AIDS Dementia Complex - Research

Research

AIDS Dementia Complex (ADC) is not a true opportunistic infection; it is one of the few conditions caused directly by HIV itself. However, the etiology of ADC can be difficult to discern because the central nervous system can be damaged by a number of other causes related to HIV infection:

• opportunistic infections
• Primary cerebral lymphoma or metastasis of other AIDS-related cancers
• direct effects of HIV in the brain
• toxic effects of drug treatments
• malnutrition

Many researchers believe that HIV damages the vital brain cells, neurons, indirectly. According to one theory, HIV either infects or activates cells that nurture and maintain the brain, known as macrophages and microglia. These cells then produce toxins that can set off a series of reactions that instruct neurons to kill themselves. The infected macrophages and microglia also appear to produce additional factors such as chemokines and cytokines that can affect neurons as well as other brain cells known as astrocytes. The affected astrocytes, which normally nurture and protect neurons, also may now end up harming neurons. HIV protein gp120 inhibits the stem cells in the brain from producing new nerve cells. In the neuronal cells, the HIV gp120 induces mitochondrial-death proteins like caspases which may influence the upregulation of the death receptor Fas leading to apoptosis. Researchers hope that new drugs under investigation will interfere with the detrimental cycle and prevent neuron death.