Wistar Institute researchers float new HIV-monitoring strategy

    Global AIDS experts say “in these economic times” they’re looking for ways to get more HIV positive people into treatment using the money and resources they already have.

    Local researchers who say they’ve developed an innovative testing approach that might help.


    CD4 cells are white blood cells that fight infection, and CD4 tests are one way doctors figure out if a patient is responding to HIV therapy.

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    The hope is to see CD4 counts rebound to healthy levels, but routine CD4 testing helps drive up the cost of HIV treatment.

    In developing countries, especially, constant monitoring depletes limited resources, says Researcher Luis Montaner.

    “You need to buy this special reagent, you need to buy the machine with the laser,” Montaner said. “You need to have the capacity to run hundreds of these tests a day, and you have to have the people that know how to run the machines, take that data, analyze it and report it.

    “So, our object was to see whether we could come up with a strategy that could reduce the need of running CD4 tests on everybody that is on therapy, to try to identify an alternative indicator in recovery of CD4,” said Montaner, an immunologist with Philadelphia’s Wistar Institute.

    The Wistar team and colleagues developed a health-monitoring method that begins with a simple white blood cell count — with no high-end tools, equipment or training needed.

    “There are machines that actually count the specific type of cells that you have in your blood, you put the blood in and it counts it, and you get a report back out,” Montaner said.

    He says the approach could allow countries with limited resources to reserve more frequent CD4 tests for patients who aren’t responding well to treatment and need vigorous monitoring.

    Montaner’s team tested the health-monitoring strategy by scouring the patient data of about 1,900 people from seven sites around the world. It was a “look-back,” or retrospective, study.

    To confirm the findings, Montaner says, the next step is to field a prospective “forward-looking” study to monitor patients when they first start anti-retroviral therapy.

    In about 92 percent of the cases, the tool accurately predicted whether a patient got healthier – or not — after beginning HIV drug treatment. That level of accuracy translates to a 54 percent “hypothetical” reduction in the need for of CD4 tests, Montaner said.

    It’s a significant reduction, he says, that could free up HIV therapy resources.

    “Obviously, to actually treat more people, you need more money for drugs, for doctors, for nurses, for taking care of pharmacy demands,” Montaner said. “In itself, this tool is not going to result in more people being treated, because that requires a lot more other components to be in place. It just contributes one component that helps toward that goal.”

    In 2010, about 6.6 million people of low and middle income were receiving HIV treatment, according to the World Health Organization. That year, about 9 million more people were eligible for antiretroviral therapy but were not receiving it.

    Disclosure note: The Wistar Institute underwrites WHYY programming.

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