Porphyrin Profile, Plasma (Sendout)

Useful For: Monitoring treatment of patients with porphyria cutanea tarda.

Test Information:

• Plasma specimens from patients with active porphyria cutanea tarda, congenital erythropoietic porphyria, and erythropoietic protoporphyria may exhibit increased plasma porphyrin levels. However, a definitive diagnosis cannot be made by plasma analysis alone.
• Plasma porphyrins are most appropriate for monitoring patients being treated for porphyria cutanea tarda.
• Analysis of plasma porphyrins is suitable for individuals with bullous dermatosis who are in kidney failure and unable to provide a urine specimen.

Test Algorithm: If total porphyrins are above 1.0 mcg/dL, then Porphyrins, Fraction, Plasma (Sendout) [RPORPF] will be performed at an additional charge.

• Porphyria (Acute) Testing Algorithm
• Porphyria (Cutaneous) Testing Algorithm

Patient Preparation: Patient should abstain from alcohol for at least 24 hours prior to specimen collection.

Ordering Requirements: Include a list of medications the patient is currently taking in the Epic order comment.

Porphyrins, Total: Extraction and Scanning Spectrofluorometry

Porphyrins, Fractionation: High-Performance Liquid Chromatography (HPLC)

Interpretation: Abnormal results are reported with a detailed interpretation that may include an overview of the results and their significance, a correlation to available clinical information provided with the specimen, differential diagnosis, recommendations for additional testing when indicated and available, and a phone number to reach one of the laboratory directors in case the referring physician has additional questions.

10 mL GREEN TOP tube (Na Heparin or Lithium Heparin without gel) protected from light (wrap in foil after collection)

Also Accepted: LAVENDER TOP (EDTA) tube, protected from light

Unacceptable: Lime Green PST/Gel tubes

Outside Laboratories:

• Centrifuge sample and transfer plasma to a separate amber/light-protected vial.
  • If an amber aliquot tube is not available, the sample may be wrapped in foil, but both the primary container and the foil must be properly labeled with patient information.
• Freeze plasma at -20°C while awaiting shipment.
• Transport on dry ice.

Stability: Frozen (required): 14 days; Refrigerated: Unacceptable; Ambient: Unacceptable.

Reject Due To: Sample not light-protected.

Centrifuge sample and transfer plasma into an amber plastic aliquot tube (Mayo Supply T915) to protect from light. Freeze plasma at -20°C.

Sendouts:

• Order Mayo Test: PTP
• Interfaced: Yes [Interface: 601; Worksheet: MAFZ]

Stability: Frozen (required): 14 days; Refrigerated: Unacceptable; Ambient: Unacceptable.

Reject Due To: Sample not light-protected.