Latest Drug 'Cocktails' Fail to Halt Growth of AIDS Virus in Blood
Nov. 2, 1999 (Seattle) -- Even the latest and most powerful drugs can't completely stop HIV, the virus that causes AIDS, according to a study in the Nov. 3 issue of the Journal of the American Medical Association (JAMA). However, experts say the drug cocktails do allow the body's immune system to regain much of its ability to ward off other infections and diseases that cause illness in AIDS patients.
Roger Pomerantz, MD, an author of the study, says that even when drugs appear to have reduced HIV to undetectable levels in the bloodstream, there are still a few viruses capable of reproducing. Pomerantz, who directs the Center for Human Virology at Jefferson Medical College in Philadelphia, says these lingering viruses are "the embers that reignite the viral brushfire" if treatment ever stops.
Pomerantz says previous studies found evidence that HIV remains in some body tissues despite treatment. But these studies found that blood from many HIV patients undergoing treatment appeared to be free of virus. So Pomerantz and his colleagues used a new and far more sensitive test to examine blood from 22 such people.
The researchers found that all of them had tiny amounts of virus in their blood, and that 10 also had virus in genital secretions. "When you look closely enough you find it in everybody," he says. "That was shocking to us."
Pomerantz says the finding confirms that people taking HIV drugs can never stop because the remaining virus would quickly multiply. He says the study also shows that doctors need to begin experimenting with even more potent drug combinations. Such combinations might eliminate the virus, or at least keep it from reproducing in the body, he says.
But Bruce Walker, MD, director of the AIDS Research Center at Massachusetts General Hospital in Boston, tells WebMD he's not convinced that more powerful drug regimens are a good idea. Walker, the co-author of an editorial on HIV treatment in the same issue of JAMA, says, "We don't know whether the benefits of adding more drugs would outweigh the risks.''
Walker says that even though the virus continues to replicate itself in spite of drug treatment, the rate is so slow that it may pose little threat to the immune system.
Just slowing down replication of the virus allows even badly damaged immune systems to recover, Scott Whitcup, MD, tells WebMD. Whitcup, the clinical director of the National Eye Institute at the National Institutes of health, reports in JAMA that a common eye infection seen in HIV patients often resolves after they begin treatment with the new drug combinations.
He says HIV patients whose eyes are infected with a virus called cytomegalovirus (CMV) often go blind even if they receive daily doses of intravenous drugs. But 14 patients with infected eyes were able to stop the intravenous treatment after they began taking the potent HIV drugs.
"It's quite encouraging," Whitcup says, "because it means that their immune systems have been restored enough to fight this infection, and probably many other infections."