ARUP's Laboratory Test Directory

Erythrocyte Porphyrin (EP), Whole Blood : 0020610

Mnemonic: FEP

Methodology: Fluorometry
Performed: Mon, Wed, Sat
Reported: 1-4 days
Specimen Required: Collect: Royal blue (EDTA), lavender (EDTA), or pink (K2EDTA). Use royal blue tube when also testing for lead.

Specimen Preparation: Protect from light within one hour of collection and during storage and shipment. Transfer 1 mL whole blood to an ARUP Amber Transport Tube. (Min: 0.5 mL)

Storage/Transport Temperature: Refrigerated.

Remarks: Specimen should be tested for lead FIRST to avoid potential contamination problems. Specimens not protected from light acceptable with a disclaimer.

Unacceptable Conditions: Specimens not collected in EDTA. Clotted specimens.

Stability (collection to initiation of testing): Ambient: Unacceptable; Refrigerated: 2 weeks; Frozen: 1 month
Reference Interval:
0-35 µg/dL
Note: Elevated EP results are seen in early and late iron deficiency, in the anemia of chronic disease, and in chronic lead poisoning (typically when blood lead is greater than 25 µg/dL).  Elevated protoporphyrin (as in erythropoietic protoporphyria) and zinc coproporphyrin (usually associated with childbirth) can increase the apparent EP signal. A more specific test for free protoporphyrin is Porphyrins, Serum Total (0080429).  Specimens which are hemolyzed, clotted, or improperly aliquoted may show false elevations.
CPT Code(s): 84202
Cross References: FEP (Erythrocyte Porphyrin (EP), Whole Blood), Porphyrins (FEP) (Erythrocyte Porphyrin (EP), Whole Blood), Protoporphyrin, Free Erythrocyte (FEP) (Erythrocyte Porphyrin (EP), Whole Blood)