May 19, 2002
Twenty years ago, when Russell Van Dyke was beginning his career as a pediatrician, HIV and AIDS had just been identified. There was little in the way of effective treatment, AIDS in children was often fatal within months, and an infected pregnant woman had a 25 percent chance of transmitting the disease to her child.
Today, everything has changed. There is reason to hope that young people with HIV will live a normal life span. "HIV has become a chronic disease," said Van Dyke, who is the principal investigator of the Tulane/Louisiana State University Pediatric AIDS Trials Unit.
"It has become an endemic, treatable but not curable, sexually transmitted disease." The transmission rate from pregnant mother to child is down to less than 2 percent, a victory for which Van Dyke's team can take some of the credit.
Over the past 10 years, it helped develop the drug treatments that have led to healthier mothers and babies.
"We hardly ever see infected babies anymore," said Van Dyke. Tulane/LSU is one of 18 sites that make up the Pediatric AIDS Clinical Trials Group, which is funded by the National Institute of Allergy and Infectious Diseases. Funding for the group was renewed this year, but along with the funding comes a shift in focus. The new research agenda calls for greater emphasis on adolescents and on international research.
"We're looking at the problems in dealing with a chronic disease rather than an acute disease," Van Dyke said. "What are the long-term consequences for kids who are getting lifelong therapy with three or four drugs? We're just starting to see a glimmer of what they are."
Protease inhibitors, for example, can cause metabolic problems and high cholesterol levels. Some of the drugs may have long-term effects on muscles, nerves and the central nervous system. The other problem is adherence. Treatment involves taking a large volume of drugs every day. It can be hard to stay motivated or to remember to take them.
Maggie Silio, assistant professor of pediatrics, is designing a study for the group that will look at behavioral interventions that might help motivate adolescents to stick with their treatment. The study will have a component looking at the results of therapeutic drug monitoring, to see if by monitoring drug levels in the patient and adjusting the doses the patient does better.
The study will also have a component that compares two drug regimens to see which works better for adolescents. Their work with adolescents is also helping set the stage for preventive vaccine trials. In order to do such a trial, the need is to identify a population that isn't infected but is at high risk. That population could be adolescents of a similar demographic as those currently being followed by the group.
"In order to design a study you've got to identify a high-risk but uninfected population and show you've got access to them," Van Dyke said. He estimates a large vaccine study could get under way in three or four years.
Internationally, researchers want to see if they can begin to bring the epidemic under control by reducing the mother-to-child transmission rate, adapting techniques that have been useful in the United States. New Orleans is one of five sites in the country that is currently testing a rapid HIV test for women who enter the hospital in labor without knowing their HIV status. The results of the test are known in 15 minutes, and if the woman is infected she and her baby receive medicine that reduces the likelihood of transmission.
But in Africa and other places where the epidemic is still quite severe, such techniques could have a revolutionary effect. The Pediatric AIDS Clinical Trials Group has opened units in South Africa and Thailand in the last two years.
"We decided to do these studies in mid-developing countries like South Africa and Thailand because they have the resources to benefit from the results of the research," Van Dyke said. He believes there is hope that AIDS will be brought under control globally. "Things are changing very rapidly. As soon as people get past the psychological barrier of thinking that we can't do it, they discover that we can do it, and the resources become available."
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