Test Code LAB1268 B-Cell Phenotyping Profile for Immunodeficiency and Immune Competence Assessment, Blood
Additional Codes
Mayo Test ID |
IABCS |
Performing Laboratory

Useful For
Screening for common variable immunodeficiency (CVID) and hyper-IgM syndromes
Assessing B-cell subset reconstitution after stem cell or bone marrow transplant
Assessing response to B-cell-depleting immunotherapy
Identifying defects in transmembrane activator and calcium modulator and cyclophilin ligand (CAML) interactor (TACI) and B-cell-activating factor receptor (BAFF-R) in patients presenting with clinical symptoms and other laboratory features consistent with CVID
Testing Algorithm
If immune assessment B-cell subsets test is abnormal, then confirmation will be performed at an additional charge.
When multiple specimen types are required to perform a panel of tests, the laboratory will perform the tests for which the appropriate specimen type was received and the laboratory will cancel those for which the appropriate specimen was not received. Please be advised that this may change the degree of interpretation received with the report. If only the refrigerate EDTA sample is received, this test will be canceled and converted to RBCS / Relative B-Cell Subset Analysis Percentage which provides the relative B-cell subset values without quantitation.
Method Name
TBBS: Flow Cytometry
IABC: Fluorescent Flow Cytometry
Reporting Name
Immune Assessment B Cell Subsets, BSpecimen Type
Whole Blood EDTAAdvisory Information
Shipping Instructions
Specimens are required to be received in the laboratory weekdays and by 4 p.m. on Friday. Draw and package specimen as close to shipping time as possible.
It is recommended that specimens arrive within 24 hours of draw.
Specimens arriving on the weekend may be canceled.
Necessary Information
1. Date of draw is required.
2. Ordering physician's name and phone number are required.
Specimen Required
Two separate EDTA specimens are required: 1 refrigerated and 1 at ambient transport temperature.
For serial monitoring, we recommend that specimen draws be performed at the same time of day.
Specimen Type: Whole blood for TBBS / Quantitative Lymphocyte Subsets: T, B, and NK
Container/Tube: 4 mL Lavender top (EDTA)
Specimen Volume: 3 mL
Collection Instructions:
1. Send specimen in original tube. Do not aliquot.
2. Label specimen as blood for TBBS / Quantitative Lymphocyte Subsets: T, B, and NK.
Specimen Stability Information: Ambient <52 hours
Specimen Type: Whole blood for IABC / B-Cell Phenotyping Screen for Immunodeficiency and Immune Competence Assessment, Blood
Container/Tube: Lavender top (EDTA)
Specimen Volume:
≤14 years: 4 mL
>14 years: 10 mL
Collection Instructions:
1. Send specimen in original tube. Do not aliquot.
2. Label specimen as blood for IABC / B-Cell Phenotyping Screen for Immunodeficiency and Immune Competence Assessment, Blood.
Specimen Stability Information: Refrigerated <48 hours
Specimen Minimum Volume
TBBS: 1 mL
IABC
≤14 years: 3 mL
>14 years: 5 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Whole Blood EDTA | Varies | 48 hours |
Reject Due To
Hemolysis |
Mild OK; Gross reject |
Lipemia |
Mild OK; Gross reject |
Icterus |
NA |
Other |
Specimen in aliquot tube (not in original Vacutainer) |
Reference Values
The appropriate age-related reference values will be provided on the report.
Interpretation
Quantitative Lymphocyte Subsets: T, B, and NK :
When the CD4 count falls below 500 cells/mcL, HIV-positive patients can be diagnosed with AIDS and can receive antiretroviral therapy.
When the CD4 count falls below 200 cells/mcL, prophylaxis against Pneumocystis jiroveci pneumonia is recommended.
Immune Assessment B Cell Subsets, Blood:
The assay provides quantitative information on the various B-cell subsets (percentage and absolute counts in cells/microliter). 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 nonswitched 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 low ("immature") B cells
-CD19+ CD21+=mature B cells
-CD19+ CD20+=B cells co-expressing 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 defect in memory 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.
Since each of the 11 B-cell subsets listed above contributes to the diagnosis of common variable immunodeficiency (CVID) and hyper-IgM syndromes and provides further information on the likely specific genetic defect, all the B-cell subsets are carefully evaluated to determine if further testing is needed for confirmation, including functional assays and genotyping, which is then suggested as follow-up testing in the interpretive report as detailed below.
If abnormalities are found in the B-cell phenotyping panel, the specimen will be reflexed to the CVID confirmation panel for assessment of defects in surface expression of B-cell-activating factor receptor (BAFF-R) and transmembrane activator and calcium modulator and cyclophilin ligand (CAML) interactor (TACI) (2 genes/proteins associated with CVID). To conclusively determine if TACI mutations are present, the TACI mutation analysis test by gene sequencing can be ordered (TACIF / Transmembrane Activator and CAML Interactor [TACI] Gene, Full Gene Analysis).
CVID Confirmation Flow Panel:
BAFF-R is normally expressed on over 95% of B cells, while TACI is expressed on a smaller subset of B cells and a proportion of activated T cells.
The lack of TACI or BAFF-R surface expression on the appropriate B-cell population is consistent with a CVID defect.
Results will be interpreted in the context of the B-cell phenotyping results and correlation to clinical presentation will be recommended.
Day(s) and Time(s) Performed
Monday through Friday
Specimens are required to be received in the laboratory on weekdays and by 4 p.m. on Friday. No weekend processing.
Analytic Time
3 daysSpecimen Retention Time
PBMC's are stored for 7 days at -70° CTest Classification
See Individual Test IDsCPT Code Information
T- and B-Cell Quantitation by Flow Cytometry
86355-B cells, total count
86357-Natural killer (NK) cells, total count
86359-T cells, total count
86360-Absolute CD4/CD8 count with ratio
B-Cell Phenotyping Screen for Immunodeficiency and Immune Competence Assessment, Blood
88184-Flow cytometry, first marker
88185 x 7-Flow cytometry, each additional marker
Common Variable Immunodeficiency Confirmation Flow Panel
88184-Flow cytometry, first marker (if appropriate)
88185 x 2-Flow cytometry, each additional marker (if appropriate)
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
IABCS | Immune Assessment B Cell Subsets, B | 90416-9 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
30296 | CD19+ % of total Lymphocytes | 8117-4 |
3321 | CD45 Total Lymph Count | 27071-0 |
3316 | % CD3 (T Cells) | 8124-0 |
29094 | CD20+ % of total Lymphocytes | 8119-0 |
3322 | CD3 (T Cells) | 8122-4 |
30298 | CD27+ % of CD19+ B cells | 89358-6 |
3319 | % CD4 (T Cells) | 8123-2 |
30300 | CD27+ IgM+ IgD+ % of CD19+ B cells | 89352-9 |
3325 | CD4 (T Cells) | 24467-3 |
30302 | CD27+ IgM- IgD- % of CD19+ B cells | 89350-3 |
3320 | % CD8 (T Cells) | 8101-8 |
30304 | CD27+ IgM+ IgD- % of CD19+ B cells | 89348-7 |
3326 | CD8 (T Cells) | 14135-8 |
30306 | IgM+ % of CD19+ B cells | 89346-1 |
3318 | % CD19 (B Cells) | 8117-4 |
30308 | CD38+ IgM- % of CD19+ B cells | 89344-6 |
30310 | CD38+ IgM+ % of CD19+ B cells | 89341-2 |
3324 | CD19 (B Cells) | 8116-6 |
4054 | % CD16+CD56 (NK cells) | 8112-5 |
30312 | CD21+ % of CD19+ B cells | 89356-0 |
30314 | CD21- % of CD19+ B cells | 89355-2 |
4055 | CD16+CD56 (NK cells) | 20402-4 |
3327 | 4/8 Ratio | 54218-3 |
30297 | CD19+ | 8116-6 |
29095 | CD20+ | 9558-8 |
6657 | Comment | 48767-8 |
30299 | CD27+ | 89353-7 |
30301 | CD27+ IgM+ IgD+ | 89351-1 |
30303 | CD27+ IgM- IgD- | 89349-5 |
30305 | CD27+ IgM+ IgD- | 89347-9 |
30307 | IgM+ | 89345-3 |
30309 | CD38+ IgM- | 89343-8 |
30311 | CD38+ IgM+ | 89357-8 |
30313 | CD21+ | 25164-5 |
30315 | CD21- | 89354-5 |
30316 | Interpretation | 69048-7 |
Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
TBBS | QN Lymphocyte Subsets: T, B, and NK | Yes | Yes |
IABC | Immune Assessment B Cell Subsets, B | No | Yes |
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
CVID | CVID Confirmation Flow Panel | Yes | No |