Porphobilinogen, Quantitative, 24-Hour Urine
Test Summary
Urinary Porphobilinogen is the first step in the diagnosis of acute porphyria's 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.
Aliases
- N/A
Specimen Collection
Special Instructions
N/A
Preferred Specimen
2 mL from 24-hour urine containing sodium carbonate collected in a plastic leak-proof container - protect from light
Minimum Volume
1 mL
Instructions
24-hour urine, collection should be adjusted to a pH of 6-7 with 5g sodium carbonate (Na2CO3). Add the sodium carbonate at the start of the collection. The urine should be refrigerated and protected from light during collection.
Whenever possible, the specimen should be collected during an acute episode because porphobilinogen (PBG) may decrease rapidly upon remission. PBG may also degrade when samples are exposed to UV light for extended periods, or are transported at ambient temperature. If an amber collection jug/urine cup is not available, the sample must be protected from light by completely wrapping the container in aluminum foil. Twenty-four hour specimens should be refrigerated and protected from UV light during collection. PBG is most stable at pH 6-7, but samples may be sent with or without preservative. All results should be interpreted in the context of clinical findings, relevant history, and other laboratory data.
Whenever possible, the specimen should be collected during an acute episode because porphobilinogen (PBG) may decrease rapidly upon remission. PBG may also degrade when samples are exposed to UV light for extended periods, or are transported at ambient temperature. If an amber collection jug/urine cup is not available, the sample must be protected from light by completely wrapping the container in aluminum foil. Twenty-four hour specimens should be refrigerated and protected from UV light during collection. PBG is most stable at pH 6-7, but samples may be sent with or without preservative. All results should be interpreted in the context of clinical findings, relevant history, and other laboratory data.
Patient Preparation
N/A
Storage
N/A
Transport Temperature
Refrigerated (cold packs)
Specimen Stability
- Room temperature: Unacceptable
- Refrigerated: 7 days
- Frozen: 30 days
Limitations
N/A
Other Acceptable Specimens
N/A
Unacceptable Specimens
Not protected from light
Order Code
PORPBN
EPIC (Premier) Code
LAB328
Includes
CPT code 81050 may be added at an additional charge for volume measurement
CPT Code
- 84110
Billing Code
- 670427
CPT Statement
Methodology
Chromatography/Mass Spectrometry
FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by the U.S. Food and Drug Administration. The FDA has determined that such clearance or approval is not necessary. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Physician Attestation of Informed Consent
N/A
Testing Laboratory
Quest Diagnostics Nichols Institute
33608 Ortega Highway
San Juan Capistrano CA, 92675
33608 Ortega Highway
San Juan Capistrano CA, 92675
Department
Reference Testing
Reference Range
| ≤17 Years | Not established |
| ≥18 Years | <0.34 mg/24 h |
Setup Schedule / Expected Turnaround Time
Tuesday, Thursday, Saturday; Report available: 4 - 7 days
Specimen Collection
Special Instructions
N/A
Preferred Specimen
2 mL from 24-hour urine containing sodium carbonate collected in a plastic leak-proof container - protect from light
Minimum Volume
1 mL
Instructions
24-hour urine, collection should be adjusted to a pH of 6-7 with 5g sodium carbonate (Na2CO3). Add the sodium carbonate at the start of the collection. The urine should be refrigerated and protected from light during collection.
Whenever possible, the specimen should be collected during an acute episode because porphobilinogen (PBG) may decrease rapidly upon remission. PBG may also degrade when samples are exposed to UV light for extended periods, or are transported at ambient temperature. If an amber collection jug/urine cup is not available, the sample must be protected from light by completely wrapping the container in aluminum foil. Twenty-four hour specimens should be refrigerated and protected from UV light during collection. PBG is most stable at pH 6-7, but samples may be sent with or without preservative. All results should be interpreted in the context of clinical findings, relevant history, and other laboratory data.
Whenever possible, the specimen should be collected during an acute episode because porphobilinogen (PBG) may decrease rapidly upon remission. PBG may also degrade when samples are exposed to UV light for extended periods, or are transported at ambient temperature. If an amber collection jug/urine cup is not available, the sample must be protected from light by completely wrapping the container in aluminum foil. Twenty-four hour specimens should be refrigerated and protected from UV light during collection. PBG is most stable at pH 6-7, but samples may be sent with or without preservative. All results should be interpreted in the context of clinical findings, relevant history, and other laboratory data.
Patient Preparation
N/A
Storage
N/A
Transport Temperature
Refrigerated (cold packs)
Specimen Stability
- Room temperature: Unacceptable
- Refrigerated: 7 days
- Frozen: 30 days
Limitations
N/A
Other Acceptable Specimens
N/A
Unacceptable Specimens
Not protected from light
Result Information
Methodology
Chromatography/Mass Spectrometry
Testing Laboratory
N/A
Reference Range
| ≤17 Years | Not established |
| ≥18 Years | <0.34 mg/24 h |
Setup Schedule / Expected Turnaround Time
Tuesday, Thursday, Saturday; Report available: 4 - 7 days