Image depicting HIV virus

HIV drug improves white matter integrity in brain

An antiretroviral treatment has had unexpected benefits for HIV+ patients, according to new research by NeuRA scientist Dr Lucette Cysique.

Dr Cysique’s studies concentrate on the causes of HIV-related brain injury in people who have been successfully treated with antiretroviral drugs and have reached at least 45 years of age.

As part of the study, participants underwent a MRI scan using a method called Diffusion Tensor Imaging (DTI). This method is designed to measure the brain’s white matter integrity. The white matter of the brain is composed of bundles of myelinated axons, which connects brain regions. The human immunodeficiency virus is known to alter white matter via inflammation, which then disrupts the connections between brain regions, especially between the deeper part of the brain and the frontal lobes. Ageing brain processes can also disrupt the same circuits. Therefore it is possible that aging HIV+ persons may be at greater risks of white matter abnormalities.

A recent study by the group, however, revealed a more complex picture. In the sample that were successfully treated, the group detected evidence of brain repair marked by better white matter integrity as a function of historical immune recovery. In other words, the HIV+ persons who had the greatest recovery in their immune functions once they started antiretroviral treatment also had the strongest level of white matter integrity. This effect probably erased any combined disease and age effect so much that there was no major white matter integrity difference between the HIV+ and age-comparable HIV-negative controls.

The group found that disease duration and cardio-vascular diseases, rather than age, were associated with lower level of white matter integrity. It will be important to follow-up this cohort as they reached their 60s and 70s.