- WASHINGTON (Reuters) - Cocaine
not only makes people act recklessly -- having unsafe sex that can lead
to HIV infection -- it can also give the virus a kick-start, scientists
reported on Thursday.
-
- Tests in mice show that cocaine helps the virus spread
faster in the body, killing off more immune cells and reproducing 200 times
faster than usual.
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- "Cocaine not only influences risky behaviors, it
also has a direct and profound effect on the AIDS virus," Dr. Gayle
Baldwin, an AIDS researcher at the University of California Los Angeles
who led the study, said in a statement.
-
- The spread of the virus and its effects on immune cells
known as CD4 T-cells are directly related to how sick a person becomes
with HIV infection.
-
- Baldwin knew that people who use drugs are more likely
to become infected with HIV and she knew this was also the case specifically
with cocaine, which is not usually injected -- the usual route of HIV infection
for drug users.
-
- "There were some studies done quite some time ago
that suggested a correlation between cocaine use and the progression of
disease in HIV-positive individuals," Baldwin said in a telephone
interview.
-
- She also knew that cocaine can affect the immune system.
-
- Writing in the online edition of the Journal of Infectious
Diseases, Baldwin said she and colleagues tested specially bred mice that
are infected with the human AIDS virus.
-
- Half the mice got daily injections of liquid cocaine
and half got salt water. They tested the mice 10 days later.
-
- "We saw a 200-fold increase in AIDS viral load in
the blood of the animals injected with cocaine compared to those that received
the placebo," Baldwin said. "In only two weeks, the drug radically
stimulated the production and spread of HIV."
-
- Viral load is a measure of how much virus is circulating
in the blood. Baldwin's team also looked to see how many CD4 cells had
been killed.
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- COCAINE WIPED OUT CD4 CELLS
-
- "The cocaine increased HIV's efficiency so dramatically
that it nearly wiped out the CD4 T-cells. We found nine times fewer CD4
T-cells in the cocaine-treated mice than in the animals that received the
placebo," Baldwin said.
-
- "This means that the cocaine produced a spectacular
double outcome," she added. "Not only did the drug double the
number of HIV-infected cells, it produced a nine-fold plunge in the number
of T-cells that fight off the virus."
-
- The cocaine could be working on many levels, Baldwin
said.
-
- It could be increasing the number of molecular doorways,
called receptors, that HIV uses to get into the cells it infects. Cocaine
may cause cells to sprout more CCR5 and CXCR4 receptors, both of which
are used by HIV, she said.
-
- It may also increase the levels of cytokines, chemical
messengers, such as TGF-beta and IL-10, which also affect HIV.
-
- A revved-up immune system only helps HIV, which is so
insidious and difficult to fight because it thrives on and destroys the
very cells sent to attack it.
-
- Baldwin said her work could be important, because recent
studies show that younger people are returning to risky sexual behavior,
such as not using condoms, because they are losing their fear of AIDS.
-
- "Cocaine is still a very bad problem in populations
at risk," she said.
-
- She said it is not clear whether taking cocaine might
make a person more likely to contract HIV from an infected sex partner
or a contaminated needle. Copyright © 2002 Reuters Limited. All rights
reserved. Republication or redistribution of Reuters content is expressly
prohibited without the prior written consent of Reuters. Reuters shall
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taken in reliance thereon.
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