What results in the progression from HIV to AIDS?

The progression from HIV to AIDS is characterized by the development of certain complications primarily due to the immune system's inability to fend off infections. The presence of one or more opportunistic infections is a critical criterion for defining AIDS. Opportunistic infections are those that take advantage of weakened immune systems, which is a hallmark of AIDS. In the context of HIV, when the CD4 T-cell count falls below a certain threshold or when specific opportunistic infections occur, the diagnosis of AIDS is confirmed.

Opportunistic infections can include illnesses such as pneumocystis pneumonia, tuberculosis, and various fungal infections that would not usually cause disease in individuals with a healthy immune response. Therefore, the presence of these infections signifies a significant impairment of the immune system typically associated with advanced HIV disease.

On the other hand, having a high CD4 cell count alone does not indicate progression to AIDS, nor does the presence of symptoms or the levels of plasma cells without concurrent opportunistic infections. The diagnosis hinges on the occurrence of these infections or specific clinical indicators that reflect an advanced stage of HIV infection. Thus, the correct answer regarding the progression from HIV to AIDS is indeed the presence of one or more opportunistic infections.