People infected with HIV often have clinical conditions that are normally associated with people of older age. A study at UCLA found that HIV causes CD4+ helper T-cells to age rapidly. In the study of HIV positive people who were not on anti-retroviral medication (ARVs), HIV caused these cells to age 20-30 years over three years. In the CD4+ cells that are not killed by HIV, there is dramatic shortening of the telomeres which are important in protecting chromosomes. This discovery could be used to develop more effective treatments for HIV. The study also examined if HIV positive people on ARVs had the same aging effect on their CD4+ helper T-cells. In subjects who kept their viral load low by effective control of their HIV-1 infection with ARVs, there were still effects of advanced aging but not as dramatic as those not on ARVs.