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Test ID: PEE Porphyrins Evaluation, Whole Blood

Reporting Name

Porphyrins Evaluation, WB

Useful For

Establishing a biochemical diagnosis of erythropoietic protoporphyria and X-linked dominant protoporphyria

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
PPFE Protoporphyrins, Fractionation, WB Yes No

Testing Algorithm

This test is recommended for screening patients for possible erythropoietic protoporphyria and X-linked dominant protoporphyria. In addition, it can be used for evaluation of iron-deficiency anemia and chronic lead intoxication. Testing begins with total erythrocyte porphyrins. If the result is below 80 mcg/dL, it is normal, and testing is complete.


If the total erythrocyte porphyrin value is 80 mcg/dL or above, the protoporphyrin fractionation assay will automatically be performed at an additional charge. The fractionation test results include noncomplexed (free) protoporphyrin and zinc-complexed protoporphyrin.


The following algorithms are available:

-Porphyria (Acute) Testing Algorithm 

-Porphyria (Cutaneous) Testing Algorithm 

Specimen Type

Whole blood

Ordering Guidance

This is the preferred test for assessment for protoporphyria. The preferred test for assessing lead toxicity in children is blood lead. For more information see PBDV / Lead, Venous, with Demographics, Blood or PBDC / Lead, Capillary, with Demographics, Blood. The preferred screening test for suspicion of a hepatic porphyria is urine porphyrins. For more information see PQNRU / Porphyrins, Quantitative, Random, Urine.

Necessary Information

Include a list of medications the patient is currently taking.

Specimen Required

All porphyrin tests on whole blood can be performed on 1 collection tube.


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


Preferred: Green top (sodium heparin)

Acceptable: Dark blue top (metal free heparin), green top (lithium heparin), lavender top (EDTA)

Specimen Volume: 4 mL

Collection Instructions: Immediately place specimen on wet ice.

Specimen Minimum Volume

3 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole blood Refrigerated 7 days

Reference Values


<80 mcg/dL

Day(s) Performed

Monday, Wednesday, Friday

Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information


82542-if appropriate

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PEE Porphyrins Evaluation, WB 2814-2


Result ID Test Result Name Result LOINC Value
88886 Total Porphyrins, WB 2814-2
29356 Interpretation 59462-2

Clinical Information

The porphyrias are a group of inherited disorders resulting from enzyme defects in the heme biosynthetic pathway. Depending on the specific enzyme involved, various porphyrins and their precursors accumulate in different specimen types. The patterns of porphyrin accumulation in erythrocytes and plasma and excretion of the heme precursors in urine and feces allow for the detection and differentiation of the porphyrias.


Testing erythrocyte porphyrin level is most informative for patients with a clinical suspicion of erythropoietic protoporphyria (EPP) or X-linked dominant protoporphyria (XLDPP). Clinical presentation of EPP and XLDPP is identical, with onset of symptoms typically occurring in childhood. Cutaneous photosensitivity in sun-exposed areas of the skin generally worsens in the spring and summer months. Common symptoms may include itching, edema, erythema, stinging or burning sensations, and occasionally scarring of the skin in sun-exposed areas. Although genetic in nature, environmental factors can exacerbate symptoms, significantly impacting the severity and course of disease.


EPP is caused by decreased ferrochelatase activity resulting in significantly increased noncomplexed (free) protoporphyrin levels in erythrocytes, plasma, and feces.


XLDPP is caused by gain-of-function variants in the C-terminal end of ALAS2 gene and results in elevated erythrocyte levels of free and zinc-complexed protoporphyrin, and total protoporphyrin levels in plasma and feces.


Protoporphyrin fractionation is the main component of erythrocyte porphyrins. When total erythrocyte porphyrins are elevated, fractionation and quantitation of zinc-complexed and free protoporphyrin is necessary to differentiate the inherited porphyrias from other causes of elevated porphyrin levels. Other possible causes of elevated erythrocyte zinc-complexed protoporphyrin may include:

-Iron-deficiency anemia, the most common cause

-Chronic intoxication by heavy metals (primarily lead) or various organic chemicals

-Congenital erythropoietic porphyria, a rare autosomal recessive porphyria caused by deficient uroporphyrinogen III synthase

-Hepatoerythropoietic porphyria, a rare autosomal recessive porphyria caused by deficient uroporphyrinogen decarboxylase


Typically, the workup of patients with a suspected porphyria is most effective when following a stepwise approach. See Porphyria (Acute) Testing Algorithm and Porphyria (Cutaneous) Testing Algorithm or call 800-533-1710 to discuss testing strategies.


There are 2 test options:

-PEE / Porphyrins Evaluation, Whole Blood

-PEWE / Porphyrins Evaluation, Washed Erythrocytes.

The whole blood option is easiest for clients but requires that the specimen arrive at Mayo Clinic Laboratories within 7 days of collection. When this cannot be ensured, washed frozen erythrocytes, which are stable for 14 days, should be submitted.


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, and recommendations for additional testing when indicated and available.

Clinical Reference

1. Tortorelli S, Kloke K, Raymond K: Disorders of porphyrin metabolism. In: Dietzen DG, Bennett MJ, Wong ECC, eds. Biochemical and Molecular Basis of Pediatric Disease. 4th ed. AACC Press; 2010:307-324

2. Badminton MN, Whatley SD, Schmitt C, Aarsand AK: Porphyrins and the porphyrias. In: Rifai N, Chiu RWK, Young I, Burnham CAD, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:419-419.e32

3. Anderson KE, Sassa S, Bishop DF, Desnick RJ: Disorders of heme biosynthesis: X-linked sideroblastic anemia and the porphyrias In: Valle D, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA, eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill, 2019. Accessed September 1, 2022. Available at

4. Whatley SD, Ducamp S, Gouya B, et al: C-terminal deletions in the ALAS2 gene lead to gain of function and cause X-linked dominant protoporphyria without anemia or iron overload. Am J Hum Genet. 2008 Sep;83(3):408-414

5. Balwani M, Naik H, Anderson KE, et al: Clinical, Biochemical, and Genetic Characterization of North American Patients with Erythropoietic Protoporphyria and X-linked Protoporphyria. JAMA Dermatol. 2017 Aug 1;153(8):789-796

Report Available

3 to 6 days

Method Name


Mayo Clinic Laboratories | Genetics and Pharmacogenomics Catalog Additional Information: