What is porphyria screen?
To diagnose porphyrias, laboratories measure porphyrins and their precursors in urine, blood, and/or stool. Testing may include measurement of one or more of the following: Porphobilinogen (PBG), a porphyrin precursor, in urine. Delta-aminolevulinic acid (ALA), another porphyrin precursor, in urine.
What is Porphobilinogen urine test?
Porphobilinogen (PBG) is measured in patients with symptoms that suggest acute intermittent porphyria, variegate porphyria, or hereditary coproporphyria.
Is Porphobilinogen a porphyrin?
Urine porphyrins are useful for the evaluation of cutaneous photosensitivity to exclude porphyria cutanea tarda (PCT). Urine porphobilinogen (PBG) is useful for the evaluation of neurologic and/or psychiatric symptoms to exclude acute porphyrias such as acute intermittent porphyria (AIP).
What is porphyrins in urine?
Porphyrins are natural chemicals in the body that help form many important substances in the body. One of these is hemoglobin, the protein in red blood cells that carries oxygen in the blood. Porphyrins can be measured in the urine or blood.
Where can you find coproporphyrin 3 in urine?
Coproporphyrin III is a porphyrin derivative. Small amounts of porphyrins (coproporphyrin) are excreted in normal human urine. Coproporphyrin also is present in bile and feces.
Can a coproporphyrin test detect protoporphyria?
The accompanying flow diagrams outline steps for the investigation of cutaneous and neurologic porphyrias. Increased porphobilinogen may occur in patients on oral contraceptives. This test and δ-aminolevulinic acid will not detect protoporphyria. Coproporphyrinuria alone lacks specificity and sensitivity for lead testing.
Is there a link between porphyrin and coproporphyrinuria?
Ann Clin Biochem. 1990 Sep; 27 (Pt 5):395-412. Increased urine porphyrin excretion may be secondary to other diseases (eg, hepatobiliary diseases), especially coproporphyrin excretion. These are secondary porphyrinurias.
Can a great increase in coproporphyrin III be misdiagnosed?
A great increase of coproporphyrin III excretion is unaccompanied by symptoms or signs of porphyria, metal or chemical poisoning or liver disease. If acute porphyria, which is often misdiagnosed, is suspected, please discuss further steps with your healthcare professional.
