B-Cell CD20 Expression by Flow Cytometry, Quantitative
Also known as: CD20 QUANT
Use
This test is used to enumerate B cells in peripheral blood or monitor response to rituximab therapy in patients with autoimmune disorders. It is particularly useful in evaluating B-cell suppression following rituximab treatment. For assessing primary B-cell deficiency conditions, such as agammaglobulinemia or common variable immunodeficiency (CVID), a B Cell Subset Analysis is recommended.
Special Instructions
This assay detects low levels of B cells and provides quantitative cell numbers in rituximab-treated patients by using both CD20 and CD19 markers. Ensure relevant clinical history, differential diagnosis, and pathology reports are provided.
Limitations
The test's performance characteristics were determined by ARUP Laboratories but it has not been cleared or approved by the FDA. Specimen viability is crucial for accurate results; clotted, hemolyzed, or frozen specimens are unacceptable. Specimens received more than 72 hours post-collection may also yield unreliable results.
New York Approved
Methodology
Cell-based / Cytometry (Flow Cytometry)
Biomarkers
LOINC Codes
- 8117-4
- 8116-6
- 94689-7
- 9558-8
- 33193-4
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
5 mL
Minimum Volume
1 mL
Container
Green (sodium heparin). Also acceptable: lavender (EDTA) or pink (K2EDTA).
Storage Instructions
Specimen should be received within 72 hours of collection for optimal viable testing.
Causes for Rejection
Clotted, hemolyzed, or frozen specimens. Specimens received more than 72 hours from collection.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 72 hours |
| Frozen | Unacceptable |