The New York Times - April 30, 2009
Roni Caryn Rabin

A new analysis suggests that sooner is better than later.

The study, which is not the final word on the matter, tracked the survival rates of 17,517 asymptomatic North American patients with H.I.V. who started drug therapy at different points, as determined by blood levels of the immune system's CD4 cells, which decline as the infection progresses.

The analysis found that asymptomatic patients who postponed antiretroviral treatment until their disease was more advanced faced a higher risk of dying than those who had initiated drug treatment earlier.

The paper, posted online this month, was to be published Thursday in The New England Journal of Medicine.

"This has been one of the most important questions in the last decade: what the optimal timing is for starting therapy," said Dr. Mari M. Kitahata, director of clinical epidemiology at the Center for AIDS and S.T.D. at the University of Washington in Seattle and the paper's first author. "Our study provides evidence that patients would live longer if antiretroviral treatment was begun when their CD4 count was above 500."

That could mean starting drug treatment several years earlier than is currently recommended, since national guidelines now advise starting antiretroviral therapy in asymptomatic patients when their CD4 counts dip below 350.

A separate report published online two weeks ago in the journal Lancet came to a similar conclusion.

The new study suggests, however, that even earlier treatment may be beneficial. The study analyzed two groups of H.I.V.-positive patients who received care from 1996 to 2005 in the United States and Canada, were asymptomatic and had never previously been on antiretroviral therapy.

The first group had 8,362 patients, 2,084 of whom started therapy when their CD4 counts were from 351 to 500 cells per cubic millimeter, and 6,278 with similar counts who postponed therapy until their counts fell to 350 or less. Among those who deferred therapy, the risk of dying was 69 percent higher, the researchers found.

In the second group, made up of 9,155 patients with CD4 counts of more than 500, 2,220 started therapy within six months, while 6,935 postponed therapy. Of those, 3,881 had counts that dropped, and 539 initiated antiretroviral therapy within six months of a count of 500 or less.

Among those who deferred therapy, the risk of dying was 94 percent higher than those who initiated therapy early on.

The new analysis is an observational study, not a clinical trial, and as such does not provide definitive answers, said Dr. Paul E. Sax, clinical director of the division of infectious diseases at Brigham and Women's Hospital in Boston, who wrote an editorial accompanying the paper.

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