Porphobilinogen and Aminolevulinic Acid, Plasma
Use
This test is useful as an equivalent to urine for the first-line evaluation of suspected acute porphyria, particularly when a urine specimen cannot be obtained during a symptomatic episode. It is also used to monitor patients undergoing treatment for acute intermittent porphyria or other acute porphyrias. Plasma porphobilinogen and aminolevulinic acid levels are elevated during the symptomatic phase of acute porphyrias such as acute intermittent porphyria, hereditary coproporphyria, and variegate porphyria. Isolated elevation of aminolevulinic acid may indicate ALA dehydratase deficiency porphyria or secondary inhibition of ALA dehydratase.
Special Instructions
Specimen collection should occur during acute phase when symptoms are present for most informative results. Specimens must be refrigerated or frozen in amber vials to protect from light. Alcohol consumption should be avoided for at least 24 hours prior to specimen collection.
Limitations
Additional testing is necessary to distinguish among the different types of acute porphyrias. Therapy or improper sample handling may decrease detectable levels of porphobilinogen and aminolevulinic acid. Exposure of specimens to light and high temperatures will degrade porphobilinogen. Therefore, specimens should be protected from light immediately after collection.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 96911-3
- 17474-8
- 79646-6
- 59462-2
- 18771-6
Result Turnaround Time
3-9 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
0.3 mL
Container
Amber vial
Collection Instructions
Collect during acute phase. Centrifuge and aliquot plasma into plastic vial.
Patient Preparation
Do not consume alcohol for at least 24 hours prior to specimen collection.
Storage Instructions
Ship specimens refrigerated or frozen and in amber vial to protect from light.
Causes for Rejection
Exposure to light or improper storage.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 7 days |
| Frozen | 21 days |