Home
HelpTest Code LAB131324 Porphyrins, Quantitative, 24 Hour, Urine
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Reporting Name
Porphyrins, QN, USpecimen Type
UrineOrdering 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.
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Frozen | 7 days | LIGHT PROTECTED |
Specimen Minimum Volume
15 mL
Special Instructions
Day(s) Performed
Monday through Friday
Specimen Retention Time
1 weekReport Available
2 to 4 daysReference 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
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
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 | 43116-3 |
| 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 |
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 (PBG) 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, Chezick PA, Fauq A, McConnell JP. 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)
Disease States
- Porphyria
Genetics Test Information
This test is preferred 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 Clinic Laboratories within 72 hours of collection, PQNRU / Porphyrins, Quantitative, Random, Urine is recommended.
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.
Forms
If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.