Resource Logo
San Francisco Examiner

AIDSWEEK: Gene therapy a new frontier in HIV fight




 

THIS WEEK, Bay Area volunteers are participating in the first study of the safety and feasibility of genetically modified blood cells designed to fight HIV infection.

Patients receive an infusion of their own cells, which have been modified to include a mutant gene that interferes with the ability of HIV to reproduce. The experiment is being conducted by the AIDS Community Research Consortium in Redwood City.

"Gene therapy is a potentially exciting new approach to treating a number of diseases that have resisted treatment in the past, including HIV infection and various cancers," said Dr. Stan Deresinski, principal investigator of the study.

Jacqui Sheffield is a study participant. When she was diagnosed with HIV, she said to herself, "AIDS equals death. That's what I thought. I immediately thought about my beautiful son,and I began to imagine not being able to see him grow up. After months of feeling sorry for myself, I decided to take action."

Now she is taking combination therapies and volunteering in the gene therapy study. Her participation will help scientists understand the process of "harvesting" blood cells called stem cells, which are the primary generators of immune cells that fight disease. The consortium trial is the first to test the potential of stem cell-based gene therapy.

"I wanted to take part in some of the newer approaches to treat HIV infection, so that some day all patients may be helped," Sheffield said. Chemokine protection

Fourteen hemophiliacs who were repeatedly exposed to HIV resisted infection because they had high levels of immune system proteins called chemokines, a study suggests.

The study involved 128 hemophiliacs who had repeatedly been exposed to HIV from blood products from 1980 to 1985. Only three were infected by the first infusions. The total number of those infected rose to 59 in 1982, 84 in 1983, 103 in 1984 and 114 in 1985.

The pattern shows that most hemophiliacs had a natural - but temporary - resistance to HIV infection, The Associated Press reported.

Blood cells taken from them were found to produce about twice as much of three kinds of chemokines as did cells from healthy blood donors, or from hemophiliacs unexposed to HIV, according to the research, reported by Dr. Daniel Zagury, of the Pierre and Marie Curie University in Paris; Alessandro Gringeri, of the University of Milan in Italy; and Dr. Robert Gallo of the Institute of Human Virology at the University of Maryland in the latest issue of the Proceedings of the National Academy of Sciences.

Prior studies have shown that chemokines can block HIV infection in the test tube, and scientists have been hoping to use them to develop AIDS drugs or a vaccine.

Monkey viruses

U.S. researchers reported this week that they have evidence that people can be infected with monkey viruses - including one laboratory worker who got infected with SIV, the monkey equivalent of the HIV virus that causes AIDS in humans.

The findings have implications for research into xenotransplants, animal-to-human organ transplants, said researcher Walid Heneine of the U.S. Centers for Disease Control and Prevention, who reported his findings in the journal Nature Medicine.

Heneine tested the blood of 231 lab workers who handled monkeys and found that five had become infected with monkey viruses. One had SIV, and four were infected with a simian foamy virus, common in laboratory monkeys.

The viruses were not harmful in any of these people, he said.

But researchers fear that people given an organ of an animal might catch an animal virus that turns dangerous.

"The impact on xenotransplants is that, yes, we have documentation that people who receive xenotransplants from SIV-infected baboons may very likely get infected with SIV virus, but we don't have any evidence that it will harm them," Heneine told Reuters.

The viruses came from an African green monkey and from baboons. All the infected lab workers reported suffering injuries, such as bites from the monkeys.

But the workers did not get sick. Nor did their spouses. Tests of old blood donated by the workers found that one was infected for at least 20 years and another for nine years.

Robin Weiss, an expert in viruses at the Institute of Cancer Research in London, said viruses have been hopping from animals to humans for generations, but rarely cause an epidemic. HIV, thought to have mutated from SIV, is a major exception.

But he added in a commentary in Nature Medicine that "we understand all too little about what allows viruses to adopt and spread in a new host."

New test

The government is recommending use of a new HIV test that yields results instantly instead of a week later.

The CDC says the rapid test will address a major drawback of the current method: Nearly 700,000 people a year never return to find out their test results. And because they are tested anonymously, there is no way for clinics to call and inform them of their infection.

The new test means that more people will be able to get prompt education and treatment.

"Most people either don't want to or are afraid to deal with it unless they become sick," said Tony Braswell, executive director of AIDS Atlanta. "If you can tell someone while they are sitting there, talking with a counselor, you could get a head start with them . . . and tell them that their life is not over."

The test, manufactured by Murex of Norcross, takes about 10 minutes to determine whether the virus is present. Both the new and the old tests look for antibodies in the blood. However, the traditional, one-week test also looks for specific protein bands, which are considered the absolute indicator of HIV.

About 8,000 people annually would initially receive false-positive results from the new test, said Bernard Branson of the CDC. In contrast, the current one-week test is nearly 100 percent accurate.

To combat false results, clinics give three quick HIV tests. If one or more comes back with a positive reading, a traditional blood test is taken and the results are made available in about seven days.

The toll

Jon M. Gilreath, 46, a Phi Beta Kappa graduate of Michigan State University with an MBA from UC-Berkeley who then became an executive at California Public Radio and Pacific Bell . . . Douglas A. Smith, 50, a Massachusetts native who was director for the Social Security Administration for 24 years.

. . . . . .Date . . . . . .reported. . Cases. . Deaths S.F.. . . .3/1 . . . . 25,148. .17,049 Calif.. . .3/1 . . . .105,121 . 66,450 U.S.. . . .3/1 . . . .612,078 .379,258 WHO(rprtd) 3/1 . . .8,400,000 6,400,000

Figures are cumulative since June 1981. Government officials now compile and release statistics quarterly, not monthly. To contribute to AIDSweek, call (415) 777-7867.



 


Copyright © 1998 -The Bangkok Pos, Publisher. All rights reserved to San Francisco Examiner. All rights reserved. Reproduced with permission. Reproduction of this article (other than one copy for personal reference) must be cleared through the San Francisco Examiner, Permissions Desk, 110 Fifth Street, P.O. Box 7260, San Franciso, CA 94120.San Francisco Examiner

Information in this article was accurate in April 1, 1998. The state of the art may have changed since the publication date. This material is designed to support, not replace, the relationship that exists between you and your doctor. Always discuss treatment options with a doctor who specializes in treating HIV.