Porphyrins, Quantitative, 24-Hour Urine

Also known as: Coproporphyrin, Uroporphyrin

Clinical Use

Use

Evaluate porphyrias, including those involving deficiencies of enzymes that are needed for heme synthesis and chemical porphyrias.

Special Instructions

Not provided.

Limitations

Increased porphobilinogen can be present in patients using oral contraceptives, potentially affecting results. This test, along with δ-aminolevulinic acid, might not detect protoporphyria. Coproporphyrinuria lacks sensitivity and specificity for detecting lead poisoning. Erythrocyte uroporphyrinogen-1-synthase activity decrease is associated with latent acute intermittent porphyria and is not detectable with this test. The test might miss some cases of latent acute intermittent porphyria compared to red cell uroporphyrinogen-1-synthase activity measurement.

Test Details

Methodology

Other

Biomarkers

6 targets

Coproporphyrin (CP) ICoproporphyrin (CP) IIIHeptacarboxylporphyrins (7-CP)Hexacarboxylporphyrins (6-CP)Pentacarboxylporphyrins (5-CP)Uroporphyrins (UP)

LOINC Codes

Order Codes

43116-3 - Porphyrin Fract Pnl 24h Ur

Result Codes

47253-0 - Copro1 24h Ur-mCnc
6877-5 - Copro1 24h Ur-mRate
47254-8 - Copro3 24h Ur-mCnc
6878-3 - Copro3 24h Ur-mRate
11228-4 - Uropor Ur-mCnc
3113-8 - Uropor 24h Ur-mRate
2407-5 - Hepta-CP Ur-mCnc
24462-4 - Hepta-CP 24h Ur-mRate
27400-1 - Hexa-CP Ur-mCnc
9527-3 - Hexa-CP 24h Ur-mRate
11221-9 - Penta-CP Ur-mCnc
9730-3 - Penta-CP 24h Ur-mRate

Result Turnaround Time

3-7 days

Specimen

Urine

Volume

2-mL aliquot

Minimum Volume

1.5-mL aliquot

Container

12-mL plastic transport tube without preservative

Collection Instructions

Instruct patient to void at 8 AM (or 8 PM) and discard the specimen. Then collect all the urine including the final specimen voided at the end of the 24-hour collection period (8 AM [or 8 PM] the following day). Mix well. Measure, record total urine volume on the test request form, along with the patient's name, date, and time collection started and finished. Transfer required aliquot into a LabCorp amber plastic transport tube with amber cap (LabCorp N° 23598). If 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.