HIV in the nervous system – still a cause for concern?

HIV infection can be controlled with antiretroviral drugs, but it cannot be wiped out. New evidence suggests that low levels of HIV may still lead to long-term brain damage and dementia, scientists heard today (Tuesday 09 April 2002) at the spring meeting of the Society for General Microbiology at the University of Warwick.

“There is concern for the longer term outlook of treated patients because of the likely presence of a low grade inflammation of the brain. Infected drug users are at greater risk because of complications from drug-related brain injury, which can lead to premature nerve cell damage,” says Professor Jeanne Bell of Edinburgh University.

Before the introduction of highly active antiretroviral therapy (HAART) HIV related disease of the central nervous system (CNS) was common in late stage disease leading to dementia and HIV encephalitis (HIVE). HIV experts fear the CNS may serve as a hiding place for the virus to evade eradication by HAART.

Professor Bell explains, “Studies in Edinburgh have found that HIVE is more common in drug users compared to homosexual HIV-positive patients. Drug use induces activation of microglial cells in the brain, which may make the CNS more vulnerable to HIV.”

HIV infection of the brain is still a significant cause of disease and death. “This research, funded by the UK MRC and the US NIH, may help prevent possible long-term complications of brain in patients taking combination drugs,” says Professor Bell.