Multidrug Therapy Arrests HIV Early On
Nov. 21, 1999 (Atlanta) -- Signs of early, or acute, HIV infection sometimes go unnoticed by doctors, but catching them early and then starting treatment with a potent multidrug therapy could slow or even prevent the disease from going forward.
That is the conclusion of a study presented today at the 37th annual meeting of the Infectious Diseases Society of America in Philadelphia. "If someone comes in with flu-like or mononucleosis-like signs or symptoms, a history should be obtained to elicit HIV risk factors," says Eric Rosenberg, MD, an infectious disease specialist at Massachusetts General Hospital in Boston. "If they do have HIV risk factors then it would be prudent to test them for acute infection."
The problem with testing at that early stage is that the standard measure of infection -- a check for antibodies against HIV -- is unreliable for about the first two months following infection. Rosenberg says doctors thus need to choose either a "viral load" test or one called the P24 antigen test.
Rosenberg and his fellow investigators came to their conclusions after studying the response of 25 people who were acutely infected with HIV and were put on the potent, multidrug therapy known as HAART, which stands for highly active antiretroviral therapy.
Using radioactive measurements, the researchers were able to determine each person's "immune response" at several points during the study. They found that at one year out, all but two of the patients fit into the category of "long-term non-progressors." In other words, they were still infected with HIV, but the virus wasn't making any headway in their bodies. And the two that didn't respond were found to have viruses that were resistant to the drugs being used.
Another important finding came out of the study. After a year of HIV containment, two of the subjects chose to stop taking the drugs. Within two to three weeks, the amount of virus in their bodies increased. Once they were put back on the HAART regimen their viral levels fell again, as expected -- but researchers also found the "drug break" resulted in an enhanced immune response. And the response only got stronger in some patients after subsequent interruptions in drug therapy -- with one subject registering a tenfold increase after two to three treatment interruptions.
"Clearly, it seems that the immune system can be boosted to improve control of HIV without therapy," Rosenberg says. "However we haven't figured out how much it's got to be boosted in order to completely control viral replication."
And Rosenberg strongly cautions that there may be hidden dangers with interrupting therapy -- including the development of drug resistance and an increase in the number of cells with dormant infections.