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Test Code LABMRDMM Multiple Myeloma Minimal Residual Disease, Flow Cytometry, Bone Marrow

Additional Codes

Test Name in EPIC EPIC Test Code Mnemonic Mayo Test ID

Multiple Myeloma MRD by Flow, BM

 LABMRDMM MRDMM MRDMM

 


Ordering Guidance


This test should be ordered on patients treated for multiple myeloma to confirm remission has been achieved, annual follow-up of those in remission, or in uncertain remission.

 

This test should not be ordered on known relapsing patients or at diagnosis. For these situations or if fluorescence in situ hybridization is requested, order either PCPRO / Plasma Cell DNA Content and Proliferation, Bone Marrow or MSMRT / Mayo Algorithmic Approach for Stratification of Myeloma and Risk-Adapted Therapy Report, Bone Marrow



Shipping Instructions


It is recommended that specimens arrive within 2 days of collection. Collect and package specimen as close to shipping time as possible.



Necessary Information


1. Include patient's disease state (untreated, treated, monoclonal gammopathy of undetermined significance, stable).

2. Indicate if patient is on anti-CD38 therapy.

3. Provide Immunofix information if available.



Specimen Required


Specimen Type: Redirected bone marrow

Container/Tube:

Preferred: Yellow top (ACD solution A or B)

Acceptable: Lavender top (EDTA)

Specimen Volume: 4 mL


Useful For

Detecting low level (minimal residual disease) myeloma cells after therapy.

Disease States

  • Amyloidosis

Method Name

Immunophenotyping for Minimal Residual Disease (MRD)

Reporting Name

Multiple Myeloma MRD by Flow, BM

Specimen Type

Bone Marrow

Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Bone Marrow Ambient (preferred) 72 hours
  Refrigerated  72 hours

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability

Clinical Information

Multiple myeloma is an incurable malignant neoplasm of plasma cells. One of the best prognostic factors in multiple myeloma is the level of minimal residual disease post chemotherapy or autologous stem cell transplantation. The greater depth of the response (less malignant cells present), the longer time to progression and overall survival.(1)

Reference Values

An interpretive report will be provided.

 

Interpretation

The interpretation of the test is done by evaluating automated and manually gated populations to isolate abnormal plasma cells. If there is an abnormal plasma cell population (cluster of 20 cells or more), then the result is minimal residual disease (MRD)-positive, with the percentage of abnormal plasma cells out of total analyzed events. If no abnormal population is found, then the result will be interpreted as MRD-negative.

 

This test will be processed as a laboratory consultation. An interpretation of the immunophenotypic findings and correlation with the previous patient history will be provided by a hematopathologist for every case.

Cautions

There are situations in which current gating strategies are insufficient to identify abnormal plasma cells. This can occur if the abnormal plasma cells do not phenotypically differ from normal plasma cells. In addition, in patients who have undergone therapeutic antibody treatment (anti-CD38, for example), decreased antigen expression on plasma cells may interfere with the gating strategy.

Method Description

Flow cytometric immunophenotyping for minimal residual disease (MRD) of bone marrow is performed using the following antibodies:

Tube 1: CD138, CD27, CD38, CD56, CD45, CD19, CD117, and CD81.

Tube 2: CD138, CD27, CD38, CD56, CD45, CD19, cyKappa, and cyLambda.

Abnormal plasma cell populations are detected through demonstrating CD38 (multiepitope) and CD138 positivity along with immunoglobulin light chain restriction (ie, the presence of either predominately kappa or lambda immunoglobulin light chains) and abnormality of CD56, CD117, CD27, CD81, CD19 and/or CD45 expression.

 

The sensitivity of this assay is conservatively estimated to be 0.001% (1 x 10[-5]) with a minimum number of 2 x 10(-6) total events collected, and an abnormal plasma cell immunophenotype detected in a cluster of at least 20 cells and can be as high as 0.0002% (2 x 10[-6]). The sensitivity of the assay will be lower in samples with less than 2 x 10(-6) total events acquired. The validated limit of detection (sensitivity) meets current National Comprehensive Cancer Network, International Myeloma Working Group, and EuroFlow guidelines for MRD assessment by flow cytometry in multiple myeloma. The percentage of clonal plasma cells estimated by flow cytometry is affected by specimen processing and antigen loss with specimen aging. MRD reporting is affected by sample volume and cellularity.(Unpublished Mayo method)

Day(s) Performed

Preanalytical processing: Monday through Saturday

Results reported: Monday through Friday

Report Available

2 to 4 days

Specimen Retention Time

14 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test 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

88184-Flow Cytometry; first cell surface, cytoplasmic or nuclear marker

88185 x 9-Flow Cytometry; additional cell surface, cytoplasmic or nuclear marker

88188-Flow Cytometry Interpretation, 9 to 15 Markers

LOINC Code Information

Test ID Test Order Name Order LOINC Value
MRDMM Multiple Myeloma MRD by Flow, BM 93022-2

 

Result ID Test Result Name Result LOINC Value
CK146 % Minimal Residual Disease (MRD) 93021-4
CK147 % Normal Plasma Cells (of total PC) 93020-6
CK148 Non-Aggregate Events 38257-2
CK149 Total Plasma Cell Events 93019-8
CK150 Poly PC Events 93018-0
CK151 Abnormal PC Events 93017-2
615796 % B-cell Precursors 101131-1
615797 % Mast Cells 101130-3
616082 Validated Assay Sensitivity 101129-5
616083 Lower Limit of Quantitation (LLOQ) 87706-8
615798 Patient / Sample Theoretical LOQ 101128-7
CK152 Final Diagnosis 74226-2

Forms

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