Test Overview
Clinical Utility
This assay is not useful in evaluating lead intoxication as it re-activates ALAD that may have been inhibited by lead.
Method
Spectrofluorometry - enzymatic end point
Result Included
ALA Dehydratase; Interpretation
Aliases/Synonyms
Porphobilinogen Synthase; ALAD Deficiency Porphyria; Doss Porphyria; PBG Synthase
Specimen
Specimen Type
Whole Blood (Na Heparin)Whole blood (Li Heparin)
Whole blood (EDTA)
Containers
Preferred Containers
Green top (sodium heparin)
Acceptable Containers
Lavender top (EDTA); Green top (lithium heparin)
Volume
Minimum Volume
3 mL
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
| Criteria | Specification |
|---|---|
| Hemolysis | Visible |
| Other | Ambient or frozen |
Performance & Interpretation
Turnaround Time
7 days
Specimen Retention Time
14 days
Results
-
Aminolevulinic Acid (ALA) Dehydratasenmol/L/sec≥4.0
Indeterminate 3.5 - 3.9
Diminished <3.5
This assay is not useful in evaluating lead intoxication as it re-activates ALAD that may have been inhibited by lead. -
InterpretationAbnormal results are reported with a detailed interpretation including an overview of the results and their significance, a correlation to available clinical information provided with the specimen, differential diagnosis, and recommendations for additional testing when indicated and available
Comment
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.
Referral Location
Out-of-Country
Test Version
Last Updated
2019-09-30