Extended B Cell Panel
Test Code
XBCP
Samples accepted Monday - Thursday, no later than noon on Thursday. Samples must arrive within 24 hours of collection.
Description
This test measures subsets of B lymphocytes using indirect immunofluoresence staining with monocloanal antibodies followed by analysis by flow cytometry. The test is useful for the assessment of B cell subsets in immunodeficiency.
Combined variable immunodeficiency (CVID) is a heterogeneous group of disorders characterized by hypogammaglobulinemia, antibody deficiency and recurrent bacterial infections. CVID may develop due to defects in either T or B cells, leading to perturbations in B cell numbers, memory B cell populations and the maturation state of B cells. Detailed analysis of B cell populations assists not only with comprehensive phenotyping of CVID patients but may also provide insight into possible genetic defects.
Collect
Draw one green top tube (Sodium or Lithium Heparin).
Patient Prep
Preferred volume: 6 mL blood
Pediatric Collection
Minimum volume: 6 mL blood
Unacceptable Conditions
Frozen, clotted, hemolyzed or centrifuged specimens. Anticoagulants other than heparin. Specimens >24 hours old.
Storage Transport Temp
Maintain and transport specimens at room temperature (18-22°C).
Ship specimens Priority Overnight via Fed Ex in container sufficiently insulated to avoid temperature extremes (<10°C and >37°C).
Stability
24 hours at room temperature
Notes
Samples must be received within 24 hours of draw. Samples are accepted Monday through noon on Thursday.
Reference Interval
| Analyte(s) | Markers | Adult Reference Range (% of CD20 B cells) |
| Immature B cells | CD21-/CD38- | 0.5 – 8.0 |
| Transitional B cells | CD38+/IgM+ | 0.3 – 9.2 |
| Plasmablasts | CD38+/IgM- | 0.1 -4.7 |
Interpretation
This test provides analysis of immature and transitional B cells as well as plasma cells. This information is used in the evaluation of common variable immunodeficiency (CVID).
CPT Code
88184 x 3, 88185
New York Approved
No: Run with Waiver
FDA
LDT