During the past year, scientists have shown that HIV persists in a latent form within a relatively small number of resting CD4+ T cells, even in patients who have received prolonged combination antiretroviral therapy and have no readily detectable virus in their blood. Latently infected CD4+ T cells are potential sources of new viral replication if a patient stops therapy, and pose a formidable obstacle to the goal of eradicating HIV from a person's body, particularly if drug resistance develops.
New data show that latent pools of infected cells are established very early in the course of HIV infection, even if a patient is treated expeditiously with highly active antiretroviral therapy ("HAART" - generally a three- or four-drug combination that includes a protease inhibitor). Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases (NIAID) and chief of the NIAID Laboratory of Immunoregulation (LIR), will present these and other new findings at the 12th World AIDS Conference in Geneva, Switzerland.
"We have shown that initiating HAART as soon as 10 days after the onset of the symptoms of acute HIV infection does not prevent the formation of a latent reservoir of virus," says Dr. Fauci. "By the time high levels of HIV are detectable in the blood, the virus probably has spread to the lymphoid organs and established a pool of latently infected cells.
"Our group and others are pursuing studies to identify and treat people recently exposed to HIV, before the burst of virus replication, which occurs in most patients soon after infection. Such studies will help determine whether it will be possible to prevent the early establishment of latent pools of HIV."
In Geneva, Dr. Fauci also will discuss the potential for diminishing latent
pools of HIV - the possibility of "flushing out" the virus (at least in the test
tube) - by stimulating latently infected CD4+ T cells with antibodies to the CD3
molecule on the cell
Contact: Greg Folkers
NIH/National Institute of Allergy and Infectious Diseases