Porphobilinogen levels in the urine should be measured during acute attacks of abdominal pain, extremity pain or paresthesias, tachycardia, nausea and vomiting, neurologic abnormalities, and to investigate dark urine.
It is an initial test for acute intermittent porphyria, which is characterized by urinary excretion of porphobilinogen and δ-aminolevulinic acid during acute attacks. Increased urinary excretion of porphobilinogen may be caused also by acute attacks of variegate porphyria or of hereditary coproporphyria, and also in lead poisoning (rarely). In lead poisoning, urinary δ-aminolevulinic acid measurement is more useful.
Frozen (preferred) - 1 month
Refrigerated - 24 hours
Porphobilinogen,Qn,U: 0.1 mg/L 0.0 − 2.0
Porphobilinogen, 24U: 0.2 mg/24 hr 0.0 − 1.5