porphobilinogen and aminolevulinic acid, which are useful in the evaluation of the acute porphyrias.
Special Instructions
This random urine collection allows for the diagnosis to be established and treatment to be initiated quickly. Order only when specimen will be received within 72 hours; if longer, order both PQNU (24‑hour) and ALAUR and follow collection guidelines. Ship specimen in amber bottle to protect from light; include a list of medications the patient is taking.
Limitations
Porphobilinogen (PBG) and porphyrins are susceptible to degradation at high temperature, pH below 5.0, and exposure to light. Not appropriate for diagnosing conjugated or unconjugated hyperbilirubinemia syndromes. Neither erythropoietic protoporphyria nor X‑linked dominant protoporphyria are detected. Ethanol and certain medications/drugs/toxins can interfere, leading to porphyrin elevations not indicative of porphyria.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 93707-8
- 25166-0
- 34314-5
- 96795-0
- 34352-5
- 25167-8
- 2811-8
- 39782-8
- 49291-8
- 18771-6
Result Turnaround Time
2-4 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
20 to 50 mL
Minimum Volume
15 mL
Container
Amber, 60‑mL urine container
Collection Instructions
Collect a random urine specimen; pH must be above 5.0; protect from light.
Patient Preparation
Patient must not consume any alcohol for at least 24 hours before collection.
Storage Instructions
Frozen immediately following collection; ship in amber bottle to protect from light.
Causes for Rejection
pH below 5.0; not protected from light; not frozen.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | Unacceptable |
| Frozen | 72 hours |