Test Catalog

Test Id : EEEV1

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Red Blood Cell (RBC) Enzyme Evaluation, Blood

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Overview

Test Catalog

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

Identifying defects of red cell enzyme metabolism

 

Evaluating patients with Coombs-negative hemolytic anemia

Profile Information
A profile is a group of laboratory tests that are ordered and performed together under a single Mayo Test ID. Profile information lists the test performed, inclusive of the test fee, when a profile is ordered and includes reporting names and individual availability.

Test Id Reporting Name Available Separately Always Performed
EEEVI Erythrocyte Enzyme Interpretation No Yes
G6PDC G6PD Enzyme Activity, B Yes, Bill Only Yes
PKC PK Enzyme Activity, B Yes, Bill Only Yes
GPIC Glucose Phosphate Isomerase, B Yes, Bill Only Yes
HKC Hexokinase, B Yes, Bill Only Yes
AKC Adenylate Kinase, B Yes, Bill Only Yes
PFKC Phosphofructokinase, B Yes, Bill Only Yes
PGKC Phosphoglycerate Kinase, B Yes, Bill Only Yes
TPIC Triosephosphate Isomerase, B Yes, Bill Only Yes
GSH Glutathione, B Yes Yes
P5NT Pyrimidine 5' Nucleotidase, B Yes Yes

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

This is a consultative evaluation in which the case will be evaluated at Mayo Clinic Laboratories.

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

EEEVI: Medical Interpretation

G6PDC, GPIC, PKC, HKC, AKC, PFKC, PGKC, TPIC, GSH, P5NT: Kinetic Spectrophotometry

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

RBC Enzyme Evaluation

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

RBC Enzymes

Red Cell Enzymes

G6PD

Pyruvate kinase

GPI

Hexokinase

Adenylate kinase

Phosphofructokinase

Triosephosphate isomerase

P5NT

Glutathione

PGK

PFK

AK

HK

Glucose phosphate isomerase

Glucose phosphate dehydrogenase

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

This is a consultative evaluation in which the case will be evaluated at Mayo Clinic Laboratories.

Specimen Type
Describes the specimen type validated for testing

Whole Blood ACD-B

Necessary Information

Metabolic Hematology Patient Information (T810) is strongly recommended and should include clinical history. Testing may proceed without this information, however if the information requested is received, it allows for a more complete interpretation.

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

Container/Tube: Yellow top (ACD solution B)

Specimen Volume: 12 mL

Collection Instructions: Send specimen in original tube. Do not aliquot.

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

Forms

1. Metabolic Hematology Patient Information (T810) is available in Special Instructions.

2. If not ordering electronically, complete, print, and send a Benign Hematology Test Request (T755) with the specimen.

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

5 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 ACD-B Refrigerated (preferred) 11 days

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

Identifying defects of red cell enzyme metabolism

 

Evaluating patients with Coombs-negative hemolytic anemia

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

This is a consultative evaluation in which the case will be evaluated at Mayo Clinic Laboratories.

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

Erythrocyte enzyme deficiencies are inherited causes of hemolytic anemia. Some are very common, such as glucose-6-phosphate dehydrogenase (G6PD) deficiency, and others are very rare, found in only a few families around the world. Most are autosomal, but some are sex-linked and located on the X chromosome. Most enzyme deficiencies result in chronic nonspherocytic hemolytic anemia of variable severity; however, some, such as G6PD, can be hematologically normal with episodic acute hemolysis due to a trigger event such as medications, toxins, or some foods. The RBC enzymopathies do not typically show recurrent pathognomonic changes on the peripheral blood smear other than generic features of hemolytic anemia, although some such as pyruvate kinase deficiency can have echinocytes and pyrimidine 5' nucleotidase (P5NT) deficiency is associated with basophilic stippling. RBC enzyme activity levels are best evaluated as a panel as reticulocytosis can mask some deficient states and comparison to the background enzyme activity is useful.

 

This is a consultative evaluation of red cell enzyme activity as a potential cause of early red cell destruction.

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.

Definitive results and an interpretive report will be provided.

Interpretation
Provides information to assist in interpretation of the test results

A hematopathologist expert in these disorders evaluates the case and an interpretive report is issued.

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

Recent transfusion may mask the patient’s intrinsic enzyme activity and cause unreliable results.

 

A very high white blood cell count can contribute to interference and falsely raise the activity for some enzymes.

 

Some enzyme deficiency disorders can be masked by reticulocytosis and comparison of activities of other RBC enzyme activities in this panel can be useful.

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

1. Koralkova P, van Solinge WW, van Wijk R: Rare hereditary red blood cell enzymopathies associated with hemolytic anemia - pathophysiology, clinical aspects, and laboratory diagnosis. Int J Lab Hematol. 2014 Jun;36(3):388-397

2. Beutler E: Glucose-6-phosphate dehydrogenase deficiency and other enzyme abnormalities. In: Beutler E, Lichtmann MA, Coller BS, Kipps TJ, eds. Hematology. 5th ed. McGraw-Hill Book Company; 1995:564-581

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

Glucose-6-Phosphate Dehydrogenase:

Glucose-6-phosphate dehydrogenase (G6PD) in a hemolysate catalyzes the oxidation of glucose-6-phosphate to 6-phosphogluconate. Concomitantly, nicotinamide adenine dinucleotide phosphate (NADP[+]) is changed to its reduced form (NADPH) and the reaction is measured spectrophotometrically on an automated chemistry analyzer.(Beutler E: Red Cell Metabolism: A Manual of Biochemical Methods. 3rd ed. Grune and Stratton; 1984:68-71; van Solinge WW, van Wijk: Enzymes of the red blood cell. In: Rifai N, Horvath AR, Wittwer CT: eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:chap 30)

 

Pyruvate Kinase:

Pyruvate kinase catalyzes the phosphorylation of adenosine diphosphate (ADP) to adenosine triphosphate (ATP) by converting phosphoenolpyruvate (PEP) to pyruvate. The amount of pyruvate formed is quantitated by adding lactate dehydrogenase and reduced nicotinamide adenine dinucleotide (NADH) and measuring the rate of decrease in absorbance spectrophotometrically at 340 nm as the NADH is oxidized to NAD(+) on an automated chemistry analyzer.(Beutler E: Red Cell Metabolism: A Manual of Biochemical Methods. 3rd ed. Grune and Stratton; 1984:68-71; van Solinge WW, van Wijk: Enzymes of the red blood cell. In: Rifai N, Horvath AR, Wittwer CT: eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:chap 30)

 

Glucose Phosphate Isomerase:

Glucose phosphate isomerase (GPI) interconverts glucose-6-P (G6P) and fructose-6-P (F6P). In this assay, the F6P is then further converted to 6-phosphogluconate (6-PG) through the G6P dehydrogenase (G6PD) reaction resulting in the reduction of NADP(+) to NADPH. The reduction of NADP(+) is measured spectrophotometrically by the increase in absorbance at 340 nm on an automated chemistry analyzer.(Beutler E: Red Cell Metabolism: A Manual of Biochemical Methods. 3rd ed. Grune and Stratton; 1984:40-42; van Solinge WW, van Wijk: Enzymes of the red blood cell. In: Rifai N, Horvath AR, Wittwer CT: eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:chap 30)

 

Hexokinase:

Hexokinase catalyzes the reaction of ATP and glucose to G6P and ADP. In this assay the formation of G6P is measured by linking its further oxidation to 66-PG to the reduction of NADP(+) through the G6PD reaction. The increase in absorbance which occurs as NADP(+) is reduced to NADPH is measured spectrophotometrically at 340 nm on an automated chemistry analyzer.(Beutler E: Red Cell Metabolism: A Manual of Biochemical Methods. 3rd ed. Grune and Stratton;1984:38-40; van Solinge WW, van Wijk: Enzymes of the red blood cell. In: Rifai N, Horvath AR, Wittwer CT: eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:chap 30)

 

Adenlyate Kinase:

Adenylate kinase (myokinase) catalyzes the dismutation of ADP into adenosine-5'-monophosphate (AMP) and ATP. In this assay, the reverse reaction is measured by following the formation of ADP with pyruvate kinase (PK) and lactate dehydrogenase (LDH) reactions resulting in NADH being oxidized to NAD(+). The decrease in absorbance that occurs as NADH is oxidized is measured spectrophotometrically at 340 nm by an automated chemistry analyzer.(Beutler E:  Red Cell Metabolism: A Manual of Biochemical Methods. 3rd ed. Grune and Stratton; 1984:93-95; van Solinge WW, van Wijk: Enzymes of the red blood cell. In: Rifai N, Horvath AR, Wittwer CT: eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:chap 30)

 

Phosphofructokinase:

Phosphofructokinase (PFK) catalyzes the phosphorylation of F6P by ATP to fructose-1,6-diphosphate (FDP). FDP is then converted to dihydroxyacetone phosphate (DHAP) through subsequent aldolase and triosephosphate isomerase (TPI) catalyzed reactions. The rate of formation of DHAP is measured by linking its reduction to alpha-glycerophosphate by alpha-glycerophosphate dehydrogenase, which results in the oxidation of NADH to NAD(+). The decrease in absorbance at 340 nm is measured spectrophotometrically as the NADH is oxidized on an automated chemistry analyzer.(Beutler E: Red Cell Metabolism: A Manual of Biochemical Methods. 3rd ed. Grune and Stratton; 1984:pp 68-71; van Solinge WW, van Wijk: Enzymes of the red blood cell. In: Rifai N, Horvath AR, Wittwer CT: eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:chap 30)

 

Phosphoglycerate Kinase:

Phosphoglycerate kinase (PGK) catalyzes the phosphorylation of ADP to ATP by conversion of 1,3-diphosphoglycerate (1,3-DPG) to 3-phosphoglyceric acid (3-PGA). In this assay, the reaction is driven in the reverse direction. The formation of 1,3-DPG is then measured through the glyceraldehyde phosphate dehydrogenase (GAPD) reaction as 1,3-DPG is converted to glyceraldehyde-3-phosphate (GAP) resulting in the oxidation of NADH to NAD(+). The decrease in absorbance that occurs as NADH is oxidized is measured spectrophotometrically at 340 nm on an automated chemistry analyzer.(Beutler E: Red Cell Metabolism: A Manual of Biochemical Methods. 3rd ed. Grune and Stratton; 1984, pp 53-55; van Solinge WW, van Wijk: Enzymes of the red blood cell. In: Rifai N, Horvath AR, Wittwer CT: eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:chap 30)

 

Triosephosphate Isomerase: 

Triosephosphate isomerase (TPI) interconverts glyceraldehyde-3-phosphate (GAP) and DHAP. The rate of DHAP formation is measured by further converting it to alpha-glycerophosphate by alpha-glycerophosphate dehydrogenase, which results in the oxidation of NADH to NAD(+).The decrease in absorbance that occurs as NADH is oxidized is measured spectrophotometrically at 340 nm on an automated chemistry analyzer.(Beutler E: Red Cell Metabolism: A Manual of Biochemical Methods. Grune and Stratton1984; van Solinge WW, van Wijk: Enzymes of the red blood cell. In: Rifai N, Horvath AR, Wittwer CT: eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:chap 30)

 

Glutathione:

Virtually all of the nonprotein sulfhydryl of red cells is in the form of reduced glutathione (GSH). 5,5'-dithiobis (2-nitrobenzoic acid) is a disulfide compound that is readily reduced by sulfhydryl compounds, forming a highly colored yellow anion. The absorbance of this resultant yellow substance is measured by 412 nm and compared to that of a known standard.(Beutler E: Red Cell Metabolism: A Manual of Biochemical Methods. 3rd ed. Grune and Stratton; 1984; Alisik M, Neselioglu S, Erel O: A colorimetric method to measure oxidized, reduced and total glutathione levels in erythrocytes. J Lab Med. 2019:43(5), 269-277. doi: 10.1515/labmed-2019-0098)

 

Pyrimidine 5’ Nucleotidase:

Pyrimidine nucleotides have a spectral absorption curve that is markedly different from that exhibited by (normally present) adenine nucleotides, eg, ATP. The former have a peak at about 270 nm; the latter at about 257 nm. Thus, pyrimidine 5' nucleotidase deficiency may be ascertained by demonstrating a very high spectral absorption maximum of 270 nm in erythrocyte extracts.(Beutler E: Red Cell Metabolism: A Manual of Biochemical Methods. 3rd ed. Grune and Stratton; 1984:100-102; van Solinge WW, van Wijk: Enzymes of the red blood cell. In: Rifai N, Horvath AR, Wittwer CT: eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:chap 30)

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 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.

2 to 13 days

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

14 days

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.

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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.

82955-G6PD Enzyme Activity

84087-Glucose phosphate isomerase

84220-Pyruvate Kinase Enzyme Activity

82657-Hexokinase

82657-Adenylate Kinase

82657-Phosphofructokinase

82657-Phosphoglycerate Kinase

82657-Triosephosphate Isomerase

82978-Glutathione

83915-Pyrimidine 5’ Nucleotidase

LOINC® Information

Test Id Test Order Name Order LOINC Value
EEEV1 RBC Enzyme Evaluation 72695-0
Result Id Test Result Name Result LOINC Value
Result LOINC Value Tooltip

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