Monitor porphyria cutanea tarda (PCT). Confirm diagnosis of suspected variegate porphyria (VP) and erythropoietic protoporphyria (EPP).
Sun, Tue, Thu
Green (heparin), lavender (EDTA), or plain red
CRITICAL: Protect from light during collection, storage, and shipment. Separate plasma or serum from cells within 1 hour of collection. Transfer 2 mL plasma or serum to an ARUP Amber Transport Tube. (Min: 1 mL)
Body fluids other than plasma or serum. Frozen whole blood. Hemolyzed specimens.
After separation from cells: Ambient: Unacceptable; Refrigerated: 4 days; Frozen: 1 month
Useful for evaluation of cutaneous photosensitivity to rule out porphyrin disorders, particularly erythropoietic protoporphyria. Urine is the best specimen for evaluation of suspected porphyria cutanea tarda (PCT), but monitoring of PCT with plasma or serum is an acceptable practice. Evaluation of neurologic and/or psychiatric symptoms associated with suspected acute porphyria (such as acute intermittent porphyria) requires Porphobilinogen (PBG), Urine (ARUP test code 0080260).
Specimens from patients with suspected erythropoietic protoporphyria should be carefully protected from exposure to light.
Protoporphyrin is extremely light sensitive, whereas uroporphyrin and coproporphyrin are much less sensitive.
|Component Test Code*||Component Chart Name||LOINC|
|0080433||Porphyrins, Total, Plasma/Serum||33311-2|
|0084037||Porphyrins, Total, Plasma/Serum, Interp.||14883-3|
- Variegate Porphyria Porphyrin
- VP Porphyrin