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Test ID NBLD0078 Porphyrins, Quantitative, 24 Hour, Urine

Reporting Name

Porphyrins, QN, U

Useful For

Preferred screening test 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 be longer than 72 hours

 

This test is not useful for the diagnosis of conjugated or unconjugated hyperbilirubinemia syndromes such as Dubin Johnson syndrome or Rotor syndrome

Testing Algorithm

The following algorithms are available:

-Porphyria (Acute) Testing Algorithm

-Porphyria (Cutaneous) Testing Algorithm

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Urine


Ordering Guidance


This 24-hour urine test should be ordered when the specimen will not be received at Mayo Clinic Laboratories (MCL) within 72 hours. If the specimen will be received at MCL within 72 hours, order PQNRU / Porphyrins, Quantitative, Random, Urine.



Shipping Instructions


Ship specimen in amber container to protect from light.



Necessary Information


1. 24-Hour volume (in milliliters) is required.

2. Patient's sex is required.

3. Collection date and time should be documented upon completion of the 24-hour collection.

4. Include a list of medications the patient is currently taking.



Specimen Required


Patient Preparation: For the 24 hours before, as well as during, specimen collection, patient must not consume any alcohol.

Supplies:

-Urine Container - Amber, 60-mL (T596)

-Sodium Carbonate, 5 gram (T272)

Container/Tube: 60-mL Amber urine container

Specimen Volume: 20 to 50 mL

Collection Instructions:

1. Add 5 g of sodium carbonate as preservative at start of collection. This preservative is intended to achieve a pH above 7. Do not substitute sodium bicarbonate for sodium carbonate.

2. Collect a 24-hour urine specimen.

3. The container should be refrigerated and protected from light as much as possible during collection.

4. Record volume and duration.

5. Aliquot 20 to 50 mL into an amber container and freeze.

Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.


Specimen Minimum Volume

15 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Frozen 7 days LIGHT PROTECTED

Reference Values

Uroporphyrins, Octa: ≤30 nmol/24 h

Heptacarboxylporphyrins: ≤9 nmol/24 h

Hexacarboxylporphyrins: ≤8 nmol/24 h

Pentacarboxylporphyrins: ≤10 nmol/24 h

Coproporphyrin, Tetra:

Males: ≤230 nmol/24 h

Females: ≤168 nmol/24 h

Porphobilinogen: ≤2.2 mcmol/24 h

Day(s) Performed

Monday through Friday

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-Porphobilinogen, quantitative

84120-Porphyrins, quantitation and fractionation

Report Available

2 to 4 days

Reject Due To

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Method Name

High-Performance Liquid Chromatography (HPLC) with Fluorometric Detection/Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Urine Preservative Collection Options

Note: Preservative must be added before beginning collection.

Ambient (no additive)

No

Refrigerate (no additive)

No

Frozen (no additive)

No

50% Acetic Acid

No

Boric Acid

No

Diazolidinyl Urea

No

6M Hydrochloric Acid

No

6M Nitric Acid

No

Sodium Carbonate

Required

Toluene

No

**Protect specimen from light.