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HelpTest Code MRDMM Multiple Myeloma Minimal Residual Disease, Flow Cytometry, Bone Marrow
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, BMSpecimen Type
Bone MarrowSpecimen 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 suitabilityClinical 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 daysPerforming 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 |