Test Code LPLFX Lymphoplasmacytic Lymphoma/Waldenstrom Macroglobulinemia, MYD88 L265P with Reflex to CXCR4, Varies
Shipping Instructions
Whole blood or bone marrow specimens must arrive within 10 days of collection.
Necessary Information
The following information is required:
1. Pertinent clinical history
2. Clinical or morphologic suspicion
3. Date and time of collection
4. Specimen source
Specimen Required
Submit only 1 of the following specimens:
Preferred:
Specimen Type: Bone marrow
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD)
Specimen Volume: 2 mL
Collection Instructions:
1. Invert several times to mix bone marrow
2. Send bone marrow specimen in original tube. Do not aliquot.
3. Label specimen as bone marrow
Specimen Stability Information: Ambient (preferred)/Refrigerated
Specimen Type: Paraffin-embedded tissue
Container/Tube: Paraffin block
Specimen Stability: Ambient
Specimen Type: Paraffin-embedded bone marrow aspirate clot
Container/Tube: Paraffin block
Specimen Stability: Ambient
Specimen Type: Tissue
Slides: Unstained slides
Specimen Volume: 10 to20 slides
Additional Information: Tissue must demonstrate involvement by a hematologic neoplasm (eg, acute myelocytic leukemia), not solid tumors.
Specimen Stability Information: Ambient
Acceptable:
Specimen Type: Whole blood
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD)
Specimen Volume: 3 mL
Collection Instructions:
1. Invert several times to mix blood
2. Send whole blood specimen in original tube. Do not aliquot.
3. Label specimen as blood
Specimen Stability Information: Ambient (preferred)/Refrigerated
Specimen Type: Extracted DNA
Container/Tube: 1.5- to 2-mL tube with indication of volume and concentration of the DNA
Specimen Volume: Entire specimen
Collection Instructions: Label specimen as extracted DNA and list the specimen source. Include indication of volume and concentration of the DNA.
Specimen Stability Information: Frozen (preferred)/Refrigerated/Ambient
Forms
1. Hematopathology Patient Information (T676)
2. If not ordering electronically, complete, print, and send a Hematopathology/Cytogenetics Test Request (T726) with the specimen.
Useful For
Establishing a diagnosis of lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia (LPL/WM)
Helping distinguish LPL/WM low-grade B-cell lymphoma from other subtypes
Aiding in the prognosis and clinical management of lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
CXCFX | CXCR4, Gene Mutation, Reflex | Yes, (order CXLPL), Bill Only | No |
Testing Algorithm
The algorithm starts with the sensitive MYD88 L265P testing by allele-specific polymerase chain reaction. If a MYD88 L265P variant is detected, additional CXCR4 testing will be performed. If a MYD88 L265P variant is not detected, the algorithm ends, and no further testing is necessary.
Special Instructions
Method Name
Allele-Specific Polymerase Chain Reaction (AS-PCR)/Bridged Nucleic Acids (BNA) Clamp Sanger Sequencing/Routine Sanger Sequencing
(BNAClamp is utilized pursuant to a license agreement with BNA Inc.)
Reporting Name
Reflex Testing of MYD88 and CXCR4Specimen Type
VariesSpecimen Minimum Volume
Whole blood, Bone marrow: 1 mL
Extracted DNA: 50 mcL with a concentration of at least 20 nanograms per mcL
Other specimen types: See Specimen Required
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Varies | Varies | 10 days |
Reject Due To
Gross hemolysis | Reject |
B5-fixed tissues Decalcified bone marrow biopsies Methanol-acetic acid (MAA)-fixed pellets Paraffin shavings Frozen tissue Moderately to severely clotted |
Reject |
Clinical Information
The MYD88 L265P abnormality is highly associated (>90%) with the pathologic diagnosis of lymphoplasmacytic lymphoma and the clinical syndrome of Waldenstrom macroglobulinemia (LPL/WM), particularly in the setting of an elevated IgM serum monoclonal paraprotein.
CXCR4 mutations are identified in approximately 30% to 40% of LPL/WM patients and are almost always in association with MYD88 L265P, which is highly prevalent in this neoplasm. The status of CXCR4 mutations in the context of MYD88 L265P is clinically relevant as important determinants of clinical presentation, overall survival and therapeutic response to ibrutinib. A MYD88-L265P/CXCR4-WHIM (C-terminus nonsense/frameshift variants) molecular signature is associated with intermediate to high bone marrow disease burden and serum IgM levels, less adenopathy, and intermediate response to ibrutinib in previously treated patients. A MYD88-L265P/CXCR4-WT (wildtype) molecular signature is associated with intermediated bone marrow disease burden and serum IgM levels, more adenopathy, and highest response to ibrutinib in previously treated patients. A MYD88-WT/CXCR4-WT molecular signature is associated with inferior overall survival, lower response to ibrutinib therapy in previously treated patients, and lower bone marrow disease burden in comparison to those harboring a MYD88-L265 variant.
Reference Values
MYD88 L265P: Mutation present or absent based on expected variant polymerase chain reaction product size for the MYD88 gene (NCBI accession NM_002468.4).
CXCR4: Mutation present or absent in the test region c. 898-1059 (amino acids 300-353) of the CXCR4 gene (NCBI NM_003467.2, GRCh37).
Interpretation
Mutation present or not detected; an interpretive report will be issued.
Day(s) Performed
Monday through Friday
Report Available
7 to 10 daysSpecimen Retention Time
Blood/Bone marrow: 2 weeks; Extracted DNA: 3 monthsPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest Classification
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
81305
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
LPLFX | Reflex Testing of MYD88 and CXCR4 | 82140-5 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
MP042 | Specimen Type | 31208-2 |
601511 | LPLFX Reflex Result | 82140-5 |
601510 | Final Diagnosis | 50398-7 |