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HelpOrder Code RBCS Relative B-Cell Subset Analysis Percentage, Blood
Useful For
Screening for humoral or combined immunodeficiencies, including common variable immunodeficiency, hyper IgM syndrome, among others, where B-cell subset distribution information is desired
Assessing B-cell subset reconstitution after hematopoietic cell or bone marrow transplant
Assessing B-cell subset reconstitution following recovery of B cells after B-cell-depleting immunotherapy
This test is not indicated for the evaluation of lymphoproliferative disorders (eg, leukemia, lymphoma, multiple myeloma).
This test should not be used to monitor B-cell counts to assess B-cell depletion in patients on B-cell-depleting therapies.
Method Name
Flow Cytometry
Reporting Name
Relative B Cell Subset Analysis %Specimen Type
Whole Blood EDTAOrdering Guidance
This test should be ordered only when percentages are needed for the reportable B-cell subsets. If both percentages and absolute counts are needed for the reportable B-cell subsets, order IABCS / B-Cell Phenotyping Profile for Immunodeficiency and Immune Competence Assessment, Blood.
Shipping Instructions
Testing performed Monday through-Friday. Specimens not received by 4 p.m. Central time on Fridays may be canceled.
Specimens arriving on the weekend and observed holidays may be canceled.
Collect and package specimens as close to shipping time as possible. Ship specimens overnight.
It is recommended that specimens arrive within 24 hours of collection.
Necessary Information
The ordering healthcare professional's name and phone number are required.
Specimen Required
Container/Tube: Lavender top (EDTA)
Specimen Volume:
≤14 years: 4 mL
>14 years: 10 mL
Collection Instructions:
1. Send whole blood specimen in original tube. Do not aliquot.
2. Label specimen as blood for RBCS.
Additional Information: For serial monitoring, it is recommended that specimens are collected at the same time of day.
Specimen Minimum Volume
≤14 years: 3 mL; >14 years: 5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole Blood EDTA | Refrigerated | 48 hours | PURPLE OR PINK TOP/EDTA |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
Reference Values
The appropriate age-related reference values will be provided on the report.
Method Description
Peripheral blood mononuclear cells are isolated from whole blood using a Ficoll gradient and used in the staining protocol. The assay involves a multicolor 5-tube panel for the following antibodies: CD45, CD19, CD20, CD27, IgD, IgM, CD38, and CD21. After the staining with specific antibody, the cells are washed and fixed with paraformaldehyde and then analyzed by flow cytometry on a BD FACSCanto II instrument. The cell-surface expression is denoted as the percent of CD19+ B cells expressing each of the specific markers. CD19+ and CD20+ B cells are expressed as a percent of the total lymphocytes (CD45+).(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
86356 x7