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Test Code LAB9565 Porphyrins, Quantitative, Random, Urine

Additional Codes

PQNRU

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 both PQNU / Porphyrins, Quantitative, 24 Hour, Urine and ALAUR / Aminolevulinic Acid, 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 must  not consume any alcohol for at least 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:

1. Collect a random urine specimen.

2. No preservative necessary but pH must be above 5.0. If pH is below 5.0, specimen will be rejected.

3. Specimens should be protected from light and frozen immediately following collection.


Specimen Minimum Volume

15 mL

Specimen Stability Information

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

Reference Values

Uroporphyrins, Octacarboxyl:

≤3.1 mcmol/mol creatinine

 

Heptacarboxylporphyrins:

≤0.9 mcmol/mol creatinine

 

Hexacarboxylporphyrins:

≤0.3 mcmol/mol creainine

 

Pentacarboxyporphyrins:

≤1.2 mcmol/mol creatinine

 

Coproporphyrin, Tetra::

≤25.0 mcmol/mol creatinine

 

Porphobilinogen:

≤0.2 mmol/mol creatinine

 

Aminolevulinic Acid

≤ 2.3 mmol/mol creatinine

Day(s) Performed

Monday through Friday

CPT Code Information

84110-Porphobilinogen, quantitative

84120-Porphyrins, quantitation and fractionation

82135- ALA Delta Random Urine

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PQNRU Porphyrins, QN, Random, U 93707-8

 

Result ID Test Result Name Result LOINC Value
32332 Uroporphyrin, Octa 25166-0
32333 Heptacarboxylporphyrins 34314-5
32334 Hexacarboxylporphyrins 96795-0
32335 Pentacarboxylporphyrins 34352-5
32336 Coproporphyrin, Tetra 25167-8
32337 Porphobilinogen 2811-8
623039 Aminolevulinic Acid, U 39782-8
32338 Interpretation 49291-8
623040 Reviewed By 18771-6

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.

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)

 

Aminolevulinic acid (ALA) is determined by liquid chromatography tandem mass spectrometry (LC-MS/MS) stable isotope dilution analysis. The urine is mixed with an internal standard ([13]C5, [15]N ALA-IS) and filtered using a 0.2 mcM nylon filter vial. The ratios of the extracted peak areas of ALA to ALA-IS determined by LC-MS/MS are used to calculate the concentration of ALA present in the sample.(Lacey, JM, Magera MJ, Tortorelli S: Delta aminolevulinic acid quantitation in urine by LC-MS/MS. J Am Soc Mass Spectrom. 2011;22, S1:pp 69)

Report Available

2 to 4 days

Specimen Retention Time

1 week

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)

Secondary ID

60597