Porphobilinogen/Creatinine Ratio, Urine — Turbidimetry
A quantitative urine test that measures porphobilinogen relative to creatinine, helping evaluate porphyrin precursor excretion during suspected acute porphyria.
["An elevated PBG-to-creatinine ratio can support a diagnosis of acute porphyria, especially when compatible symptoms are present."]
Key facts at a glance
- LOINC
- 108510-9
- Short code
- PBG/Creat Msmt Ur
- Synonyms
- PBG/Creat Msmt Ur
- Category
- kidney
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test measures porphobilinogen (PBG), a substance produced during heme production, in urine. The result may be expressed relative to urine creatinine, which helps account for differences in urine concentration.
Why might I need this test?
A urine PBG test may be ordered when severe abdominal pain, weakness, confusion, seizures, or other symptoms raise concern for an acute porphyria attack. It may also be used to monitor people with a known or suspected porphyria.
How is the test performed?
A urine specimen is collected and analyzed in the laboratory. The laboratory quantifies PBG and may use urine creatinine to calculate a concentration-adjusted PBG result.
How do I prepare for the test?
Follow the collection instructions provided by your healthcare professional, including whether a timed or 24-hour collection is required. Label the container with the collection time and store or transport it as directed.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated PBG result or PBG-to-creatinine ratio may indicate increased porphyrin precursor production, as can occur during an acute porphyria attack. Results should be interpreted with symptoms, medication history, and other laboratory findings because isolated abnormalities do not establish the diagnosis. A result that is not elevated may make an active acute porphyria attack less likely, but repeat or alternative testing may sometimes be needed.
Short name
Urine PBG/Creatinine Ratio
Frequently asked questions
What does an elevated urine PBG level mean?
Why is creatinine included in the result?
Do I need to collect a 24-hour urine sample?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy