Porphyrins Quantitative, Random Urine (Sendout)

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General Information

Lab Name
Porphyrins Quantitative, Random Urine
Lab Code
RUPORR
Epic Name
Porphyrins, Quant, Random Urine (Sendout)
External Test Id
PQNRU
Description

Useful For: Assessment for congenital erythropoietic porphyria and porphyria cutanea tarda and during symptomatic periods for acute intermittent porphyria, hereditary coproporphyria, and variegate porphyria in random urine specimens.

Patient Preparation: Patient should abstain from alcohol for 24 hours prior to collection. Include a list of medications the patient is currently taking.

Ordering Note: This test is for random urine specimens only. For testing on timed specimens, refer to separate entry Porphyrins Quantitative, 24 Hour Urine (Sendout) [RUPORG].

Collection Note: Limited specimen stability. Collect Monday through Thursday only to ensure arrival and testing at Mayo Clinic Laboratories within 72 hours of collection.

Synonyms
Acute Intermittent Porphyria (AIP), Congenital Erythropoietic Porphyria (CEP), Coproporphyrin, Hereditary Coproporphyria (HCP), PBG (Porphobilinogen), Porphyria Cutanea Tarda (PCT), PQNRU, T596, Uroporphyrin, Variegate Porphyria (VP)
Components
Code Name
RUUPPR Uroporphyrin (Octa), Random Urine
RUHPPR Heptacarboxylporphyrins, Random Urine
RUHXPR Hexacarboxylporphyrins, Random Urine
RUPCPR Pentacarboxylporphyrins, Random Urine
RUCPPR Coproporphyrin (tetra), Random Urine
RUPRBR Porphobilinogen, Random Urine
RUPRIR Porphyrins Quantitative Interp, Random Urine

Interpretation

Method

High-Performance Liquid Chromatography (HPLC) with Fluorometric Detection

  • Includes quantitation of coproporphyrins, uroporphyrins, and intermediate porphyrins (heptacarboxyl, hexacarboxyl, and pentacarboxyl).
  • Includes liquid chromatography-tandem mass spectrometry (LC-MS/MS) determination of porphobilinogen.
Reference Range
See individual components
Ref. Range Notes

Interpretation: Abnormal results are reported with a detailed interpretation which may include an overview of the results and their significance, a correlation to available clinical information provided with the specimen, differential diagnosis, and recommendations for additional testing when indicated and available.

Interferences and Limitations

Cautions: Porphobilinogen (PBG) and porphyrins are susceptible to degradation at high temperature, at pH below 5.0, and exposure to light.

Neither erythropoietic protoporphyria nor X-linked dominant protoporphyria are detected utilizing urine porphyrins and PBG measurements.

Ethanol and a variety of medications are known to interfere with heme synthesis leading to elevations in urine porphyrins, particularly coproporphyrin. Coproporphyrin elevation without concomitant PBG elevation should not be used as the basis for the diagnosis of porphyria but may warrant follow-up testing with fecal porphyrin analysis.

Ordering & Collection

Specimen Type
Urine
Collection

Collect a random urine sample in a sterile container and protect from light. Expedite transport to the lab.

  • Collect samples Monday - Thursday only to ensure arrival and testing at Mayo within 72 hours of collection.
  • Include a list of the patient's current medications.
Handling Instructions

Outside Laboratories: A timed collection is recommended due to limited sample stability. Random urine specimens must arrive at Mayo Clinic Laboratories within 72 hours of collection.

Quantity
Requested: 20-50 mL urine in light-protected aliquot
Minimum: 15 mL urine in light-protected aliquot

Processing

Receiving Instructions

Aliquot urine into a light-protected (amber) screw-top container.

  • Also Accepted: Aliquot containers wrapped in foil (ensure primary container is properly labeled).

Sendouts:

  • Order Mayo Test: PQNRU.
  • Interfaced: Yes.
  • If provided, list the patient's medications in the "Performing Lab Comments" section of the MayoAccess order.
  • Ensure that the sample is protected from light.
  • Samples must arrive at Mayo within 72 hours of collection.

Stability: Frozen: 72 hours; Refrigerated: Unacceptable; Ambient: Unacceptable.

Misc Sendout

Performance

Lab Department
Sendouts Mayo Lab (FZ)(MAFZ)
Frequency
Performed: Monday - Friday. Report Available: 2-4 days from sample receipt.
Available STAT?
No
Performing Location(s)
Sendout Mayo Clinic Laboratories
800-533-1710

200 First Street Southwest
Rochester, MN 55901

Billing & Coding

CPT Codes
84110, 84120
LOINC
30896-5
Interfaced Order Code
UOW5770