Test Catalog

Test Id : PEE

Porphyrins Evaluation, Whole Blood

Useful For
Suggests clinical disorders or settings where the test may be helpful

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

Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.

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

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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 

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Name
A short description of the method used to perform the test

Spectrofluorometric

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Porphyrins Evaluation, WB

Aliases
Lists additional common names for a test, as an aid in searching

Erythrocyte Porphyrin

Erythropoietic Protoporphyria (EPP)

Free Erythrocyte Porphyrin (FEP)

Protoporphyrin

Protoporphyrins, Total, Erythrocytes

RBC Porphyrins

Red Blood Cell Porphyrins

X-linked Dominant Protoporphyria (XLDPP, XLEPP, or XDP)

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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
Describes the specimen type validated for testing

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
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

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.

Container/Tube:

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.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Forms

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

3 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Whole blood Refrigerated (preferred) 7 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

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

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

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 

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

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.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

PORPHYRINS, TOTAL, RBC

<80 mcg/dL

Interpretation
Provides information to assist in interpretation of the test results

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.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Alcohol suppresses enzyme activity potentially leading to false-positive results if it is ingested within 24 hours of specimen collection.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

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 https://ommbid.mhmedical.com/content.aspx?sectionid=225540906&bookid=2709

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

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Method Description
Describes how the test is performed and provides a method-specific reference

This evaluation is performed as a 2-step analysis. First, the total red blood cell (RBC) porphyrin concentration is determined by extracting the porphyrins from washed, resuspended RBCs using a mixture of ethyl acetate and acetic acid. The porphyrins are then back extracted into dilute hydrochloric acid. Total porphyrins are quantified using this extract via spectrofluorometry.(Piomelli S: Free erythrocyte porphyrins in the detection of undue absorption of Pb and Fe deficiency. Clin Chem. 1977;23:264-269; Gou EE, Balwani M, Bissell DM, et al: Pitfalls in erythrocyte protoporphyrin measurement for diagnosis and monitoring of protoporphyrias. Clin Chem. 2015 Dec;61[12]:1453-1456. doi: 10.1373/clinchem.2015.245456)

 

If the total porphyrin concentration is elevated, the RBCs are re-extracted to separate and quantify the zinc-complexed and noncomplexed (free) protoporphyrin via high-performance liquid chromatography.(Smith RM, Doran D, Mazur M, Bush B: High-performance liquid chromatographic determination of protoporphyrin and zinc protoporphyrin in blood. J Chromatogr. 1980 Mar 14;181[3-4]:319-327; Gou EE, Balwani M, Bissell DM, et al: Pitfalls in erythrocyte protoporphyrin measurement for diagnosis and monitoring of protoporphyrias. Clin Chem. 2015 Dec;61[12]:1453-1456. doi: 10.1373/clinchem.2015.245456)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday, Wednesday, Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

3 to 6 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

Residual whole blood, processed specimen: 2 weeks

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

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
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

84311

82542-if appropriate

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
PEE Porphyrins Evaluation, WB 2814-2
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
88886 Total Porphyrins, WB 2814-2
29356 Interpretation 59462-2

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports