NEW YORK (Reuters Health) – A South African study shows that HIV-infected patients do better when they begin treatment above rather than below 200 cells/µL.

The results, reported in a July 5 online issue of AIDS, support World Health Organization recommendations that HIV treatment be initiated when CD4 counts fall to 350 cells/µL, rather than to 200 cells/µL as had been the standard in developing countries.

“The recent changes in WHO guidelines have yet to be adopted globally” write Dr. Matthew P. Fox, of Boston University, Massachusetts, and colleagues in the US and South Africa. “In order to support decision-making around when to initiate ART, we assessed the association between treatment outcomes and starting ART at higher CD4 cell counts using data collected as part of (a) randomized trial comparing nurse-monitored antiretroviral treatment with doctor-monitored treatment in South Africa.”

Of the 812 patients with CD4 counts below 350 cells/µL followed for a median of over 2 years in the trial, 36% began antiretroviral therapy when their CD4 count was above 200 cells/µL. The virologic failure rate in this subset was 6.8%, compared with 12.2% in those initiating therapy at counts of 200 cells/µL or below.

The corresponding mortality rates in the two groups were 0.7% vs. 3.7%.

“After adjustment, those with a CD4 cell count of 200 cells/µL had twice the risk of death/virologic failure (hazard ratio 1.9) and twice the risk of incident tuberculosis (hazard ratio 1.90) as those above 200 cells/µL,” the team reports.

“The main take-home message is that treating patients earlier leads to better outcomes over the first few years of treatment, particularly in terms of reduced mortality, even though this was a rare outcome,” Dr. Fox summed up in an emailed comment.

He and his colleagues point out that the findings are consistent with data from resource-rich settings, and join an emerging body of evidence showing the benefits of earlier treatment initiation in resource-limited settings.

That said, the authors sound a caution in their paper: “If thresholds are increased, then substantial efforts will need to be made to move patients into care earlier in their disease progression in order to obtain the maximum benefit from ART.”

The important issue is cost, Dr. Fox concluded. “It is not clear at this point what the cost would be to increase the CD4 threshold for initiation, but there would likely be some. But what has not been thoroughly studied yet is what the cost savings would be from increasing the CD4 threshold. Since a substantial portion of the cost related to HIV treatment comes from hospitalization, treating patients earlier, before they get very sick, has the potential to reduce costs through reducing hospitalizations.”

Reference:

Initiating patients on antiretroviral therapy at CD4 cell counts above 200 cells/[mu]l is associated with improved treatment outcomes in South Africa

AIDS 2010;24.