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HelpOrder Code CD40 B-Cell CD40 Expression by Flow Cytometry, Blood
Reporting Name
CD40 by Flow, QL, BUseful For
Evaluating patients for hyper-IgM type 3 (HIGM3) syndrome due to defects in CD40, typically seen in patients less than 10 years
Assessing B-cell immune competence in other clinical contexts, including autoimmunity, malignancy, and transplantation
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Whole Blood EDTAOrdering Guidance
This test is not used to detect in CD40L expression (CD154), which is responsible for X-linked hyper-IgM syndrome (HIGM1); see XHIM / X-Linked Hyper IgM Syndrome, Blood.
Shipping Instructions
Testing performed Monday through Friday. Specimens not received by 4pm (CST) on Friday may be cancelled.
Collect and package specimen as close to shipping time as possible. It is recommended that specimens arrive within 24 hours of collection.
Samples arriving on the weekend and observed holidays may be canceled.
Necessary Information
Ordering healthcare professional name and phone number are 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: 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 | 72 hours | PURPLE OR PINK TOP/EDTA |
Reference Values
Present (normal)
Day(s) Performed
Monday through Friday
CPT Code Information
88184
Method Description
The assay involves a multicolor panel of antibodies for the following markers: CD45, CD19, and CD40. After staining, the red blood cells are lysed. The remaining cells are washed and analyzed by flow cytometry. The cell surface expression of CD40 in B cells (CD19+) is determined and expressed as being present or absent.(Unpublished Mayo method)
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
Method Name
Flow Cytometry
Genetics Test Information
Homozygous variants in the CD40 gene cause autosomal recessive hyper-IgM syndrome type 3. The CD40 gene is located on chromosome 20q12-q13.2.