B-Cell CD40 Expression by Flow Cytometry, Blood
Use
This test is useful for evaluating patients suspected of having hyper-IgM type 3 (HIGM3) syndrome, which is associated with defects in the CD40 gene. The test can also assess B-cell immune competence in various clinical settings, such as autoimmunity, malignancy, and transplantation. Homozygous variants in the CD40 gene cause autosomal recessive hyper-IgM syndrome type 3, which is typically observed in patients younger than 10 years. It is vital for distinguishing between forms of hyper-IgM syndrome due to differing prognoses and potential treatment options, such as intravenous IgG and hematopoietic cell transplantation.
Special Instructions
Not provided.
Limitations
The assay does not detect CD40L expression (CD154), which is responsible for X-linked hyper-IgM syndrome. Therefore, for X-linked hyper-IgM syndrome assessment, a different test should be selected. Testing is dependent on proper specimen handling and transport conditions; delays beyond 24 hours from collection to lab receipt can lead to specimen rejection.
New York Approved
Methodology
Cell-based / Cytometry (Flow Cytometry)
Biomarkers
CD40
Protein
LOINC Codes
- 104694-5 - CD40 Cells Bld Ql FC
- 104694-5 - CD40 Cells Bld Ql FC
Result Turnaround Time
3-4 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
3 mL
Minimum Volume
1 mL
Container
Lavender top (EDTA)
Collection Instructions
Send whole blood specimen in original tube. Do not aliquot. For serial monitoring, collect specimens at the same time of day.
Storage Instructions
Ambient for 72 hours.
Causes for Rejection
Gross hemolysis, gross lipemia
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |