Developments to Watch
THE LACK OF SYMPTOMS DOESN'T REFLECT AIDS' EARLY STRENGTH
One of the great puzzles of AIDS is why the disease usually takes years to develop. During the long period between initial exposure to the HIV virus and the first symptoms, scientists have detected only small amounts of the virus in the blood. This suggested that the infection exists at a low, latent level before it flares up.
But two new studies reported in the Mar. 25 issue of Nature overturn this theory. Researchers at the University of Minnesota-Twin Cities, the National Institutes of Health, and other institutions have found massive amounts of the virus present during the early, symptomless stage of the disease. Up to 25% of the cells in the lymph nodes are infected with the virus, reports the team led by Minnesota's Ashley T. Haase.
The results raise questions about current treatment. If so many immune-system cells are infected, drugs that are typically given later may not control the disease. The findings suggest that drugs should be started as soon as the infection is discovered. That "might reduce the amount of virus later," says oncologist Howard M. Temin of the University of Wisconsin, who co-authored an analysis of the studies in Nature. EDITED BY EMILY T. SMITH