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|---|---|
| Email: | mcl@mayo.edu |
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| Values are valid only on day of printing | |
Test Id : RBCS
Relative B-Cell Subset Analysis Percentage, Blood
Useful For
Suggests clinical disorders or settings where the test may be helpful
Suggests clinical disorders or settings where the test may be helpful
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.
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.
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 |
|---|---|---|---|
| CVID | CVID Confirmation Flow Panel | Yes | No |
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
This test should be ordered only when percentages (relative distribution of B cell subsets within the total B-cell population) 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.
Method Name
A short description of the method used to perform the test
A short description of the method used to perform the test
Fluorescent Flow Cytometry
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
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
Lists a shorter or abbreviated version of the Published Name for a test
Relative B Cell Subset Analysis %
Aliases
Lists additional common names for a test, as an aid in searching
Lists additional common names for a test, as an aid in searching
B Cell
B Cell Assessment
B Cell CVID
B Cell Immunodeficiency
B Cell Phenotype
B Cell Phenotyping
B Cell Subset
B-cell Assessment
B-cell CVID
CD19
CD27
Class-switching
Common Variable Immunodeficiency
CVID
Humoral Immunodeficiency
IgD
IgM
IgM Memory B-cell
Immune Reconstitution
Immunodeficiency
Kidney Transplant
Mature B-cell
Memory B-cell
Plasmablast
Transitional B-cell
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
This test should be ordered only when percentages (relative distribution of B cell subsets within the total B-cell population) 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.
Specimen Type
Describes the specimen type validated for testing
Describes the specimen type validated for testing
Whole Blood EDTA
Ordering 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
Specimens are required to be received in the laboratory on weekdays and by 4 p.m. on Friday. No weekend processing. 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
Ordering physician's name and phone number are required.
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Specimen Type: Whole blood
Container/Tube: Lavender top (EDTA)
Specimen Volume:
< or =14 years of age: 4 mL
>14 years of age: 10 mL
Collection Instructions:
1. Send whole blood specimen in original tube. Do not aliquot.
2. Label specimen as blood for RBCS / Relative B Cell Subset Analysis Percentage, Blood.
Additional Information: For serial monitoring, it is recommended that specimens are collected at the same time of day.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory
< or =14 years of age: 3 mL; >14 years of age: 5 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Gross lipemia | 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
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 |
|---|---|---|---|
| Whole Blood EDTA | Refrigerated (preferred) | 48 hours | PURPLE OR PINK TOP/EDTA |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Suggests clinical disorders or settings where the test may be helpful
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.
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
This test should be ordered only when percentages (relative distribution of B cell subsets within the total B-cell population) 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.
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
The adaptive immune response includes both cell-mediated (mediated by T cells and natural killer cells) and humoral immunity (mediated by B cells). After antigen recognition and maturation in secondary lymphoid organs, some antigen-specific B cells terminally differentiate into antibody-secreting plasma cells or become memory B cells. Memory B cells are of 3 subsets: marginal zone B cells (MZ or non-switched memory), class-switched memory B cells, and IgM-only memory B cells. Decreased B-cell numbers, B-cell function, or both, result in immune deficiency states and increased susceptibility to infections. These decreases may be either primary (genetic) or secondary. Secondary causes include medications, malignancies, infections, and autoimmune disorders.
Common variable immunodeficiency (CVID), a disorder of B-cell function, is the most prevalent primary immunodeficiency with a prevalence of 1:25,000 to 1:50,000.(1) CVID has a bimodal presentation with a subset of patients presenting in early childhood and a second set presenting between 15 and 40 years of age, or occasionally even later. Many different genetic defects have been associated with CVID; TACI variants account for 8% to 15% of CVID cases.
CVID is characterized by hypogammaglobulinemia usually involving most or all of the Ig classes (IgG, IgA, IgM, and IgE), impaired functional antibody responses, and recurrent sinopulmonary infections.(1,2) B-cell numbers may be normal or decreased. A minority of CVID patients (5%-10%) have very low B-cell counts (<1% of peripheral blood leukocytes), while another subset (5%-10%) exhibit noncaseating, sarcoid-like granulomas in different organs and also tend to develop a progressive T-cell deficiency.(1) Of all patients with CVID, 25% to 30% have increased numbers of CD8 T cells and a reduced CD4:CD8 ratio (<1). Studies have shown the clinical relevance of classifying CVID patients by assessing B-cell subsets, since changes in different B-cell subsets are associated with particular clinical phenotypes or presentations.(3,4)
The B-cell phenotyping assay can be used in the diagnosis of hyper-IgM syndromes, which are characterized by increased or normal levels of IgM with low IgG and/or IgA.(5) Patients with hyper-IgM syndromes can have 1 of 5 known genetic defects in the CD40L, CD40, AID (activation-induced cytidine deaminase), UNG (uracil DNA glycosylase), and NEMO (NF-kappa B essential modulator) genes.(5) Variants in CD40L and NEMO are inherited in an X-linked fashion, while variants in the other 3 genes are inherited in an autosomal recessive fashion. Patients with hyper-IgM syndromes have a defect in isotype class-switching, which leads to a decrease in class-switched memory B cells, with or without an increase in non-switched memory B cells and IgM-only memory B cells.
In addition to its utility in the diagnosis of the above-described primary immunodeficiencies, B-cell phenotyping may be used to assess reconstitution of B-cell subsets after hematopoietic stem cell or bone marrow transplant. This test is also used to monitor B-cell-depleting therapies, such as Rituxan (rituximab) and Zevalin (ibritumomab tiuxetan).
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.
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.
The appropriate age-related reference values will be provided on the report.
Interpretation
Provides information to assist in interpretation of the test results
Provides information to assist in interpretation of the test results
The assay provides semiquantitative information on the various B-cell subsets. Each specimen is evaluated for B-cell subsets with respect to the total number of CD19+ B cells present in the peripheral blood mononuclear cell population, compared to the reference range. In order to verify that there are no CD19-related defects, CD20 is used as an additional pan-B-cell marker (expressed as percentage of CD45+ lymphocytes).
The B-cell panel assesses the following B-cell subsets:
-CD19+=B cells expressing CD19 as a percent of total lymphocytes
-CD19+ CD27+=total memory B cells
-CD19+ CD27+ IgD+ IgM+=marginal zone or non-switched memory B cells
-CD19+ CD27+ IgD- IgM+=IgM-only memory B cells
-CD19+ CD27+ IgD- IgM-=class-switched memory B cells
-CD19+ IgM+=IgM B cells
-CD19+ CD38+ IgM+=transitional B cells
-CD19+ CD38+ IgM-=plasmablasts
-CD19+ CD21-=CD21-negative B cells
-CD19+ CD21+=CD21-positive B cells
-CD19+ CD20+=B cells coexpressing both CD19 and CD20 as a percent of total lymphocytes
For isotype class-switching and memory B-cell analyses, the data will be reported as being consistent or not consistent with a quantitative defect in memory subsets and/or class switching. If a defect is present in any of these B-cell subpopulations, further correlation with clinical presentation and additional functional, immunological, and genetic laboratory studies will be suggested, if appropriate.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This assay and the reference range reported are based on analysis of B cells derived from the mononuclear cell fraction of peripheral whole blood and, therefore, total CD19+ B cell quantitation may not be identical to those performed on whole blood (eg, TBBS / Quantitative Lymphocyte Subsets: T, B, and Natural Killer (NK) Cells, Blood).
This test should not be used to monitor B-cell counts to assess B-cell depletion in patients on B-cell-depleting therapies; order CD20B / CD20 on B Cells, Blood for that purpose; this test is meant to be used specifically for assessing the relative distribution of B-cell subsets within the total B-cell pool.
Timing and consistency in timing of blood collection is critical when serially monitoring patients for lymphocyte subsets.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
Recommendations for in-depth reading of a clinical nature
1. Warnatz K, Denz A, Drager R, et al: Severe deficiency of switched memory B cells (CD27+ IgM- IgD-) in subgroups of patients with common variable immunodeficiency: a new approach to classify a heterogeneous disease. Blood. 2002 Mar 1;99(5):1544-1551
2. Brouet JC, Chedeville A, Fermand JP, Royer B: Study of the B cell memory compartment in common variable immunodeficiency. Eur J Immunol. 2000 Sep;30(9):2516-2520
3. Wehr C, Kivioja T, Schmitt C, et al: The EUROclass trial: defining subgroups in common variable immunodeficiency. Blood. 2008 Jan 1;111(1):77-85
4. Alachkar H, Taubenheim N, Haeney MR, et al: Memory switched B-cell percentage and not serum immunoglobulin concentration is associated with clinical complications in children and adults with specific antibody deficiency and common variable immunodeficiency. Clin Immunol. 2006 Sep;120(3):310-318
5. Lee WI, Torgerson TR, Schumacher MJ, et al: Molecular analysis of a large cohort of patients with hyper immunoglobulin M (hyper IgM) syndrome. Blood. 2005 Mar 1;105(5):1881-1890
6. Ramirez NJ, Posadas-Cantera S, Caballero-Oteyza A, Camacho-Ordonez N, Grimbacher B. There is no gene for CVID - novel monogenetic causes for primary antibody deficiency. Curr Opin Immunol. 2021 Oct;72:176-185. doi:10.1016/j.coi.2021.05.010
Method Description
Describes how the test is performed and provides a method-specific reference
Describes how the test is performed and provides a method-specific reference
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+).(Package insert: Ficoll-Hypaque Plus. GE Healthcare Life Sciences; Unpublished Mayo method)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
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.
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.
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.
3 days
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
PBMCs: 7 days
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
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.
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.
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 using an analyte specific reagent. Its performance characteristics were 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.
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.
CPT codes are provided by the performing laboratory.
86356 x7
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.
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 |
|---|---|---|
| RBCS | Relative B Cell Subset Analysis % | 90416-9 |
| 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.
|
|---|---|---|
| BCD19 | CD19+ % of total Lymphocytes | 8117-4 |
| BCD20 | CD20+ % of total Lymphocytes | 8119-0 |
| BCD27 | CD27+ % of CD19+ B Cells | 89358-6 |
| B27MD | CD27+ IgM+ IgD+ % of CD19+ B Cells | 89352-9 |
| B27N | CD27+ IgM- IgD- % of CD19+ B Cells | 89350-3 |
| B27M | CD27+ IgM+ IgD- % of CD19+ B Cells | 89348-7 |
| BIGM | IgM+ % of CD19+ B Cells | 89346-1 |
| B38MN | CD38+ IgM- % of CD19+ B Cells | 89344-6 |
| B38MP | CD38+ IgM+ % of CD19+ B Cells | 89341-2 |
| B21P | CD21+ % of CD19+ B Cells | 89356-0 |
| B21N | CD21- % of CD19+ B Cells | 89355-2 |
| RBCSI | Interpretation | 69048-7 |
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.
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.
Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.
Normal and Abnormal sample reports are provided as references for report appearance.
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.
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.