Laboratory: Clinical Biochemistry  (METABOLIC)
Test Name:
PORPHYRINS TOTAL, 24 HOUR, URINE - (U)
Test Code: POR
Clinical Information:
Test Indications: This test is used in the differential diagnosis of porphyria.
 
The porphyrias are a group of inherited disorders resulting from enzyme defects in the heme biosynthetic pathway. Depending on the specific enzyme involved, various porphyrins and their precursors accumulate in different specimen types. The patterns of porphyrin accumulation in erythrocytes and plasma and excretion of the heme precursors in urine and feces allow for the detection and differentiation of the porphyrias.
 
 
If the urine porphyrins screen is positive, quantitation is done as a reflex test.
 
The reflex test includes quantitation of coproporphyrins, uroporphyrins, and intermediate porphyrins (heptacarboxyl, hexacarboxyl, and pentacarboxyl).
 
Porphyrins Screen Method: Spectrophotometry by In-Common Laboratories.
 
Quantitation Method: HPLC by In-Common Laboratories.   
 
For questions/information: Call Metabolic Lab at 204-787-4530 and ask for the Biochemical Geneticist.

Patient Preparation Instructions: Patient should phone the Shared Health Laboratory they would like to go to to get the collection container.  The site will arrange to have the container with appropriate preservative available.
Click here for Shared Health locations 
Collection Devices:
Preferred Device:
1 - Urine Collection Container - 24 h  - Collect 24h urine into an amber container with 5 g sodium carbonate added as a preservative. Keep refrigerated and protected from light during collection.
 
This collection is not suitable for ALA/PBG testing.
Specimen Required:
Urine: 20.0 mL


Adult Urine: 20-50 mL
Specimen pH should be between 7-10. If not, adjust pH immediately by adding sodium carbonate until pH is reached.
 
Store 20-50 mL aliquot frozen and protected from light.
 
Refer to JA110-50-01A
Rejection & Stability: See More Information section below
Referral:

Collection site must confirm specimen pH between 7-10. If not, adjust pH by adding sodium carbonate until pH is reached.
 
Store and ship 20-50 mL aliquot frozen and protected from light to the Metabolic Lab (HSC).

Refer to JA110-50-01A
Rejection & Stability: See More Information section below
Requisition:
Reference Values:
A descriptive report will be sent
Availability:
Within 2 Weeks
See Also:
More Information:
If you have any questions, please communicate with the Metabolic Lab (HSC): 204-787-4530
 
IMPORTANT NOTE: There is no substitution to sodium carbonate to adjust pH.
 
Reject due to: Wrong pH, not preserved with sodium carbonate, sample older than 7 days, not protected from light.
 
Stability: 7 days frozen (light protected)
 
Store and ship frozen (light protected) to In-Common Laboratories.
Test ID: PORPHS U