Test Id : PPFWE
Protoporphyrins, Fractionation, Washed Erythrocytes
Useful For
Suggests clinical disorders or settings where the test may be helpful
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
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
This test should not be ordered in conjunction with PEWE / Porphyrins Evaluation, Washed Erythrocytes.
The following algorithms are available:
-Porphyria (Acute) Testing Algorithm
Method Name
A short description of the method used to perform the test
High-Performance Liquid Chromatography (HPLC) with Fluorescence Detection
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
EPP (Erythropoietic Protoporphyria)
Erythropoietic Protoporphyria
Free Protoporphyrin
Zinc Protoporphyrin
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 should not be ordered in conjunction with PEWE / Porphyrins Evaluation, Washed Erythrocytes.
The following algorithms are available:
-Porphyria (Acute) Testing Algorithm
Specimen Type
Describes the specimen type validated for testing
Washed RBC
Ordering Guidance
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 specimen (red cells + saline) are required and must be sent with specimen.
2. Include a list of medications the patient is currently taking.
ORDER QUESTIONS AND ANSWERS
| Question ID | Description | Answers |
|---|---|---|
| BG571 | Total cell suspension | |
| BG572 | Packed cell volume |
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
All porphyrin tests on erythrocytes can be performed on 1 tube.
Patient Preparation: Patient must not consume any alcohol for 24 hours before specimen collection.
Collection Container/Tube:
Preferred: Green top (sodium heparin)
Acceptable: Dark blue top (metal free heparin), green top (lithium heparin), or lavender top (EDTA)
Submission Container/Tube: Plastic vial
Specimen Volume: Entire 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 at 4 degrees C 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.
Special Instructions
Library of PDFs including pertinent information and forms related to the test
Forms
If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
1 mL of washed and resuspended erythrocytes
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Cell suspension not available | 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 |
|---|---|---|---|
| Washed RBC | Frozen (preferred) | 14 days | |
| Refrigerated | 14 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
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
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
This test should not be ordered in conjunction with PEWE / Porphyrins Evaluation, Washed Erythrocytes.
The following algorithms are available:
-Porphyria (Acute) 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 protoporphyrin fractions 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 exacerbate symptoms, significantly impacting the severity and course of disease.
Erythropoietic protoporphyria is caused by diminished ferrochelatase resulting in significantly increased free protoporphyrin levels in erythrocytes, plasma, and feces.
X-linked dominant protoporphyria 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 in plasma and feces.
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:
-PPFE / Protoporphyrins, Fractionation, Whole Blood
-PPFWE / Protoporphyrins, Fractionation, 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.
FREE PROTOPORPHYRIN
<20 mcg/dL
ZINC-COMPLEXED PROTOPORPHYRIN
<60 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
Patients must abstain from alcohol for at least 24 hours prior to specimen collection. Alcohol suppresses enzyme activity potentially leading to false-positive results.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Tortorelli S, Kloke K, Raymond K. Disorders of porphyrin metabolism. In: Dietzen DJ, Bennett MJ, Wong EDD, eds. Biochemical and Molecular Basis of Pediatric Disease. 4th ed. AACC Press; 2010:307-324
2. Phillips JD: Heme biosynthesis and the porphyrias. Mol Genet Metab. 2019;128(3):164-177. doi:10.1016/j.ymgme.2019.04.008
3. Anderson KE, Sassa S, Bishop DF, Desnick RJ. Disorders of heme biosynthesis: X-Linked sideroblastic anemia and the porphyrias. In: Valle DL, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA, eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; 2019. Accessed September 6, 2024. Available at https://ommbid.mhmedical.com/content.aspx?sectionid=225540906&bookid=2709
4. Whatley SD, Ducamp S, Gouya L, et al. C-terminal 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;83(3):408-414
Method Description
Describes how the test is performed and provides a method-specific reference
Extraction followed by fractionation by high-performance liquid chromatography. Zinc protoporphyrin and free protoporphyrin are separately quantitated.(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]:1453-6. doi:10.1373/clinchem.2015.245456)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
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 through 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.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
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 account representative. 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. It 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.
CPT codes are provided by the performing laboratory.
82542
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 |
|---|---|---|
| PPFWE | Protoporphyrins, Fractionation, RBC | 94490-0 |
| 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.
|
|---|---|---|
| 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 |