Porphyrins & Porphobilinogen
Label Mnemonic: PBGPU
Epic Lab Code: LAB7365
Downtime Form: A-1a Miscellaneous Request
Commercial Mail-out Laboratory
5231 RCP
356-8593
Specimen(s):
Urine (24 hr or random) More information
Specimen Instructions:
Refrigerate during 24 hr collection in dark plastic container. The most important aspect of specimen preservation is adequate refrigeration during collection, storage, and transport. Protect from light during collection, storage, and shipment. Record total volume and collection time interval on transport tube and test request form.
Collection Medium:
Urine - 24 hour/timed dark plastic urine container
Minimum:
24 hr collection in dark plastic container and refrigerate during entire collection and submission to University of Iowa Hospitals and Clinics laboratory. Containers available from Pharmacy.

24 hr collection or random urine
  Preferred Minimum:  8 mL aliquot of urine
  Absolute Minimum:  4 mL aliquot or urine
Rejection Criteria:
Body fluids other than urine.
Turn Around Time:
2-5 days upon receipt at reference laboratory
Reference Range:
Components: Reference Interval: Uroporphyrin 0-4 μ mol/mol crt Heptacarboxylate 0-2 μ mol/mol crt Porphyrin Coproporphyrin I 0-6 μ mol/mol crt Coproporphyrin III 0-14 μ mol/mol crt Porphobilinogen, Urine 0.0-8.8 μ mol/L Porphobilinogen, 0.0-11.0 μ mol/d Urine (24-hour) Creatinine (24-hour) Male (mg/d) Female (mg/d) 3-8 yrs: 140-700 3-8 yrs: 140-700 9-12 yrs: 300-1300 9-12 yrs: 300-1300 13-17 yrs: 500-2300 13-17 yrs: 400-1600 18-50 yrs: 1000-2500 18-50 yrs: 700-1600 51-80 yrs: 800-2100 51-80 yrs: 500-1400 81+ yrs: 600-2000 81+ yrs: 400-1300 Note: 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).
Interpretive Data:
Results are normalized to creatinine concentration and reported as a ratio of amounts (micromoles of porphyrin/moles of creatinine).
Comments:
Submit collection dates and times on requisition. Includes Uroporphyrins, Heptacarboxylporphyrins, Coproporphyrins, Porphobilinogens, and Creatinine value. Protect from strong light; refrigerate during collection. The most important aspect of specimen preparation is adequate refrigeration during collection, storage, and transport. Samples collected according to refrigerated guidelines are viable for 4 days ONLY refrigerated.
Test Limitations:
Urine porphyrins are useful for the evaluation of cutaneous photosensitivity to exclude porphyria cutanea tarda (PCT). Evaluation of neurologic and/or psychiatric symptoms associated with acute porphyrias such as acute intermittent porphyria (AIP) requires urine porphobilinogen (PBG) testing.
Methodology:
High Performance Liquid Chromatography/Ion Exchange Chromatography/ Quantitative Spectrophotometry
CPT Code:
84120 Porphyrins, urine; 84110 PBG, urine
 
See also:
Aminolevulinic Acid, Urine (24 hour or random)
Porphobilinogen, Qualitative, Urine, Random