Which disease is caused by the human immunodeficiency virus (HIV) and affects the immune system?

The disease caused by the human immunodeficiency virus (HIV) that primarily affects the immune system is Acquired Immune Deficiency Syndrome (AIDS). HIV attacks and destroys specific cells in the immune system, particularly CD4 T-lymphocytes, which are critical for coordinating the immune response. As the infection progresses and more of these cells are lost, the body becomes increasingly vulnerable to various infections, diseases, and certain cancers that it would normally be able to fight off.

AIDS is the final stage of HIV infection, diagnosed when the immune system is severely compromised, and individuals are at risk for opportunistic infections and conditions associated with the decline in immune function. This distinguishing factor makes AIDS the specific answer to the question regarding a disease linked to HIV and the immune system. Other diseases mentioned, such as cancer, hepatitis, and Lyme disease, do not have a direct relation to HIV and do not primarily result from its effects on the immune system.