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Test Code UPORM Porphyrins, Quantitative, 24 Hour, Urine

Additional Codes

 

 

MAYO Test ID

PQNU

EPIC Test ID

LAB433

 

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 (if the specimen will be received at Mayo Medical Laboratories within 72 hours of collection, PQNRU / Porphyrins, Quantitative, Random, Urine is recommended)

Testing Algorithm

The following algorithms are available in Special Instructions: 

-Porphyria (Acute) Testing Algorithm

-Porphyria (Cutaneous) Testing Algorithm

Method Name

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.

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type

Urine


Necessary Information


1. 24-Hour volume is required.

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

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



Specimen Required


Patient Preparation: Patient should abstain from alcohol for 24 hours prior to, as well as during, collection.

Supplies:

Amber, 60-mL urine bottle (T596)

Sodium Carbonate, 5 gram (T272)

Specimen Volume: 20-50 mL

Collection Instructions:

1. Collect a 24-hour urine specimen.

2. Add 5 g of sodium carbonate (T272) as preservative at start of collection. This preservative is intended to achieve a pH of >7. Do not substitute sodium bicarbonate for sodium carbonate.

3. The container should be refrigerated and protected from light as much as possible during collection. An aliquot should be frozen when collection is complete.

4. Protect specimen from light.

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


Specimen Minimum Volume

15 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Frozen 7 days

Reject Due To

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

Specimen not protected from light, pH <5.0

Reference Values

UROPORPHYRINS (OCTACARBOXYL)

≤30 nmol/24 hours

 

HEPTACARBOXYLPORPHYRINS

≤9 nmol/24 hours

 

HEXACARBOXYLPORPHYRINS

≤8 nmol/24 hours

 

PENTACARBOXYLPORPHYRINS

≤10 nmol/24 hours

 

COPROPORPHYRINS (TETRACARBOXYL)

Males: ≤230 nmol/24 hours

Females: ≤168 nmol/24 hours

 

PORPHOBILINOGEN

≤2.2 mcmol/24 hours

Day(s) and Time(s) Performed

Monday through Friday; 7 a.m.

CPT Code Information

84110-Porphobilinogen, quantitative

84120-Porphyrins, quantitation and fractionation

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PQNU Porphyrins, QN, U In Process

 

Result ID Test Result Name Result LOINC Value
TM3 Collection Duration 13362-9
VL1 Urine Volume 3167-4
29357 Uroporphyrin, Octa 15096-1
29358 Heptacarboxylporphyrins 25434-2
29359 Hexacarboxylporphyrins 25438-3
29360 Pentacarboxylporphyrins 25494-6
29361 Coproporphyrin, Tetra 15041-7
29362 Porphobilinogen 14882-5
23403 Interpretation 59462-2

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

Analytic Time

2 days (not reported on Saturday or Sunday)

Urine Preservative Collection Options

Ambient

No

Refrigerate

No

Frozen

No

6N HCl

No

50% Acetic Acid

No

Na2CO3

Required**

Toluene

No

6N HNO3

No

Boric Acid

No

Thymol

No

**Protect specimen from light.