Based on evidence of increasing health problems among positive people with relatively high CD4s who are not yet on HIV meds, the U.S. treatment guidelines raised the recommended starting point of drug therapy from 200 to 350 CD4 cells a year ago. But researchers at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) last August suggested a higher starting point: 500.

A review of records of 8,374 positive people in the United States and Canada from 1996 to 2006 found that the risk of dying from any cause was 70 percent lower for people who started meds with CD4 counts between 351 and 500 than for those who started with counts between 200 and 350. These results, reported by researchers at the University of Washington in Seattle, echo other large HIV studies suggesting that HIV meds protect against health problems seemingly independent of HIV—such as heart disease and cancer.

It's not yet clear whether earlier treatment raises the risk of side effects or drug resistance. While current treatment guidelines still say to start at 350, a change could be coming.