Acquired Immune Deficiency Syndrome CD4+ Count

Abstract

For decades, the CD4 cell count measurement has been used to understand the progression of the human immunodeficiency virus (HIV) disease. HIV is a fatal infection, characterized by the targeting and destruction of CD4 T lymphocytes in the peripheral blood. CD4 T lymphocytes are a part of the human T-lymphocyte cells that are produced in the bone marrow and eventually mature in the thymus. They circulate the body to fight against bacteria, viruses, and other organisms. If HIV goes untreated, the virus enters the cell and replicates, which eventually causes CD4 cells to die. The remaining infected cells release virions, which infect other cells, leading to the progression of the disease. The loss of CD4 T lymphocytes will result in the inability to have a proper immune response.CD4 cell count is a laboratory test that measures the number of CD4 T-cells. The normal range is between 500 to 1500 cells/mm^3. Clinicians use this test to monitor the destruction of CD4 cells, and it also monitors the effectiveness of the antiretroviral treatment (ART). For a physician, the CD4 cell count has become the best indicator of disease progression and is used to stage disease and guide medical therapy. Per the Center for Disease Control and Prevention (CDC), one of the indications for the diagnosis of AIDS is when CD4 cell count drops below 200 cells/mm^3. The decline of CD4 T cells can lead to opportunistic infections, and it increases mortality.

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