Test Directory

• Coproporphyrin I
• Coproporphyrin III
• Heptacarboxyporphyrin
• Hexacarboxyporphyrin
• Pentacarboxyporphyrin
• Uroporphyrin I
• Uroporphyrin III
• Total Porphyrins

Urinary Porphobilinogen is the first step in the diagnosis of acute porphyrias such as acute intermittent porphyria (AIP). AIP is an autosomal dominant disorder characterized by deficiency of porphobilinogen deaminase. An acute attack usually includes gastrointestinal disturbance and neuropsychiatric disorders.

Specimen Type: 24 Hour Urine Protected from Light

Collection Container: 24 Hour Plastic Urine Container containing sodium carbonate 

Desired Specimen Volume: 4 mL

1. Collect 24-hour urine in a jug containing sodium carbonate.
2. The urine should be refrigerated and protected from UV light during collection.

1. Transfer 4 mL of urine to an amber aliquot tube (screw cap). Protect from light.
2. If an amber aliquot tube is not available, completely wrap the specimen and cap with aluminum foil.

Whenever possible, the specimen should be collected during an acute episode because porphobilinogen (PBG) may decrease rapidly upon remission. 

Transport to the laboratory frozen.

• Not protected from light
• pH <4.0 (acidified urine)

 See patient report.

All results should be interpreted in the context of clinical findings, relevant history, and other laboratory data.

PBG may degrade when samples are exposed to UV light for extended periods, or are transported at ambient temperature.

•  Porphyrins, Fractionated, Quantitative and Porphobilinogen, 24-Hour Urine