Sign in →

Test Code PPFWE Protoporphyrins, Fractionation, Washed Erythrocytes

Reporting Name

Protoporphyrins, Fractionation, RBC

Useful For

Preferred test for analysis of erythrocyte protoporphyrin fractions

 

Preferred test for evaluating patients with possible diagnoses of erythropoietic protoporphyria and X-linked dominant protoporphyria

 

Establishing a biochemical diagnosis of erythropoietic protoporphyria, or X-linked dominant protoporphyria

Testing Algorithm

This test should not be ordered in conjunction with PEWE / Porphyrins Evaluation, Washed Erythrocytes.

 

The following algorithms are available in Special Instructions:

-Porphyria (Acute) Testing Algorithm

-Porphyria (Cutaneous) Testing Algorithm

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Washed RBC


Advisory Information


This test is for assessment for protoporphyria, an erythropoietic porphyria. The preferred test for 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


1. Volume of packed cells and total volume of erythrocyte suspension (red cells + saline) are required and must be sent with specimen.

2. Include a list of medications the patient is currently taking.



Specimen Required


All porphyrin tests on erythrocytes can be performed on 1 tube.

 

Patient Preparation: Patient should abstain from alcohol for 24 hours.

Collection Container/Tube:

Preferred: Green top (sodium heparin)

Acceptable: Dark blue top (metal free heparin) or green top (lithium heparin)

Submission Container/Tube: Plastic vial

Specimen Volume: Washed erythrocyte suspension

Collection Instructions: Collect and process whole blood specimen as follows:

1. Transfer entire specimen to a 12-mL graduated centrifuge tube.

2. Centrifuge specimen for 10 minutes at 2000 rpm.

3. Record volume of packed cells and the total volume of the specimen.

4. Discard supernatant plasma.

5. Wash packed erythrocytes 2 times by resuspension of at least an equal amount of cold 0.9% saline, mix, and centrifuge for 5 minutes at 2000 rpm, discarding supernatant after each washing.

6. Resuspend packed cells to the original total volume with 0.9% saline. Invert specimen gently to mix.

7. Transfer washed erythrocytes into a plastic vial and freeze.


Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Washed RBC Frozen (preferred) 14 days
  Refrigerated  14 days

Reference Values

FREE PROTOPORPHYRIN

<20 mcg/dL

 

ZINC-COMPLEXED PROTOPORPHYRIN

<60 mcg/dL

Day(s) and Time(s) Performed

Wednesday; 10:30 a.m.

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 U.S. Food and Drug Administration.

CPT Code Information

82542

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PPFWE Protoporphyrins, Fractionation, RBC 94490-0

 

Result ID Test Result Name Result LOINC Value
31932 Zinc-Complexed Protoporphyrin 2895-1
31933 Free Protoporphyrin 94491-8
INTP6 Interpretation 59462-2
BG571 Total cell suspension 94496-7
BG572 Packed cell volume 94497-5

Method Name

High-Performance Liquid Chromatography (HPLC) with Fluorescence Detection

Forms

If not ordering electronically, complete, print, and send an Inborn Errors of Metabolism Test Request (T798) with the specimen.