Sign in →

Test ID: REVE1 Erythrocytosis Evaluation, Whole Blood


Advisory Information


Polycythemia vera and acquired causes of erythrocytosis should be excluded before ordering this evaluation.



Shipping Instructions


All 3 specimens must arrive within 72 hours of collection.



Necessary Information


Include recent transfusion information.

 

Include most recent complete blood cell count results.

 

Metabolic Hematology Patient Information (T810) is strongly recommended and should include clinical history, erythropoietin (EPO) levels, and JAK2 results, if known. Testing may proceed without this information, however if the information requested is received, it allows for a more complete interpretation.



Specimen Required


A total of 3 specimens are required to perform this profile. The following specimens are required for testing:

-Whole blood EDTA

-Whole blood sodium heparin for P50*

-Normal shipping control: Whole blood sodium heparin for P50*

*Please note: If no sodium heparin patient or control specimens are received, the P50 test cannot be performed.

 

Patient:

Container/Tube: Lavender top (EDTA) and green top (heparin)

Specimen Volume:

EDTA: 5 mL

Heparin: 4 mL

Collection Instructions:

1. Immediately refrigerate specimens after collection.

2. Send specimen in original tube. Do not aliquot.

3. Rubber band patient specimen and control vial together.

 

Normal Shipping Control:

Container/Tube: Green top (heparin)

Specimen Volume: 4 mL

Collection Instructions:

1. Collect a control specimen from a normal (healthy), unrelated, nonsmoking person at the same time as the patient.

2. Label clearly on outermost label normal control.

3. Immediately refrigerate specimen after collection.

4. Send specimen in original tube. Do not aliquot.

5. Rubber band patient specimen and control vial together.


Forms

1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826)

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

Useful For

Definitive, comprehensive, and economical evaluation of an individual with JAK2-negative erythrocytosis associated with lifelong sustained increased hemoglobin or hematocrit

Profile Information

Test ID Reporting Name Available Separately Always Performed
REVEI Erythrocytosis Interpretation No Yes
HGBCE Hb Variant, A2 and F Quantitation,B Yes Yes
HPLC HPLC Hb Variant, B No Yes
P50P Oxygen Dissociation P50 No Yes
CTRL P50 Shipping Control Vial No Yes
MASS Hb Variant by Mass Spec, B No Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
SDEX Sickle Solubility, B Yes No
HEMP Hereditary Erythrocytosis Mut, B Yes No
IEF Isoelectric Focusing, B No No
UNHB Hb Stability, B No No
HPFH Hb F Distribution, B No No
ATHAL Alpha-Globin Gene Analysis Yes No
WASQR Alpha Globin Gene Sequencing, B Yes, (Order WASEQ) No
WBSQR Beta Globin Gene Sequencing, B Yes, (Order WBSEQ) No
WBDDR Beta Globin Cluster Locus Del/Dup,B Yes, (Order WBDD) No
WGSQR Gamma Globin Full Gene Sequencing No No
BPGMM BPGM Full Gene Sequencing Yes No
VHLE VHL Gene Erythrocytosis Mutations Yes, (Order VHLZ) No
REVE0 Erythrocytosis Summary Interp No No

Testing Algorithm

This is a consultative evaluation in which the case will be evaluated at Mayo Clinic Laboratories, the appropriate tests performed at an additional charge, and the results interpreted.

 

This profile evaluates for hereditary (congenital) causes of erythrocytosis. Symptoms should be long-standing or familial in nature. All cases will be tested for p50 (if shipping control is received) and hemoglobin variants (cation exchange high performance liquid chromatography (HPLC), capillary electrophoresis and mass spectrometry) with an interpretative report. Additional testing is guided in a reflexive manner, and may include molecular testing of the HBA1/HBA2, HBB, EPOR, VHL, EGLN1(PHD2), EPAS1(HIF2a), and BPGM genes, among others, as appropriate. See Erythrocytosis Evaluation Testing Algorithm in Special Instructions.

 

An additional consultative interpretation that summarizes all testing, will be provided after test completion to incorporate subsequent results into an overall evaluation if any of the following molecular tests are reflexed:

-ATHAL / Alpha-Globin Gene Analysis, Varies

-WASQR / Alpha Globin Gene Sequencing, Blood

-WBSQR / Beta-Globin Gene Sequencing, Blood

-WBDDR / Beta-Globin Cluster Locus Deletion/Duplication, Blood

-WGSQR / Gamma-Globin Full Gene Sequencing, Varies

-BPGMM / 2,3-Bisphosphoglycerate Mutase, Full Gene Sequencing Analysis, Varies

-HEMP / Hereditary Erythrocytosis Mutations, Whole Blood

-VHLE / VHL Gene, Erythrocytosis Mutation Analysis, Varies

 

The following algorithms are available in Special Instructions:

-Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation

-Myeloproliferative Neoplasm: A Diagnostic Approach to Peripheral Blood Evaluation

 

See Benign Hematology Evaluation Comparison in Special Instructions

Method Name

REVEI: Consultative Interpretation

HGBCE: Capillary Electrophoresis

HPLC: Cation Exchange/High Performance Liquid Chromatography (HPLC)

MASS: Mass Spectrometry (MS)

P50P: Hemox-Analyzer Measures and Plots O(2) Saturation

IEF: Electrophoresis

HPFH: Flow Cytometry

UNHB Isopropanol and Heat Stability

VHLE: Polymerase Chain Reaction (PCR) followed by DNA Sequence Analysis

REVE0: Consultative Interpretation

Reporting Name

Erythrocytosis Evaluation

Specimen Type

Control
WB Sodium Heparin
Whole Blood EDTA

Specimen Minimum Volume

EDTA Blood: 2.5 mL
Heparin Blood: 1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Control Refrigerated 72 hours GREEN TOP/HEP
WB Sodium Heparin Refrigerated 72 hours GREEN TOP/HEP
Whole Blood EDTA Refrigerated 72 hours

Clinical Information

Erythrocytosis (polycythemia) is identified by a sustained increase in hemoglobin or hematocrit. An isolated increase in red blood cells (RBC) count (in the absence of chronic phlebotomy or coincident iron deficiency) may occur in thalassemia or other causes and does not indicate erythrocytosis. Erythrocytosis may occur as a primary disorder, due to an intrinsic defect of bone marrow stem cells, or secondary, in response to increased serum erythropoietin (EPO) levels. Secondary erythrocytosis is associated with a number of disorders including chronic lung disease, chronic increase in carbon monoxide, cyanotic heart disease, high-altitude living, renal cysts and tumors, hepatoma, and other EPO-secreting tumors. When these common causes of secondary erythrocytosis are excluded, a heritable cause involving hemoglobin or erythrocyte regulatory mechanisms may be present. It is important to differentiate polycythemia vera (PV) from heritable causes of erythrocytosis, the latter of which can be passed to progeny but do not carry the risks of clonal evolution or marrow fibrosis associated with PV.

 

The most common cause of hereditary erythrocytosis is the presence of high-oxygen-affinity (HOA) hemoglobin. A subset of hemoglobins with increased oxygen (O2) affinity result in clinically evident erythrocytosis caused by decreased O2 unloading at the tissue level. Many are asymptomatic; however some patients have recurrent headaches, dizziness, fatigue and restless legs. A minor subset of patients has thrombotic episodes. Affected individuals can be plethoric and many are misclassified as polycythemia vera. The oxygen dissociation curve is left-shifted (p50 values are decreased). Changes to the amino acid sequence of the hemoglobin molecule may distort the protein structure, affecting O2 transport or unloading and the binding of 2,3-bisphosphoglyceric acid (2,3-BPG). 2,3-BPG stabilizes the deoxygenated state of hemoglobin. Therefore a decrease in the 2,3-BPG concentration results in greater O2 affinity of the normal hemoglobin molecule. A few cases of erythrocytosis have been associated with a reduction in 2,3-BPG formation. This is most commonly due to variants in the converting enzyme, bisphosphoglycerate mutase (BPGM). Truncating variants in the erythropoietin receptor gene, EPOR, have been shown to be a cause of the autosomal dominant primary familial and congenital polycythemia (PFCP)(OMIM 133100). In addition, oxygen sensing pathway variants, EPAS1(HIF2A)(OMIM 611783); EGLN1(PHD2)(OMIM 609820), and VHL (OMIM 263400) cause hereditary erythrocytosis and a subset are associated with pheochromocytoma and paragangliomas. All have shown an autosomal dominant pattern of inheritance, except VHL-associated erythrocytosis, which is an autosomal recessive disorder. Homozygous VHL R200W alterations have been shown to be causative of Chuvash polycythemia, an endemic heritable erythrocytic disorder first described in Russia but subsequently found in other ethnic groups. The prevalence of causative variants in EPOR and the oxygen sensing pathway genes is unknown, but in our experience they are less prevalent than genetic variants that cause HOA hemoglobin variants, and much less prevalent than polycythemia vera. Because there are many causes of erythrocytosis, an algorithmic and reflexive testing strategy is useful for evaluating these disorders. Initial JAK2 V617F alteration testing and serum EPO levels are important with p50 results further stratifying JAK2-negative cases. Importantly, a significant subset of HOA hemoglobin variants can be electrophoretically silent on multiple routine screening platforms; however, most if not all of HOAs can be identified with addition of the mass spectrometry method. Our extensive experience with these disorders allows an economical, comprehensive evaluation with high sensitivity.

Reference Values

Definitive results and an interpretive report will be provided.

Interpretation

The evaluation includes testing for a hemoglobinopathy and oxygen (O2) affinity of the hemoglobin molecule. An increase in O2 affinity is demonstrated by a shift to the left in the O2 dissociation curve (decreased p50 result). Reflex testing for EPOR, EGLN1 (PHD2), EPAS1 (HIF2a), VHL, and BPGM will be performed as needed.

 

A hematopathologist expert in these disorders will evaluate the case, appropriate tests are performed, and an interpretive report is issued.

Clinical Reference

1. Patnaik MM, Tefferi A: The complete evaluation of erythrocytosis: congenital and acquired. Leukemia. 2009 May;23(5):834-844

2. McMullin MF: The classification and diagnosis of erythrocytosis. Int J Lab Hematol. 2008;30:447-459

3. Percy MJ, Lee FS: Familial erythrocytosis: molecular links to red blood cell control. Haematologica. 2008 Jul;93(7):963-967

4. Huang LJ, Shen YM, Bulut GB: Advances in understanding the pathogenesis of primary familial and congenital polycythaemia. Br J Haematol. 2010 Mar;148(6):844-852

5. Maran J, Prchal J: Polycythemia and oxygen sensing. Pathol Biol. 2004;52:280-284

6. Lee F: Genetic causes of erythrocytosis and the oxygen-sensing pathway. Blood Rev. 2008;22:321-332

7. Merchant SH, Oliveira JL, Hoyer JD, Viswanatha DS: Erythrocytosis. In: His ED, ed. Hematopathology. 2nd ed. Elsevier Saunders; 2012: 722-723

8. Zhuang Z, Yang C, Lorenzo F, et al: Somatic HIF2A gain-of-function mutations in paraganglioma with polycythemia. N Engl J Med. 2012 Sep 6;367(10):922-930

9. Oliveira JL, Coon LM, Frederick LA, et al: Genotype-phenotype correlation of hereditary erythrocytosis mutations, a single center experience. Am J Hematol. 2018; May 23

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

83020-26-Erythrocytosis Interpretation

83020-Hemoglobin Electrophoresis

83021-HPLC Hb Variant

82820-Hemoglobin O2 affinity (p50)

83789-Hemoglobin Variant by Mass Spectroscopy (MS), Blood

83068 (if appropriate)

82664 (if appropriate)

88184 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
REVE1 Erythrocytosis Evaluation In Process

 

Result ID Test Result Name Result LOINC Value
60286 Hb Variant by Mass Spec, B No LOINC Needed
37951 P50 Shipping Control Vial No LOINC Needed
37950 Oxygen Dissociation P50, RBC 65343-6
41927 Hb A 20572-4
65615 HPLC Hb Variant, B No LOINC Needed
608426 Erythrocytosis Interpretation 59466-3
608440 Reviewed By 18771-6
41928 Hb F 4576-5
41929 Hb A2 4551-8
41930 Variant 1 24469-9
41931 Variant 2 24469-9
41932 Variant 3 24469-9
41933 HGBCE Interpretation 78748-1
Mayo Clinic Laboratories | Hematology Catalog Additional Information:

mml-benign-hematology-disorders