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HelpTest Code Epic LAB342 CD4 Count for Immune Monitoring, Blood
Additional Codes
SQ code CD4TM
Mayo code TCD4
Reporting Name
CD4 T-Cell CountSpecimen Type
Whole Blood EDTAPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Useful For
Serial monitoring of CD4 T cell count in patients who are HIV-positive
Follow-up and diagnostic evaluation of primary cellular immunodeficiencies, including severe combined immunodeficiency
T-cell immune monitoring following immunosuppressive therapy for transplantation, autoimmunity, and other immunological conditions where such treatment is utilized
Assessment of T-cell immune reconstitution post hematopoietic cell transplantation
Early screening of gross quantitative anomalies in T cells in infection or malignancies
This assay should not be used for diagnosing T-lymphocytic malignancies or evaluation of T-cell lymphocytosis of unknown etiology.
Ordering Guidance
For diagnosing T-lymphocytic malignancies or evaluation of T-cell lymphocytosis of unknown etiology, order LCMS / Leukemia/Lymphoma Immunophenotyping, Flow Cytometry, Varies, which includes a hematopathology review.
Shipping Instructions
It is recommended that specimens arrive within 24 hours of collection. Collect and package specimen as close to shipping time as possible.
Necessary Information
Date 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: For serial monitoring, it is recommended that specimen collection be performed 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
The appropriate age-related reference values will be provided on the report.
Day(s) Performed
Monday through Sunday
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
86359-T cells, total count
86360-Absolute CD4/CD8 count with ratio
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| TCD4 | CD4 T-Cell Count | 80721-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 3321 | CD45 Total Lymph Count | 27071-0 |
| 3316 | % CD3 (T Cells) | 8124-0 |
| 3322 | CD3 (T Cells) | 8122-4 |
| 3319 | % CD4 (T Cells) | 8123-2 |
| 3325 | CD4 (T Cells) | 24467-3 |
| 3320 | % CD8 (T Cells) | 8101-8 |
| 3326 | CD8 (T Cells) | 14135-8 |
| 3327 | 4/8 Ratio | 54218-3 |
| CMTTC | Comment | 69052-9 |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
Method Name
Flow Cytometry
Method Description
The T cell surface marker assay uses monoclonal antibodies to identify the various membrane antigens, and flow cytometry to enumerate the number of cells expressing these differentiation antigens. CD14 is used to exclude monocytes, thereby improving accuracy and enhancing the purity of the lymphocyte population. The results are reported as the percent of lymphocytes that are total T cells (CD3+), CD3+CD4+ T cells, and CD3+CD8+ T cells, along with the absolute number of each cell type per microliter of blood. The assay is a 5-color, no-wash procedure and the absolute counts are calculated from internal bead standards. The total CD45+ lymphocyte count (reported as thousand cells per microliter) and the CD4:CD8 ratio are also reported.(Hoffman RA, Kung PC, Hansen WP, Goldstein G. Simple and rapid measurement of human T lymphocytes and their subclasses in peripheral blood. Proc Natl Acad Sci USA. 1980;77(8):4914-4917; Mandy FF, Nicholson JK, McDougal JS. CDC. Guidelines for performing single-platform absolute CD4+ T-cell determinations with CD45 gating for persons infected with human immunodeficiency virus. Centers for Disease Control and Prevention. MMWR Recomm Rep. 2003;52[RR-2]:1-13)