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HelpTest Code CD20B CD20 on B Cells, Blood
Reporting Name
CD20, B-CellsUseful For
Evaluation of patients with a suspected CD19 deficiency (humoral immunodeficiency)
Confirming complete absence of B cells in suspected primary humoral immunodeficiencies using both CD19 and CD20 markers
Assessing therapeutic B-cell depletion quantitatively (absolute counts of cells/mcL) in any clinical context, including malignancies, autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, and membranous glomerulonephritis among others, and treatment or prevention of acute humoral rejection in positive crossmatch renal transplant recipients
This test is not useful for assessing whether B cells express the target molecule (CD20) in the context of initiating therapeutic monoclonal anti-CD20 antibody therapy (rituximab, ofatumumab, and tositumomab) for any of the hematological malignancies, or in other clinical contexts, such as autoimmunity.
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Whole Blood EDTAOrdering Guidance
This is the correct test to order if specifically confirming the absence of B cells due to suspected primary humoral or combined immunodeficiency or evaluating for CD19 deficiency.
If desirous of only quantitatively measuring total CD19 or CD20+ B cells, order TBBS / Quantitative Lymphocyte Subsets: T, B, and Natural Killer (NK) Cells, Blood or CD20B / CD20 on B Cells, Blood, respectively. Do not order the detailed analysis of B cell subsets for this purpose.
This test should not be ordered for a comprehensive evaluation of peripheral B-cell subsets. For evaluation of memory B-cell subsets, transitional B cells, mature and immature B cells, order IABCS / B-Cell Phenotyping Profile for Immunodeficiency and Immune Competence Assessment, Blood.
This test should not be used for evaluating presence of CD20 on malignant or nonmalignant B cells. The following test should be ordered instead, CEE20 / CD20 Cell Expression Evaluation, Varies.
Shipping Instructions
Collect and package specimens as close to shipping time as possible.
It is recommended that specimens arrive within 24 hours of collection.
Necessary Information
Date and time of collection is required.
Specimen Required
Container/Tube: Lavender top (EDTA)
Specimen Volume: 3 mL
Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.
Additional Information:
1. Secondary aliquot tubes will be rejected.
2. Testing will be canceled if the specimen is not received ambient.
3. For serial monitoring, it is recommended that specimens are collected at the same time of day.
Specimen Minimum Volume
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole Blood EDTA | Ambient | 4 days | PURPLE OR PINK TOP/EDTA |
Reference Values
%CD19 B Cells
≥19 years: 4.6-22.1%
CD19 Absolute
≥19 years: 56.6-417.4 cells/mcL
%CD20 B Cells
≥19 years: 5.0-22.3%
CD20 Absolute
≥19 years: 74.4-441.1 cells/mcL
CD45 Absolute
18-55 years: 0.99-3.15 thou/mcL
>55 years: 1.00-3.33 thou/mcL
Day(s) Performed
Monday through Sunday
Resulted Monday through Friday
Test Classification
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
86355
86356
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| CD20B | CD20, B-Cells | 100994-3 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 89584 | CD45 Absolute | 27071-0 |
| 29579 | %CD19 B-Cells | 8117-4 |
| 29580 | %CD20 B-Cells | 8119-0 |
| 29581 | CD19 Absolute | 8116-6 |
| 29582 | CD20 Absolute | 9558-8 |
| 29583 | Comment | 48767-8 |
Interpretation
The presence of CD20+ B cells with corresponding absence of CD19 staining in individuals not receiving anti-CD20 monoclonal antibody treatment or with clinical features of variable primary humoral immunodeficiency may suggest an underlying CD19 deficiency which should be further evaluated.
Absence of both CD20 and CD19 markers on B cells in blood from individuals not on anti-CD20 monoclonal antibody treatment is consistent with complete mature and immature peripheral B-cell depletion, which may be due to an underlying primary immunodeficiency.
Patients receiving B-cell depleting therapy with anti-CD20 antibodies can show unusual populations of B cells on reconstitution that express either CD19 or CD20 due to a phenomenon known as trogocytosis.
Clinical Reference
1. Nadler LM, Ritz J, Hardy R, Pesando JM, Schlossman SF, Stashenko P. A unique cell-surface antigen identifying lymphoid malignancies of B-cell origin. J Clin Invest. 1981;67(1):134
2. Robillard N, Avet-Loiseau H, Garand R, et al. CD20 is associated with a small mature plasma cell morphology and t(11;14) in multiple myeloma. Blood. 2003;102(3):1070-1071
3. Pescovitz MD. Rituximab, an anti-CD20 monoclonal antibody: history and mechanism of action. Am J Transplant. 2006;6(5 Pt 1):859-866
4. van Zelm MC, Reisli I, van der Burg M, et al. An antibody-deficiency syndrome due to mutations in the CD19 gene. N Engl J Med. 2006;354(18):1901-1912
5. Kuijpers TW, Bende RJ, Baars PA, et al. CD20 deficiency in humans results in impaired T cell-independent antibody responses. J Clin Invest. 2010;120(1):214-222. doi:10.1172/JCI40231
6.Carmichael KF, Abayomi A. Analysis of diurnal variation of lymphocyte subsets in healthy subjects and its implication in HIV monitoring and treatment. 15th International Conference on AIDS, Bangkok, Thailand, 2004, Abstract B11052
7. Dimitrov S, Benedict C, Heutling D, Westermann J, Born J, Lange T. Cortisol and epinephrine control opposing circadian rhythms in T-cell subsets. Blood. 2009;113(21):5134-5143
8. Dimitrov S, Lange T, Nohroudi K, Born J. Number and function of circulating antigen presenting cells regulated by sleep. Sleep. 2007;30(4):401-411
9. Kronfol Z, Nair M, Zhang Q, Hill EE, Brown MB. Circadian immune measures in healthy volunteers: relationship to hypothalamic-pituitary-adrenal axis hormones and sympathetic neurotransmitters. Psychosom Med. 1997;59(1):42-50
10. Malone JL, Simms TE, Gray GC, Wagner KF, Burge JR, Burke DS. Sources of variability in repeated T-helper lymphocyte counts from HIV 1-infected patients: total lymphocyte count fluctuations and diurnal cycle are important. J Acquir Immune Defic Syndr (1988). 1990;3(2):144-151
11. Paglieroni TG, Holland PV. Circannual variation in lymphocyte subsets, revisited. Transfusion. 1994;34(6):512-516
12. Engel ER, Walter JE. Rituximab and eculizumab when treating nonmalignant hematologic disorders: infection risk, immunization recommendations, and antimicrobial prophylaxis needs. Hematology Am Soc Hematol Educ Program. 2020;2020(1):312-318. doi:10.1182/hematology.2020000171
13. Cree BAC, Kim HJ, Weinshenker BG, et al. Safety and efficacy of inebilizumab for the treatment of neuromyelitis optica spectrum disorder: end-of-study results from the open-label period of the N-MOmentum trial Lancet Neurol. 2024;23(6):588-602. doi:10.1016/S1474-4422(24)00077-2
Report Available
Same day/1 to 3 daysMethod Name
Flow Cytometry