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How do HIV infections affect lymphocytes and the immune response?

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blood analysis The physical and chemical properties of a sample of blood are examined during blood analysis. The examination of blood is important for the accurate diagnosis of disease.

HIV primarily targets and destroys helper T lymphocytes, also known as CD4+ T cells, which are essential for coordinating the immune system.21

Impact on Immune Response

Helper T cells act as the central regulators of the immune response by producing factors that activate other critical immune cells, including:
* B lymphocytes: Responsible for producing antibodies to fight infections.23
* Cytotoxic T lymphocytes: Tasked with killing cells infected by viruses.23
* Macrophages: Effector cells that attack invading pathogens.2

By infecting and killing these helper T cells, HIV cripples the body's ability to mount an effective defense, leading to acquired immune deficiency syndrome (AIDS).21

Blood Analysis and Monitoring

In the context of blood analysis, physicians monitor the progression of HIV infection using two primary metrics:
* CD4 Count: This measures the number of helper T cells in the blood. A declining count indicates a weakening immune system, with levels falling below 200 cells per microliter typically signaling the onset of AIDS.24
* Viral Load: This measures the amount of virus in the bloodstream, providing an indication of how rapidly the virus is replicating and destroying immune cells.2