FOR IMMEDIATE RELEASE ON March 24, 2006
Antibiotic May Help Fight Dementia in HIV Patients
EMBARGOED FOR RELEASE UNTIL 7:30 A.M. PT, WEDNESDAY, APRIL 5, 2006
San Diego -
An antibiotic may help prevent dementia in HIV patients, according to a study that will be presented at the American Academy of Neurology 58th Annual Meeting in San Diego, Calif., April 1 – 8, 2006. “People infected with HIV often develop dementia as part of their illness, but there is currently no specific treatment for this complication,” said the study’s lead author, Jeffrey Rumbaugh, MD, PhD, of Johns Hopkins University. According to the researchers, two HIV proteins, called Tat and gp120, have been implicated in the development of HIV dementia. One effect of these proteins is to reduce expression of a neuronal membrane receptor, called EAAT-2 (excitatory amino acid transporter-2). EAAT-2 absorbs the neurotransmitter glutamate from the space between neurons (the synapse), thereby preventing excess neuronal excitation which can cause cell death. Researchers believe that by reducing EAAT-2, the HIV proteins increase brain damage, which leads to dementia in patients. The antibiotic ceftriaxone is a known stimulator of EAAT-2 expression, and protects against neuronal injury in mice in other disease states, including motor neuron disease. To test ceftriaxone's potential in HIV, Rumbaugh and colleagues created human neuronal cell cultures, treated them with a range of doses of ceftriaxone, then exposed them to Tat or gp120. They found that the antibiotic protected the neurons against both HIV proteins. The dose of ceftriaxone needed for protection was well within the range currently used for treatment of bacterial infections. “Further trials will be needed before it can be used in the clinic,” said Rumbaugh, “but these results indicate that this class of drugs may prove effective in treating HIV patients with dementia.” This study was supported by grants from the National Institutes of Health.