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Order Code LABGOR, PQNRU Porphyrins, Quantitative, Random, Urine

Additional Codes

Mayo Test Code: PQRU

Reporting Name

Porphyrins, QN, Random, U

Useful For

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 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 random urine test should be ordered when the specimen will reach Mayo Clinic Laboratories within 72 hours. If transportation will take longer than 72 hours, order PQNU / Porphyrins, Quantitative, 24 Hour, Urine and follow collection guidelines.



Shipping Instructions


Ship specimen in amber bottle to protect from light.



Necessary Information


Include a list of medications the patient is currently taking.



Specimen Required


Patient Preparation: Patient should not consume any alcohol for the 24 hours before specimen collection.

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

Container/Tube: Amber, 60-mL urine container

Specimen Volume: 20 to 50 mL

Collection Instructions: Collect a random urine specimen.


Specimen Minimum Volume

15 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Frozen 72 hours LIGHT PROTECTED

Reference Values

Uroporphyrins, Octacarboxyl:

≤30 nmol/L

 

Heptacarboxylporphyrins:

≤7 nmol/L

 

Hexacarboxylporphyrins:

≤2 nmol/L

 

Pentacarboxyporphyrins:

≤5 nmol/L

 

Copropprphyrin, Tetracboxyl:

≤110 nmol/L

 

Porphobilinogen:

≤1.3 mcmol/L

Day(s) Performed

Monday through Friday

CPT Code Information

84110-Porphobilinogen, quantitative

84120-Porphyrins, quantitation and fractionation

Genetics Test Information

This test is preferred test during symptomatic periods for acute intermittent porphyria, hereditary coproporphyria, and variegate porphyria. The random urine collection for this test allows for the diagnosis to be established and treatment to be initiated quickly. However, this test should only be ordered when the specimen will be received at Mayo Clinic Laboratories within 72 hours of collection. If it will be longer, PQNU / Porphyrins, Quantitative, 24 Hour, Urine should be ordered and collection guidelines must be followed.

 

Testing includes porphobilinogen which is useful in the evaluation of the acute porphyrias.

 

This is the preferred test to begin assessment for congenital erythropoietic porphyria and porphyria cutanea tarda.

Method Description

An aliquot of urine is acidified and mesoporphyrin is added as an injection marker. Porphyrins in the acidified urine are separated by high-performance liquid chromatography, and the eluted porphyrins are quantified by comparison of their fluorescence intensity to that of known porphyrin standards.(Ford RE, Ou CN, Ellefson RD. Liquid chromatographic analysis for urinary porphyrins. Clin Chem. 1981;27[3]:397-401; de Andrade VL, Mateus ML, Aschner M, Dos Santos AM. Assessment of occupational exposures to multiple metals with urinary porphyrin profiles. J Integr OMICS. 2018;8(1):216. doi:10.5584/jiomics.v8i1.216)

 

Porphobilinogen 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;47[9]:1627-1632; Louleb M, Galvan I, Latrous L, et al. Detection of porphyrins in hair using capillary liquid chromatography-mass spectrometry. Int J Mol Sci. 2022;23[11]:6230. doi:10.3390/ijms23116230)

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)