Which disease is characterized by a weakened immune system due to HIV?

The disease that is characterized by a weakened immune system due to HIV is AIDS, which stands for Acquired Immunodeficiency Syndrome. HIV, or Human Immunodeficiency Virus, attacks the immune system, primarily targeting CD4 cells (T cells) that are essential for fighting off infections. As the virus progresses, it leads to a significant decrease in these cells, resulting in the individual developing AIDS. At this advanced stage, the immune system becomes severely compromised, making it difficult for the body to combat opportunistic infections and certain cancers.

The other diseases mentioned, while serious in their own right, do not derive from a weakened immune response due to HIV. Cancer can be affected by a compromised immune system, but it is not a direct result of HIV infection. Diabetes is a metabolic disease related to insulin regulation, and Alzheimer's is a neurodegenerative disorder affecting cognitive function. None of these directly relate to the immune system's functionality in the context of HIV and AIDS specifically.