CD4+ T-Cell counting Technology
What are CD4 T-cells?
CD4+ T-cells are also known as helper T-cells and act as an co-ordinator of the immune response, unfortunately, CD4+ T-cells are also the main targets of HIV. HIV destroys infected CD4+ T-cells and leading to an overall weakening of the immune system.
What is the CD4+ T-cell count?
Lower numbers of circulating CD4+ T-cells indicates a weakening of the immune system and advancement in the progression of HIV disease. The CD4+ T-cell count can also be indicative of the success or failure of anti-retroviral therapy (ARV).
How are CD4+ T-cells enumerated?
CD4+ T-cell counts are performed using manual and automated methods.
- Optical or fluorescence microscopy
- Requires a centrifuge and other laboratory consumables e.g. beads
- Designed for low sample throughput laboratories in resource-limited settings
- Currently marketed products include; Cyto-Spheres [Coulter Corporation, USA] and Dynabeads® [Dynal Biotech, Norway]
- Gold Standard for accuracy, precision, reproducibility
- Expensive and technically demanding, requiring extensive technician training
- Capable of high sample throughput in well-resourced laboratory
- Can be used for other laboratory applications
- Requires regular equipment maintenance
- Cytometer used exclusively to perform CD4+ and CD8+ T-cell enumeration
- Simpler and cheaper than flow cytometers but lacking in general laboratory versatility
- Currently marketed products include; FACSCount™ [Becton Dickinson, USA]