Appropriate test to rule out acute intermittent porphyria (AIP) and other acute attack types of porphyrias associated with neurologic and/or psychiatric symptoms. Detect porphyrias and porphyrinurias. Acute intermittent porphyria is characterized by excretion of porphobilinogen and δ-aminolevulinic acid in urine during acute attacks but not during latency. Increased porphobilinogen may be caused also by variegate porphyria or hereditary coproporphyria. Increased urine values are seen in the intoxication porphyrias (heavy metals, halogenated solvents, certain drugs).

Screw cap plastic container (non sterile)

On collection of random urine, it is advisable NOT to use first voided morning specimen, late evening specimen after 8 PM, or specimen obtained following excessive fluid intake.

1. Transfer the urine into an Amber screw-cap polypropylene frozen transport tube/vial - 4mL (LabCorp)
   1. If amber tube and cap are not available, cover a clear plastic transport tube COMPLETELY from top to bottom with aluminum foil.
2. If ordered with delta ALA, pH must be < 6.
3. Label the container with the patient's name and date.
4. The specimen should be FROZEN immediately and maintained frozen until tested.

Amber screw-cap polypropylene frozen transport tube/vial - 4mL (LabCorp)

• Specimen exposed to light
• Specimen not received frozen

Chromatography/spectrophotometry

0.0 - 2.0 mg/L