Porphobilinogen Synthase; ALAD Deficiency Porphyria; Doss Porphyria; PBG Synthase
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Aminolevulinic Acid (ALA) Dehydratase, Blood
Test ID: ALAD
Test
Aliases/Synonyms
Method
Enzymatic End point/Spectrofluorometric
Report Includes
ALA Dehydratase; Interpretation
Specimens
Whole Blood (Na Heparin); Whole blood (Li Heparin); Whole blood (EDTA)
Clinical Utility
This assay is not useful in evaluating lead intoxication as it re-activates ALAD that may have been inhibited by lead.
Test Version
30-Sep-2019
Specimen
Specimens
Whole Blood (Na Heparin); Whole blood (Li Heparin); Whole blood (EDTA)
Collection Containers
Preferred
Green top (sodium heparin)
Acceptable
Lavender top (EDTA); Green top (lithium heparin)
Patient Preparation
Patient should abstain from alcohol 24 hours prior to collection.
Collection & Handling
Collection Instructions
Avoid hemolysis
Handling Information
Refrigerate immediately. Submit full tube. Do not freeze. Due to limited stability, sample must be received at ICL from Mon – Wed within 3 days of collection.
Additional Information
Provide a list of current medications.
Stability
| Refrigerated | 4 days |
|---|
Rejection Criteria
| Hemolysis | Visible |
|---|---|
| Other | Ambient or frozen |
Test Version
30-Sep-2019
Performance / Interpretation
Method
Enzymatic End point/Spectrofluorometric
Turnaround Time
7 days
Specimen Retention Time
14 days
Results
| Name | Units | Reference Range | Conversion Factor | |
|---|---|---|---|---|
| Aminolevulinic Acid (ALA) Dehydratase | nmol/L/sec |
|
||
| Interpretation | Abstinence from alcohol is essential for at least 24 hours prior to specimen collection as ethanol suppresses ALAD activity. False-positive values may result from enzyme degradation due to improper specimen handling. It is essential to adhere to collection and handling instructions. | |||
Test Version
30-Sep-2019
Interface / Setup
Test Version
30-Sep-2019