cocaine causes hiv to progress

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COCAINE AND INTENSITY OF H.I.V. ARE RELATED IN A STUDY OF MICE

By Grady

New York Times 15 Feb. 2002

Research in mice may help explain something that doctors have

noticed in people who are infected with H.I.V.: cocaine use seems to

make the disease progress faster and lead to more of the

opportunistic infections that are the hallmark of AIDS.

The reason is not known. Drug abusers often eat poorly, have

unprotected sex and neglect their health in other ways, so it has

been impossible to tell whether their problems are due to cocaine

itself or to the other habits that often go with addiction.

A new study suggests that cocaine is to blame. In the study, by

researchers at the AIDS Institute at the University of California at

Los Angeles, specially bred mice were inoculated with human cells

and with H.I.V., the virus that causes AIDS, and then given

injections of either cocaine or a salt-water placebo. Cocaine

greatly enhanced replication of the virus and increased the number

of human cells it infected and killed.

Dr. Gayle C. Baldwin, who directed the study, said, " We're talking

about a 200-fold increase in viral load in these animals. That is a

lot. "

In addition, Dr. Baldwin said, the mice given cocaine had only one-

ninth as many CD4 cells as the mice given salt water. CD4 cells,

also called helper T cells, help to activate other cells of the

immune system. They are the prime targets of the AIDS virus, and

when they are wiped out, the ability to fight off infections is lost.

The virus also infects other cells, and, Dr. Baldwin said, " We're

seeing that the population of cells that are not killed off are

churning out incredible amounts of virus. "

Why that occurs is not known, she said, adding, " We're working on

that right now. "

Dr. Baldwin said that cocaine had powerful effects on both the

nervous system and the immune system, and that it caused the body to

produce steroid hormones and other substances that might affect

H.I.V. and its ability to invade cells.

A report on the study will be published in the March issue of The

Journal of Infectious Diseases and is being posted today on the

Internet at www.journals.uchicago.edu/JID/journal.

Dr. Warner C. Greene, director of the Gladstone Institute of

Virology and Immunology at the University of California at San

Francisco, who was not involved in the study, said doctors had

wondered why cocaine users had a worse course with H.I.V.

" The beauty of this study, " Dr. Greene said, " is that it really

focuses in and reveals some specific effect of cocaine. One clearly

sees that cocaine is doing something to the infection process. "

Dr. Greene also said he thought the study would enhance both

doctors' and patients' awareness of cocaine's potential to

accelerate the course of H.I.V. infection.

" I think it has very significant implications for people infected

with H.I.V., " he said.

Dr. Baldwin said that even though the study was done in mice, she

thought the findings would apply to people.

" There's always controversy with animal models, " she said. " But

among people who do H.I.V. research, this is an accepted model. You

can't address these questions in a human population. It would be

unethical. This model offers us something nothing else really can. "

Dr. Greene said, " It's a model, but, boy, the effects they saw were

significant. "

The mice in the study were inoculated with human cells because mouse

cells do not become infected with H.I.V. The mice in the study

lacked immune systems, and so would not reject human cells. The mice

could then be injected with H.I.V.