Is HIV Growing Stronger?

HIV's trump card over humanity's quest to defeat the virus is its ability to change itself'to literally rearrange its genetic makeup to escape the medications and experimental vaccines aimed to suppress or destroy it. But a study presented at the 48th Interscience Conference on Antimicrobial Agents and Chemotherapy suggests that HIV may be changing in yet another'and an unexpectedly dangerous'way; it could be mutating to better evade the body's natural defenses and to more quickly wreak havoc on the immune system. Nancy Crum-Cianflone, Ph.D., and colleagues at the Tri-Service AIDS Clinical Consortium analyzed data from nearly 2,000 HIV-positive U.S. military personnel from 1985 to 2004. Because soldiers are regularly screened for HIV infection, the study subjects had a previously known HIV-negative date and had all recently seroconverted. The analysis was alarming. People who seroconverted between 2002 and 2004 had initial CD4 counts an average of 113 cells lower than those diagnosed between 1985 and 1990. And the percentage of HIVers diagnosed with CD4 counts below 350 cells climbed from 12% in 1985'1990 to 25% in 2002'2004. 'Why did we see such a difference?' Crum-Cianflone asks. 'There are three possible reasons. The first is a change in environmental influences, which we haven't seen. The second is a change in people, which would be surprising, since genetic changes in humans usually occur over many generations, not just several years. And the third is that the virus itself has changed and become more virulent. We're not sure yet which of these hypotheses is right, but we already know that HIV can change pretty readily.' If HIV has indeed enhanced its ability to devastate the immune system, it could affect treatment plans for HIVers, particularly those recently diagnosed, says Robert Grossberg, MD, medical director of the Center for Positive Living/Infectious Diseases Clinic at Montefiore Medical Center in the Bronx, N.Y. 'There's already increasing data to support starting medications at higher CD4-cell counts and maybe even good reason to start when counts are above 350,' he explains. 'HIV that is increasingly virulent might lead patients and providers to lean toward starting meds on the earlier side.' 'We're not trying to scare people and say they should be more fearful of HIV,' adds Crum-Cianflone of her team's findings. 'What we're saying is that it may be more important than ever for HIV-positive people to get regular follow-up care and closely monitor their CD4-cell counts. And it's important for everyone to get tested regularly so that if you are positive, you can get care and initiate treatment before there's significant immune system damage.'