Lab Test

Aminolevulinic Acid, 24 Hour Urine

ALA (Aminolevulinic Acid), DALA (Delta-Aminolevulinic Acid), AIP (Acute Intermittent Porphyria), ALA Dehydratase Deficiency Porphyria (ADP), HCP (Hereditary Coproporphyria), VP (Variegate Porphyria)

Test Codes

EPIC: LAB6747, Beaker: XALUA, Mayo: FALAU

Department

Send Outs

Instructions

Specimen Collection Criteria

Collect (preferred specimen):  24-hour urine sample with no preservative. Keep 24-hour urine specimen iced or refrigerated during collection.

  • Include start and end dates and times for the collection period on the specimen container.
Urine Preservative Options
No Preservative
6N Hydrochloric Acid
Boric Acid (10g)
Sodium Carbonate
50% Acetic Acid
REQUIRED
Unacceptable
Unacceptable
Unacceptable
Unacceptable

Physician Office/Draw Specimen Preparation

Maintain specimens refrigerated (2-8°C or 36-46°F) prior to transport

Preparation for Courier Transport

Transport: Entire 24-hour urine collection, refrigerated (2-8°C or 36-46°F)

Rejection Criteria

Specimens not collected and processed as indicated. 

In-Lab Processing

Measure total volume of 24-hour urine specimen. Record total volume and collection start and end dates and times in the LIS system. Aliquot 4.0 mL from the well-mixed 24-hour urine collection and transfer to a transport tube. (Minimum: 1.2 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): Unacceptable
Refrigerated (2-8°C or 36-46°F): 4 days
Frozen (-20°C/-4°F or below): 30 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Mayo Clinic Laboratories in Rochester, MN. Forwarded to ARUP Laboratories, Salt Lake City, UT.

Performed

Monday, Wednesday, Friday.
Results available within 2-9 days

Reference Range

By report.

Test Methodology

Quantitative Ion Exchange Chromatography / Spectrophotometry.

Interpretation

  • Slight elevations of ALA may be seen in association with exposure to alcohol, lead, and a variety of other agents. Significant elevations are often associated with the acute porphyrias (massive elevations of porphobilinogen, PBG). Significant elevations are also seen in hereditary tyrosinemia.
  • Specimen preservation with acid or base is discouraged and may cause assay interference. When collecting the urine for additional tests that require acid or base preservation, the ALA aliquot should be taken prior to the addition of the acid or base.
  • Aminolevulinic acid (ALA) dehydratase is poisoned by heavy metals, such as lead and mercury, so that ALA accumulates, and excess amounts appear in the urine.
  • In children, measurement of urinary ALA is more sensitive than measurement of blood lead for evaluation of lead poisoning.
  • ALA excretion may also be increased in congenital hepatic porphyria.
  • ALA may be elevated in hereditary tyrosinemia and late pregnancy.

Clinical Utility

The ALA assay aids in the diagnosis of a form of acute intermittent porphyria or an induction/toxic porphyria. This assay indicates lead intoxication in children.

CPT Codes

82135
LOINC:  34284-0, 14689-4

Contacts

Last Updated

12/16/2022

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