AIDSWEEKLY Plus, Monday, 10 February 1997
Daniel J. DeNoon, Senior Editor
Even when HIV RNA vanishes from the lymph nodes after aggressive treatment, proviral DNA persists.
Precisely how long the latent virus lurks is the question at the heart of whether HIV infection can ever be cured. Even though potent new treatments apparently eliminate HIV from the blood, the virus hides in the lymph nodes (and perhaps in other tissues) of infected individuals.
University of Minnesota researcher W. Cavert and colleagues used computerized quantitative image analysis coupled with in-situ hybridization (ISH) to detect evidence of HIV-1 in tonsil biopsies from ten patients with HIV infection.
They reported their findings in a session at the Fourth Conference on Retroviruses and Opportunistic Infections, held January 22-26 in Washington, D.C.
The patients, whose median CD4 count was 194 cells/(micro)L, received triple combination therapy with the protease inhibitor ritonavir (Merck) and the nucleoside-analog reverse-transcriptase inhibitors (NARTIs) zidovudine (AZT, Glaxo) and lamivudine (3TC, Glaxo). None of the participants had taken antiretroviral drugs previously.
Prior to treatment, the subjects' mean HIV RNA load in their follicular dendritic cells (FDC) - considered an important HIV reservoir - was 1.5x10(8) copies/gm. Their mean baseline frequency of actively productive (>=20 RNA copies/cell) mononuclear cells (MNCs) was 2.3x10(5) cells/gm of lymphoid tissue.
"We observed an initial quicker-than-expected turnover in the FDC-associated pool along with a rapid initial decrease in the MNC frequency," Cavert et al. wrote in their presentation abstract.
Six months' treatment reduced the mean FDC-associated virus pool by at least 3.8 log[10] and the MNC frequency by at least 2.2 log[10].
Most patients still had some residual HIV RNA after 180 days of therapy - except for one patient who, despite an "exhaustive" search with both quantitative ISH and a sensitive nested polymerase chain reaction (PCR) assay, had no detectable HIV RNA.
Nevertheless, this patient's lymphoid tissue carried detectable residual proviral DNA - what AIDS researcher David Ho has called the 'burning ember capable of re-igniting HIV infection'.
"Between individuals, the viral RNA residue varies as to the dominant cellular reservoir," Cavert et al. concluded. "In one subject lymphoid tissue RNA was undetectable, but proviral DNA persisted in all." - by Daniel J. DeNoon, Senior Editor
970210
AW970208
Copyright © 1997 - Charles Henderson, Publisher. All rights Reserved. Permission to reproduce granted to AEGIS by Charles W. Henderson. Authorization to reproduce for personal use granted granted by C. W. Henderson, Publisher, provided that the fee of US$4.50 per copy, per page is paid directly to the Copyright Clearance Center, 27 Congress Street, Salem, Massachusetts 01970, USA.
Published by Charles Henderson, Publisher. Editorial & Publishing Office: P.O. Box 5528, Atlanta, GA 30307-0528 / Telephone: (800) 633-4931; Subscription Office: P.O. Box 830409, Birmingham, AL 35283-0409 / FAX: (205) 995-1588 http://www.newsfile.com
AEGiS is made possible through unrestricted grants from Boehringer Ingelheim, iMetrikus, Inc., the National Library of Medicine, and donations from users like you. Always watch for outdated information. This article first appeared in 1997. This material is designed to support, not replace, the relationship that exists between you and your doctor.
AEGiS presents published material, reprinted with permission and neither endorses nor opposes any material. All information contained on this website, including information relating to health conditions, products, and treatments, is for informational purposes only. It is often presented in summary or aggregate form. It is not meant to be a substitute for the advice provided by your own physician or other medical professionals. Always discuss treatment options with a doctor who specializes in treating HIV.
Copyright ©1990, 2000. AEGiS. All materials appearing on AEGiS are protected by copyright as a collective work or compilation under U.S. copyright and other laws and are the property of AEGiS, or the party credited as the provider of the content.