Porphobilinogen
DefinitionThis section has been translated automatically.
Porphobilinogen (PBG) is a metabolic product of the hem biosynthesis. The main sites of synthesis are the liver and the bone marrow. PBG is formed from δ-aminolevulinic acid by the cytosolic ALS-dehydratase (PBG-synthase).
LaboratoryThis section has been translated automatically.
- Light protected storage in brown collection containers without additives for 24 hour urine.
- Standard value: 400 - 1.200 µg/l in urine
- Elevated levels are found in chronic liver damage, alcoholism, oral contraceptives and drug-induced liver damage, among others.
- Confounding factors: Phenothiazines: falsely elevated values.
DiagnosisThis section has been translated automatically.
Diagnosis or exclusion of acute hepatic porphyria and differential diagnostic evaluation of other forms of porphyria in one profile, especially acute intermittent porphyria [AIP], hereditary coproporphyria [HK] and porphyria variegata [PV].
Note(s)This section has been translated automatically.
- The PBG excreted in the urine in acute hepatic porphyrias originates from the liver. The porphobilinogen test is used in the context of immediate diagnosis to detect or exclude acute hepatic porphyria (so-called Hösch test; see also porphyrins). The evaluation of PBG excretion can only be performed within the framework of a diagnostic profile of the metabolites of heme synthesis (see porphyria below).
- Influencing factors: Increases are possible in chronic liver damage, alcoholism, oral contraceptives and drug-induced liver damage.