Facts and Issues [International Conference on AIDS (11th: 1996: Vancouver, Canada)]

Current Treatment Issues
Experimental treatments and new drugs are of intense interest to people living with AIDS
c and the general public.These issues, contained mostly within Track B: Clinical Science, also use
Q a great deal of technical language and refer to ever-changing drug names and categories. For
0 this reason, we have assembled the following information to offer journalists an overview of
0 the issues and themes we anticipate will be discussed at the XI International Conference on
AIDS. This section is by no means exhaustive or intended to give prominence to any one
drug. Rather, we hope it will serve as a primer (or a refresher) for working journalists
u reporting on HIV and AIDS.
The section begins with an overview of the many categories of anti-HIV therapies undergoing
experimentation.This is followed by information on treatments for the many opportunistic
infections (Ols) to which people living with AIDS are susceptible. Finally we conclude the
chapter with an overview of several concepts that are fundamental to understanding the
results of clinical experimentation.
Using Drugs to Modify the Effects of HIV
There are a number of approaches to drug therapy for HIV infection, focusing on different
stages of the viral life cycle and different aspects of the biology of the disease.
When the virus enters the body it infects (invades) the CD4T lymphocytes (also called CD4
cell orT4 cells orT-helper cells; cells of the immune system), and takes over their cellular
processes to make new viruses.These new viruses move from the infected cell to uninfected
cells to repeat their replication (reproduction) process.This production of new viruses is a
rapid and continuing process which recent research has confirmed begins from the very early
days of infection. Infection leads to death of the CD4 cell. However, rapid replacement of the
CD4 cells is able to overcome this destruction for a period of years.This is the time that a
person living with HIV remains healthy Eventually the continual barrage of HIV overwhelms
the ability of CD4 cells to regenerate, viral load (indicated by HIV RNA concentrations)
increases and AIDS develops (the person begins to get opportunistic infections). Given this
mechanism of disease development, therapies which lower viral load (or viral burden) and
elevate CD4 cell counts (reinforcing the immune system) are currently believed to be the
most useful approaches to delaying the appearance of AIDS.
Lowering Viral Load
It is believed that antiretroviral therapies can interfere with the infection and replication
process, thereby keeping viral load (amount of virus in the body) low, by:
* blocking HIV attachment to the CD4 cell
* blocking antigens on the virus envelope
* interfering with the uncoating of the virus as it enters the cell
* disrupting the translation of virus RNA to cell DNA
* disrupting the assembly and maturation of virus particles in the CD4 cell, and their release
as a free-floating virus in the body
Enzymes, such as reverse transcriptase and protease, are part of the production process.
Reverse transcriptase aids the translation of virus RNA to cell DNA during the early stages
of viral replication; protease is involved in assembling functional parts of the HIV during the
later stages of viral production. If these enzymes are prevented from doing their job, the
production of infectious viruses ceases.