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Order Code LABPEWE Porphyrins Evaluation, Whole Blood

Additional Codes

Mayo Test Code: PEE

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 

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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 must not consume any alcohol for 24 hours before 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.


Specimen Minimum Volume

3 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole blood Refrigerated 7 days

Reference Values

PORPHYRINS, TOTAL, RBC

<80 mcg/dL

Day(s) Performed

Monday through Friday

CPT Code Information

84311

82542-if appropriate

Method Description

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;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;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;61[12]:1453-1456. doi:10.1373/clinchem.2015.245456)

Reject Due To

Gross hemolysis Reject

Method Name

Spectrofluorometric