Uroporphyrinogen Decarboxylase, Washed Erythrocytes
Use
Diagnosis of porphyria cutanea tarda type II and hepatoerythropoietic porphyria. Uroporphyrinogen decarboxylase is deficient in cases of type II porphyria cutanea tarda (PCT), which can be diagnosed through enzyme analysis. However, this test is uninformative in sporadic PCT cases. All forms of PCT and HEP present cutaneous photosensitivity and scarring on sun-exposed surfaces due to accumulation of uroporphyrin and intermediary carboxyl porphyrins.
Special Instructions
Include a list of medications the patient is currently taking. Patient must not consume any alcohol for 24 hours before specimen collection, as alcohol suppresses enzyme activity. Follow the Porphyria (Cutaneous) Testing Algorithm for effective diagnosis.
Limitations
Alcohol ingestion within 24 hours of specimen collection may lead to a false-positive result. Exposure to significant heat may decrease enzyme activity, affecting results.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 49596-0
- 49596-0
- 59462-2
- 18771-6
Result Turnaround Time
3-9 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
Entire washed erythrocyte suspension
Minimum Volume
1 mL of washed and resuspended erythrocytes
Container
Plastic vial
Collection Instructions
Transfer entire specimen to a 12-mL graduated centrifuge tube. Centrifuge at 4 degrees C for 10 minutes at 2000 rpm. Record volume of packed cells and total volume. Discard supernatant plasma. Wash erythrocytes 2 times with 5 mL of cold 0.9% saline, discarding supernatant after each wash. Resuspend packed cells to original volume with 0.9% saline.
Patient Preparation
Patient must not consume any alcohol for 24 hours before specimen collection.
Causes for Rejection
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 4 days |
| Refrigerated | 14 days |
| Frozen | 14 days |