87351:PORPHYRINS, QUANTITATIVE, 24-HOUR URINE

Print View Attached Docs:
87351:PORPHYRINS, QUANTITATIVE, 24-HOUR URINE
Alias Names: AIP / CEP / HCP / PGB / PCT / VP
Methodology: High Performance Liquid Chromatography (HPLC) with Fluorometric Detection
Edit Date: 11/16/2010
Performed: Monday-Friday
Released: 72 hours after setup at PeaceHealth Laboratories’ reference lab.
CPT Code: 84120-90
Specimen Collection Details
Collection: 24-hour urine with 5 gm of sodium carbonate (Na2CO3) added as a preservative (no substitutes) at the start of collection to achieve a pH of >7.0. Container should be refrigerated and protected from light as much as possible during collection and storage. Patient should abstain from alcohol for 24 hours prior to and during collection.
Handling: Aliquot 50 mL urine into a clean, dry plastic container. Freeze. Protect from light. pH should be 7.0 or greater. Indicate total collection volume on requisition.
Stability: 24 hours refrigerated or 30 days frozen. Unstable ambient.
Standard Volume: 50 mL urine aliquot.
Minimum Volume: 20 mL urine aliquot.
Transport: Frozen on dry ice.
Comments: If specimen was collected without preservative at start of collection, order Porphyrins, Urine (80620) and/or Porphobilinogen (PBG) (93440).
Rejection Criteria: Sodium bicarbonate or preservative other than sodium carbonate; other than a 24-hour collection; total collection volume not indicated on requisition.

Porphyrins
Uroporphyrins (octacarboxyl) 3-25 µg/24 hours
Heptacarboxylporphyrins 0-7 µg/24 hours
Hexacarboxylporphyrins 0-6 µg/24 hours
Pentacarobxylporphyrins 0-7 µg/24 hours
Porphobilinogen 0.0-0.5 µg/24 hours
Coproporphyrins (tetracarboxyl)
Males 25-150 µg/24 hours
Females 8-110 µg/24 hours
The measurement of PBG in urine is important in the diagnosis of acute, neurologic porphyrias including acute intermittent porphyria (AIP), hereditary coproporphyria (HCP), and variegate porphyria (VP). Urinary porphyrin determination is helpful in the diagnosis of these disorders, as well as other porphyrias including congenital erythropoietic porphyria (CEP) and porphyria cutanea tarda (PCT).