Name |
T-Cell Quantitiation by Flow Cytometry |
Alternative name/Profile |
Lymphocyte subsets, T-Cell Subsets, CD3 Count, CD4 Count, CD8 Count, Helper-T count, Cytotoxic-T Count, Helper T-Cells, Cytotoxic T-Cells, Lymphocyte Ratio, Immunodeficiency, HIV, Immunophenotyping, AIDS (Acquired Immune Deficiency Syndrome), T Cell, T Cells, LSS |
Department |
Immunology |
Investigation |
Flow Cytometry (BD FACSCanto II) |
Specimen type |
Blood |
Sample type |
EDTA (Blood) |
Sample container & volume |
4ml Purple EDTA |
Frequency of analysis |
Daily Monday to Friday |
Turnaround time |
2 days |
Availability |
|
Notes |
Useful for:
- Monitoring the Helper T-Cell (CD4) Count in patients diagnosed with HIV.
- Investigating patients with Primary Immunodeficiency. This includes SCID (Severe Combined Immunodeficiency).
- Immune monitoring in patients recieving immunosupressive therapy.
- Assessment of immune reconstitution post hematopoietic cell transplantation.
- Investigation of anomalies in lymphocyte subsets due to infection or malignancy.
Clinical Information:
- Lymphocytes can be generally classified into T-, B- and Natural Killer (NK-) cells which can be distinguished, by flow cytometry, using a combination of one or more cell surface markers.
- T- Cells can be further subdivided into two groups - Helper T-Cells and Cytotoxic T-Cells.
- T-Cells are detected using the surface marker CD3, while Helper T-Cells and Cytotoxic T-Cells are detected using CD4 and CD8 respectively.
- Biological factors such as temperature, hormones, circadian variation and the environment can influence absolute lymphocyte levels. It is accepted that in general Helper T-Cell (CD4) levels are lower in the morning than in the evening and that Cytotoxic T-Cells (CD8) are higher in the morning than in the evening.
Please Note:
- Where External Institiutions cannot guarantee immediate delivery, samples must be kept at room temperature until they are transported to St. James's Hospital for processing.
- As absolute lymphocyte levels are influenced by circadian variation, consistency of timing when aquiring blood samples is required when monitoring patients serially.
- The request 'Lymphocyte Subsets' only provides T-Cell quantitation. If B-Cell and Natural Killer (NK) cell quantitiation is required the request 'TBNK' should be used, or this must be specified on the form.
- Samples must be kept at ambient room temperature and analysed within 24 hours of sample collection.
- The cut-off time for receipt of samples is 15.00.
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Related links |
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Reference range |
| |
Total T-Cells (CD3)
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Helper T-Cells (CD4)
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Cytotoxic T-Cells (CD8)
|
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Age
|
Percentage (%)
|
Absolute Count (x10^6/L)
|
Percentage (%)
|
Absolute Count (x10^6/L)
|
Percentage (%)
|
Absolute Count (x10^6/L)
|
|
0-3 Months
|
53-84
|
2500-5500
|
35-64
|
1600-4000
|
12-28
|
560-1700
|
|
3-6 Months
|
51-77
|
2500-5600
|
35-56
|
1800-4000
|
12-23
|
590-1600
|
|
6-12 Months
|
49-76
|
1900-5900
|
31-56
|
1400-4300
|
12-24
|
500-1700
|
|
1-2 Years
|
53-75
|
2100-6200
|
32-51
|
1300-3400
|
14-30
|
620-2000
|
|
2-6 Years
|
56-75
|
1400-3700
|
28-47
|
700-2200
|
16-30
|
490-1300
|
|
6-12 Years
|
60-76
|
1200-2600
|
31-47
|
650-1500
|
18-35
|
370-1100
|
|
12-18 Years
|
56-84
|
1000-2200
|
31-52
|
530-1300
|
18-35
|
330-920
|
|
Adult
|
66-85
|
797-2996
|
35-60
|
502-1749
|
18-49
|
263-1137
|
Adult Reference Ranges validated in-house 2012.
Paediatric Ranges adopted from Shearer WT, Rosenblatt HM, Gelman RS et al. Lymphocyte subsets in 817 healthy children from birth through 18 years of age: The Paediatric AIDS Clinical Trials Group P1009 study, J. Allergy Clinical Immunology 2003; 112(5): 973-980. |
Last updated |
Fri, 10 Apr 2020 08:49:58 IST |
