Elderly people with HIV/AIDS have fewer lesions of Alzheimer's disease in their brains than their HIV-negative peers, new findings presented at Touro College Research Day show.
"The frequency of Alzheimer-type changes in the brains of aging patients with chronic HIV infection and/or AIDS is lower than in the brains of normal, non-HIV infected patients," said Dr. Piotr Kozlowski, MD, the study's lead author and Dean of Research at Touro College of Osteopathic Medicine.
Dr. Kozlowski and his colleagues studied brain tissue from 56 people with AIDS and from 15 HIV-negative individuals. They obtained the brain tissue samples from the National NeuroAIDS Tissue Consortium, a network of four clinical sites across the United States that bank tissue from people with HIV as well as healthy individuals.
More study is needed to determine why the brains of the HIV patients seemed to have less Alzheimer's disease, he added, but suggested that the immune system abnormalities in HIV may impact how the disease manifests itself in the brain. Abnormalities in microglia, immune cells that reside in the brain and cells that are targets for HIV and, could be responsible for the surprisingly low level of plaques and tangles in the HIV patients' brains, Dr. Kozlowski said.
He and his colleagues are planning to examine more brain specimens, from both very old and younger patients, both microscopically and at the molecular level, to learn more about the interplay between HIV infection and Alzheimer's disease.