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Porphyrins, Quantitative, Random Urine

CPT: 84120
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  • Coproporphyrin
  • Uroporphyrin

Test Includes

Coproporphyrins I and III; uroporphyrins; hepatocarboxylporphyrins; hexacarboxylporphyrins; pentacarboxylporphyrins

Expected Turnaround Time

3 - 5 days

Related Documents

Specimen Requirements


Urine (random); protected from light


2 mL

Minimum Volume

1.5 mL


12-mL amber plastic transport tube without preservative


Transfer required aliquot into a LabCorp amber plastic transport tube with amber cap (LabCorp N° 23598). (If amber transport tubes are unavailable, cover transport tube completely, top and bottom, with aluminum foil. Identify specimen with patient's name directly on the amber transport tube and on the outside of the aluminum foil. Secure with tape.) Specimen must be kept refrigerated during transport.

Storage Instructions

Refrigerate and protect from light.

Stability Requirements



Room temperature



7 days


14 days

Freeze/thaw cycles

Stable x3

Causes for Rejection

Stored specimen not refrigerated; specimen exposed to light; acid preservative; pH <3

Test Details


Urine porphyrins are useful for the evaluation of cutaneous photosensitivity to exclude porphyria cutanea tarda (PCT). Evaluation of neurologic and/or psychiatric symptoms associated with acute porphyrias, such as acute intermittent porphyria (AIP), requires urine porphobilinogen (PBG) testing. Refer to Porphobilinogen (PBG), Quantitative, Random Urine [003053].

For initial evaluation of porphyrias. Use Porphyrins, Quantitative, 24-Hour Urine [003194] to follow up random urine abnormal results.


High-pressure liquid chromatography (HPLC) with fluorometric detection

Reference Interval

• Coproporphyrin (CP) I: 0−15 μg/L

• Coproporphyrin (CP) III: 0−49 μg/L

• Heptacarboxylporphyrins (7-CP): 0−2 μg/L

• Hexacarboxylporphyrins (6-CP): 0−1 μg/L

• Pentacarboxylporphyrins (5-CP): 0−2 μg/L

• Uroporphyrins (UP): 0−20 μg/L

Additional Information

Excess urinary porphyrin excretion, or porphyrinuria, results from inhibition of key enzymatic steps in such clinical conditions as genetic deficiencies in heme production enzymes, hepatitis, renal disease, and erythroid disease, as well as by heavy metal inhibition of heme enzyme synthesis.1 Both in experimental animals and in humans exposed to heavy metals, elevated levels of porphyrins have been found in urine.1


1. Woods JS. Altered porphyrin metabolism as a biomarker of mercury exposure and toxicity. Can J Physiol Pharmacol. 1996 Feb; 74(2):210-215.8723034


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
120980 Porphyrins, Qn, Random U 120988 Uroporphyrins (UP) ug/L 11228-4
120980 Porphyrins, Qn, Random U 120989 Heptacarboxyl (7-CP) ug/L 2407-5
120980 Porphyrins, Qn, Random U 120990 Hexacarboxyl (6-CP) ug/L 27400-1
120980 Porphyrins, Qn, Random U 120991 Pentacarboxyl (5-CP) ug/L 11221-9
120980 Porphyrins, Qn, Random U 120992 Coproporphyrin (CP) I ug/L 9343-5
120980 Porphyrins, Qn, Random U 120993 Coproporphyrin (CP) III ug/L 9345-0

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