How does HIV affect the immune system?

HIV specifically targets the immune system by attacking and destroying CD4 T cells, which play a crucial role in coordinating the immune response. CD4 T cells are vital for the immune system's ability to function effectively, as they help activate other immune cells, including B cells and cytotoxic T cells, to fight off infections. When HIV infects these cells, it leads to a decline in their numbers over time, ultimately compromising the body’s ability to mount an effective immune response. This makes individuals more vulnerable to opportunistic infections and certain cancers, as their immune system becomes less able to recognize and combat these threats. As such, the primary pathology of HIV lies in its effects on the immune system, emphasizing the importance of monitoring CD4 counts in individuals living with HIV to assess their immune health and guide treatment.