Which bloodborne disease attacks and destroys CD4 cells, leading to immunocompromised states?

The disease that specifically attacks and destroys CD4 cells in the immune system is Human Immunodeficiency Virus (HIV). CD4 cells, also known as T-helper cells, play a critical role in orchestrating the immune response. When HIV infects these cells, it uses them to replicate, ultimately leading to a significant reduction in their numbers. This deterioration compromises the immune system, making the individual more susceptible to opportunistic infections and certain cancers, which characterizes the progression to Acquired Immunodeficiency Syndrome (AIDS).

In contrast, the other diseases listed do not have this specific mechanism of action. Hepatitis B and C primarily affect the liver and are transmitted through blood and body fluids, but they do not specifically target CD4 cells. Syphilis is a bacterial infection that affects various body systems but does not destroy CD4 cells. Therefore, understanding the unique impact of HIV on the immune system highlights why it is the correct answer to the question.