Test Catalog

Test Id : MPNR

Myeloproliferative Neoplasm, JAK2 V617F with Reflex to CALR and MPL, Varies

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

Aiding in the distinction between a reactive cytosis and a chronic myeloproliferative disorder

 

Evaluating for variants in JAK2, CALR, and MPL genes in an algorithmic process

Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.

Test Id Reporting Name Available Separately Always Performed
CALX CALR, Gene Mutation, Exon 9, Reflex No, (bill only) No
MPLR MPL Exon 10 Mutation Detection, R No, (bill only) No

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

This reflex test sequentially evaluates for the common major gene variants associated with non-BCR-ABL1-positive myeloproliferative neoplasms until a variant is identified. The testing sequence is based on the reported frequency of gene variants in this disease group. Initial testing evaluates for the presence of the JAK2 V617F variant. If this result is negative or very low positive (0.06%-0.6%), testing proceeds with assessment for CALR gene variants. If the CALR result is also negative, then testing proceeds to evaluate for variants in exon 10 of the MPL gene. If either JAK2 V617F (>0.6%) or CALR variants are detected in the process, the testing algorithm ends; therefore, the complete reflex is followed only in the event of sequential negative variant. An integrated report is issued with the summary of test results.

 

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

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

Quantitative Polymerase Chain Reaction (qPCR)

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

MPN (JAK2 V617F, CALR, MPL) Reflex

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

83872-JAK2B

Janus kinase 2 gene

Tyrosine Kinase Mutation

CALR

Calreticulin

Essential Thrombocythemia

JAK2-negative Myeloproliferative Neoplasm

Myelofibrosis

Myeloproliferative Disorder

Myeloproliferative Neoplasm (MPN)

Primary Myelofibrosis

MPL S505

MPLW515

Myeloproliferative leukemia virus oncogene

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

This reflex test sequentially evaluates for the common major gene variants associated with non-BCR-ABL1-positive myeloproliferative neoplasms until a variant is identified. The testing sequence is based on the reported frequency of gene variants in this disease group. Initial testing evaluates for the presence of the JAK2 V617F variant. If this result is negative or very low positive (0.06%-0.6%), testing proceeds with assessment for CALR gene variants. If the CALR result is also negative, then testing proceeds to evaluate for variants in exon 10 of the MPL gene. If either JAK2 V617F (>0.6%) or CALR variants are detected in the process, the testing algorithm ends; therefore, the complete reflex is followed only in the event of sequential negative variant. An integrated report is issued with the summary of test results.

 

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

Specimen Type
Describes the specimen type validated for testing

Varies

Shipping Instructions

Specimen must arrive within 7 days of collection.

Necessary Information

The following information is required:

1. Pertinent clinical history

2. Clinical or morphologic suspicion

3. Date of collection

4. Specimen source

ORDER QUESTIONS AND ANSWERS

Question ID Description Answers
MP023 Specimen Type

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

Submit only 1 of the following specimens:

 

Specimen Type: Blood

Container/Tube: Lavender top (EDTA) or yellow top (ACD solution B)

Specimen Volume: 3 mL

Collection Instructions:

1. Invert several times to mix blood.

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

3. Label specimen as blood.

Specimen Stability Information: Ambient (preferred)/Refrigerate

 

Specimen Type: Bone marrow

Container/Tube: Lavender top (EDTA) or yellow top (ACD solution B)

Specimen Volume: 2 mL

Collection Instructions:

1. Invert several times to mix bone marrow.

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

3. Label specimen as bone marrow.

Specimen Stability Information: Ambient (preferred)/Refrigerate

 

Specimen Type: Extracted DNA from blood or bone marrow

Container/Tube: 1.5- to 2-mL tube

Specimen Volume: Entire specimen

Collection Instructions: Label specimen as extracted DNA from blood or bone marrow and provide indication of volume and concentration of the DNA.

Specimen Stability Information: Frozen (preferred)/Refrigerate/Ambient

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

Forms

If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.

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

Blood and Bone marrow: 0.5 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Paraffin-embedded bone marrow aspirate clot or biopsy blocks
Slides
Paraffin shavings
Moderately to severely clotted
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
Varies Varies (preferred) 7 days

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

Aiding in the distinction between a reactive cytosis and a chronic myeloproliferative disorder

 

Evaluating for variants in JAK2, CALR, and MPL genes in an algorithmic process

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

This reflex test sequentially evaluates for the common major gene variants associated with non-BCR-ABL1-positive myeloproliferative neoplasms until a variant is identified. The testing sequence is based on the reported frequency of gene variants in this disease group. Initial testing evaluates for the presence of the JAK2 V617F variant. If this result is negative or very low positive (0.06%-0.6%), testing proceeds with assessment for CALR gene variants. If the CALR result is also negative, then testing proceeds to evaluate for variants in exon 10 of the MPL gene. If either JAK2 V617F (>0.6%) or CALR variants are detected in the process, the testing algorithm ends; therefore, the complete reflex is followed only in the event of sequential negative variant. An integrated report is issued with the summary of test results.

 

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

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

The Janus kinase 2 gene (JAK2) codes for a tyrosine kinase (JAK2) that is associated with the cytoplasmic portion of a variety of transmembrane cytokine and growth factor receptors important for signal transduction in hematopoietic cells. Signaling via JAK2 activation causes phosphorylation of downstream signal transducers and activators of transcription (STAT) proteins (eg, STAT5) ultimately leading to cell growth and differentiation. BCR-ABL1-negative myeloproliferative neoplasms (MPN) frequently harbor an acquired single nucleotide variant in JAK2 characterized as c.G1849T; p. Val617Phe (V617F). JAK2 V617F is present in 95% to 98% of polycythemia vera (PV), and 50% to 60% of primary myelofibrosis (PMF) and essential thrombocythemia (ET). It has also been described infrequently in other myeloid neoplasms, including chronic myelomonocytic leukemia and myelodysplastic syndrome. Detection of JAK2 V617F is useful to help establish the diagnosis of MPN. However, a negative JAK2 V617F result does not indicate the absence of MPN. Other important molecular markers in BCR-ABL1-negative MPN include CALR exon 9 variant (20%-30% of PMF and ET) and MPL exon 10 variant (5%-10% of PMF and 3%-5% of ET). Variants in JAK2, CALR, and MPL are essentially mutually exclusive. A CALR variant is associated with decreased risk of thrombosis in both ET and PMF and confers a favorable clinical outcome in PMF patients. A triple negative (JAK2 V617F, CALR, and MPL-negative) genotype is considered a high-risk molecular signature in PMF.

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.

An interpretive report will be provided.

Interpretation
Provides information to assist in interpretation of the test results

The results will be reported as 1 of the 4 following states:

-Positive for JAK2 V617F variant

-Positive for CALR variant

-Positive for MPL variant

-Negative for JAK2 V617F, CALR, and MPL variants

 

Positive variant status is highly suggestive of a myeloid neoplasm but must be correlated with clinical and other laboratory features for definitive diagnosis.

 

Negative variant status does not exclude the presence of a myeloproliferative neoplasm or other neoplasms.

 

Results below the laboratory cutoff for positivity are of unclear clinical significance at this time.

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

A positive result is not specific for a particular subtype of myeloproliferative neoplasm and clinicopathologic correlation is necessary in all cases.

 

A negative result does not exclude the presence of a myeloproliferative neoplasm or other neoplastic process.

 

In rare cases, a variant other than JAK2 V617F may be present in an area that interferes with primer or probe binding, which may cause a false-negative result.

 

If this test is ordered in the setting of erythrocytosis and suspicion of polycythemia vera, interpretation requires correlation with a concurrent or recent prior bone marrow evaluation.

Supportive Data

Analytical sensitivity is determined at 0.06% (by dilution of a JAK2 V617F-positive cell line into a negative cell line DNA).

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

1. Baxter EJ, Scott LM, Campbell PJ, et al: Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders. Lancet 2005 March 16;365(9464):1054-1061

2. James C, Ugo V, Le Couedic JP, et al: A unique clonal JAK2 mutation leading to constitutive signaling causes polycythaemia vera. Nature 2005 April 28;434(7037):1144-1148

3. Kralovics R, Passamonti F, Buser AS, et al: A gain-of-function mutation of JAK2 in myeloproliferative disorders. N Engl J Med 2005;352:1779-1790

4. Steensma DP, Dewald GW, Lasho TL, et al: The JAK2 V617F activating tyrosine kinase mutation is an infrequent event in both "atypical" myeloproliferative disorders and the myelodysplastic syndrome. Blood 2005;106:1207-1209

5. Klampfl T, Gisslinger H, Harutyunyan AS, et al: Somatic mutation of calreticulin in myeloproliferative neoplasms. N Engl J Med 2013;369:2379-2390

6. Nangalia J, Massie CE, Baxter EJ, et al: Somatic CALR mutation in myeloproliferative neoplasms with nonmutated JAK2. N Engl J Med 2013;369:2391-2405

7. Pikman Y, Lee BH, Mercher T, et al: MPLW515L is a novel somatic activating mutation in myelofibrosis with myeloid metaplasia. PLoS Med 2006;3:e270

8. Pardanani A, Levine R, Lasho T, et al: MPL515 mutations in myeloproliferative and other myeloid disorders: a study of 1182 patients. Blood 2006;108:3472-3476

9. Kilpivaara O, Levine RL: JAK2 and MPL mutations in myeloproliferative neoplasms: discovery and science. Leukemia 2008;22:1813-1817

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

Genomic DNA is extracted, and 2 polymerase chain reaction (PCR) reactions are used for each sample. In each reaction, a short fragment of genomic DNA, including the variant site, is amplified using quantitative PCR in a real-time PCR instrument. In one reaction, the reverse primer matches the altered sequence and the PCR conditions are such that it will only bind altered DNA. In the second reaction, the reverse primer matches the wild-type sequence and the PCR conditions are such that it will only bind the wild-type sequence. In both reactions, the PCR is monitored using TaqMan probe chemistry. The amount of altered DNA and the amount of wild-type DNA is measured for each sample. In each run, the amount of altered and wild-type DNA in a calibrator DNA sample is also measured.

  

The final result is reported as % JAK2 V617F of total JAK2(Unpublished Mayo method)

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.

7 to 10 days

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

DNA: 3 months

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.

  • 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 Regional Manager. 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. 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.

81270-JAK2 (Janus kinase 2) (eg, myeloproliferative disorder) gene analysis, p.Val617Phe (V617F) variant
81219-CALR (calreticulin) (eg, myeloproliferative disorders), gene analysis, common variants in exon 9 (if appropriate)
81339-MPL (MPL proto-oncogene, thrombopoietin receptor) (eg, myeloproliferative disorder) gene analysis; sequence analysis, exon 10 (if appropriate)

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
MPNR MPN (JAK2 V617F, CALR, MPL) Reflex In Process
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.
36687 Final Diagnosis 22637-3
39725 MPNR Result No LOINC Needed

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