A decrease in which type of cells is most closely associated with a heightened risk of opportunistic infections in AIDS?

The heightened risk of opportunistic infections in AIDS is closely associated with a decrease in CD4 T cells. CD4 T cells, also known as helper T cells, play a crucial role in the immune system by coordinating the immune response. They assist in activating other immune cells such as CD8 T cells and B cells, which are essential for fighting infections.

In the context of AIDS, which is caused by the Human Immunodeficiency Virus (HIV), the virus specifically targets and destroys CD4 T cells. As the number of these cells decreases, the body becomes increasingly unable to mount an effective immune response. This leads to a state of immunodeficiency, making individuals more susceptible to infections that would normally be controlled by a healthy immune system.

Opportunistic infections are those that take advantage of the weakened immune defenses, and individuals with fewer CD4 T cells are at a significantly higher risk of developing these types of infections. Therefore, monitoring the levels of CD4 T cells is vital in managing patients with HIV/AIDS to prevent and treat opportunistic infections effectively.