HIV-associated Dementia Linked to Proviral DNA Levels

By David Douglas

Levels of circulating proviral HIV DNA appear to be elevated in patients with HIV-associated dementia (HAD), researchers report in the January 3rd issue of AIDS.

Lead investigator Dr. Bruce Shiramizu told Reuters Health that "HAD and milder forms of neurocognitive disorders continue to be seen despite effective treatment which lowers HIV-1 RNA levels. Because monocytes/macrophages are cells that continue to harbor the virus, in spite of effective therapy, our group was interested to see if proviral DNA in these cells is associated with HAD."

Dr. Shiramizu of the University of Hawaii, Honolulu, and colleagues compared HIV DNA levels within circulating leukocytes in 27 HIV patients with HAD and 22 HIV patients with normal cognition.

Those with HAD had considerably higher levels of circulating proviral DNA. Analysis of a subset of 11 HAD patients and 13 with normal cognition, all of whom had undetectable viral load, showed that the odds ratio for HAD attributable to HIV DNA copy number was 2.76.

Findings in a subset of 5 patients indicated that activated macrophages/monocytes were the primary source of HIV DNA.

"Further studies," Dr. Shiramizu continued, "are being conducted to confirm that more virus is found in macrophages/monocytes. If confirmed, then this may have implications in developing strategies to target macrophages/monocytes with HIV DNA to prevent HAD."

02/11/05

AIDS 2005;19:45-52.