HIV/AIDS: Structured Interruption Boosts Immune Response

      Representing what some see as the "next conceptual push" in AIDS research, a small study conducted by researchers at Massachusetts General Hospital's AIDS Research Center found that some AIDS patients were able to control the amount of HIV in their blood by periodically stopping highly active antiretroviral drug therapy, the Boston Globe reports. Researchers hope that using "structured interrupted therapy" will provide information on how to keep HIV-positive patients' viral load levels in control, and eventually free patients from the burden of taking a large number of pills daily to fight the virus. By periodically stopping drug treatment, researchers found that although patients' viral load rebounded, there were signs that they were able to fight the reemerging virus with increasing success. They attributed the success to a strong "booster" effect of T-cells, which help the body fight HIV.

Tried & Tested
      Although they tested the technique in seven patients, Drs. Eric Rosenberg and Bruce Walker presented the findings of two specific patients at a Philadelphia conference last weekend. The first patient, a 32-year-old man with an undetectable viral load, stopped his therapy last July. After three weeks, his viral load rebounded to 17,000 viral copies per milliliter of blood and the doctors placed him back on therapy. He stopped again in January, and his viral load rebounded to 38,000 copies/ml and then steadily dropped to 400 copies/ml, without any therapy. They started and stopped therapy once more and found that his body kept the virus at low levels for nearly four months. The second patient started therapy with a viral load of 1 million copies and with drug therapy, his viral load fell below detectable levels. His treatment was halted last January and in three weeks, his viral load spiked to 100,000 copies/ml. When he stopped taking his therapy the second time, the virus remained undetectable for two weeks, then climbed to 200 copies/ml. For four months, his viral load fluctuated but never rose past 6,500 copies/ml. He is currently back on therapy and planning to stop soon for his next "booster shot" (Knox, Boston Globe, 11/22). Rosenberg said, "We theorize that T-helper cell responses may be significantly augmented with structured treatment interruptions in persons who are caught very early after infection and treated with potent therapy" (Morgan, San Jose Mercury News, 11/21). National Institutes of Allergies and Infectious Diseases Director Dr. Anthony Fauci said, "structured interrupted therapy is what everybody's excited about and working on." However, he cautioned that there could be no "definitive statements" until more patients are tested (Boston Globe, 11/22).