"First, these patients are not cured. When these patients went off therapy, HIV virus levels rebounded. These results do show that with effective early treatment that reduces the virus to very low levels, the immune system may have less antibody response to HIV," said the study's lead author, C. Bradley Hare, MD, UCSF assistant clinical professor of medicine at UCSF's Positive Health Program (PHP) at San Francisco General Hospital Medical Center.
The 87 patients who qualified for the study must have started antiretroviral therapy within 28 days of entry into the study. They also must have achieved and maintained for at least 24 weeks a level of virus in their blood below the level of detectability using very sensitive viral load testing. At some point during their follow-up, six patients tested negative for the HIV virus using standard HIV antibody tests.
Hare presented the study at the XV International AIDS Conference in Bangkok, Thailand on July 12.
Study participants were selected from the Options Project Cohort. Patients in this cohort enter the study in either primary or early infection -- meaning no patient had been infected with the HIV virus for more than six months.
The six patients who tested negative for the HIV virus were tested using standard second- and third-generation Enzyme Immunoassays, which are the most commonly used tests to screen for HIV infection, and Western Blot tests, which are the most commonly used tests for confirming HIV infection.
Co-authors for the study are Brandee Pappalardo, PhD, MPH, staff scientist at the Blood Systems Research Institute, San Francisco; Bruce Phelps, Chiron Corporation, Emeryville, CA; Steven S. Alexander, Ortho Clinical Diagnostics, Raritan, NJ; Clarissa Ramstead, nurse practitioner at the UCSF PHP; Jay A. Levy, UCSF professor of medicine and director of the Laboratory for Tumor and AIDS Virus Research; Frederick M. Hecht, MD, associate clinical professor of medicine at the UCSF PHP; Michael P. Busch, MD, PhD, vice president, Research & Scientific Services, Blood Centers of the Pacific, and UCSF adjunct professor of laboratory medicine.
Funding for this research was provided by grants from the National Institutes of Health and the Centers for Disease Control.
The Positive Health Program is a component of the UCSF AIDS Research Institute (ARI). UCSF ARI houses hundreds of scientists and dozens of programs throughout UCSF and affiliated labs and institutions, making ARI one of the largest AIDS research entities in the world.