Ordering Recommendation

Essential first-line test for suspected acute porphyria in adults. Use in determining metabolic response to IV hematin.

New York DOH Approval Status

Testing is not New York state approved. Specimens from New York clients will be sent out to a New York state-approved laboratory.

Specimen Required

Patient Preparation

Random or 24-hour urine. Refrigerate 24-hour specimens during collection.

Specimen Preparation

Protect from light. Transfer 2 mL aliquot from a random or well-mixed 24-hour collection to ARUP amber transport tubes. (Min: 1.5 mL) Record total volume and collection time interval on transport tube and test request form.

Storage/Transport Temperature


Unacceptable Conditions

Body fluids other than urine.


Ambient: Unacceptable; Refrigerated: 1 week; Frozen: 1 month


Quantitative High Performance Liquid Chromatography-Tandem Mass Spectrometry




1-5 days

Reference Interval

Test Number
Reference Interval
  Creatinine, Urine - per 24h
Male (mg/d)
Female (mg/d)
3-8 years 140-700 140-700
9-12 years 300-1300 300-1300
13-17 years 500-2300 400-1600
18-50 years 1000-2500 700-1600
51-80 years 800-2100 500-1400
81 years and older 600-2000 400-1300

  Porphobilinogen, Urine - per 24h 0.4 - 1.5 µmol/d
  Porphobilinogen, Urine - ratio to CRT 0.0 - 0.2 mmol/mol CRT

Interpretive Data

Porphobilinogen (PBG), Urine

Results for random urine specimens are normalized to creatinine (CRT) concentration and reported as a ratio of amounts (millimoles of PBG/mole of creatinine).

Porphobilinogen (PBG) in a random urine specimen is used to evaluate an attack of acute porphyria. Slight increases in urinary PBG are associated with acute porphyrias other than acute intermittent porphyria (AIP) and may indicate a resolving or treated acute porphyria.

Urinary PBG in excess of two times the upper reference limit is consistent with acute porphyria.

Per 24h calculations are provided to aid interpretation for collections with a duration of 24 hours and an average daily urine volume. For specimens with notable deviations in collection time or volume, ratios of analytes to a corresponding urine creatinine concentration may assist in result interpretation.

Compliance Category

Laboratory Developed Test (LDT)


Appropriate test to rule out acute intermittent porphyria (AIP) and other acute attack types of porphyrias associated with neurologic and/or psychiatric symptoms.

Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
0020207 Creatinine, Urine - per volume 2161-8
0020208 Creatinine, Urine - per 24h 2162-6
0080261 Porphobilinogen, Urine - per 24h 14882-5
0080262 Porphobilinogen (PBG), Urine -per volume 2811-8
0097110 Total Volume 19153-6
0097111 Hours Collected 30211-7
3017599 Porphobilinogen, Urine - ratio to CRT
3017600 Porphobilinogen Interpretation
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Acute Porphyria Screening Test
  • PBG, Quantitative Porphobilinogen
Porphobilinogen (PBG), Urine