No evidence of clinical benefit for patients starting
treatment with a healthy immune system
A paper published by the CASCADE
Collaboration in EuroCoord has found no evidence of clinical
benefit for patients starting HIV treatment at higher CD4 cell
counts of between 500-799
cells/mm3.
The introduction of highly active
antiretroviral therapy (HAART) in 1996 greatly improved the
survival rates of HIV positive people. Although the benefits of
treatment are evident, a central unresolved issue is when treatment
should be initiated.
HIV positive people are advised to start
treatment when important cells in their immune system, called CD4
cells, fall below a certain threshold.
Current guidelines in the United States
recommend that patients start treatment when their CD4 count is
between 350 to 500 CD4 cells/mm3 while the threshold for
treatment initiation in Europe generally remains at 350 CD4
cells/mm3.
This analysis included a total of 9,455
eligible patients from CASCADE who had not yet started treatment,
had not developed AIDS, and had CD4 counts of less than 800
cells/mm3.
The authors used a novel technique where a
series of sequential subcohorts of patients were created. Each
month between January 1996 and May 2009 was considered the starting
point for a subcohort, with patients who initiated treatment at a
number of CD4 strata during the month being compared with those who
did not. The results from the resulting 161 subcohorts were then
pooled and analysed.
The results confirmed the clinical benefit of
starting treatment with CD4 cell counts of between 200-349
cells/mm3, with an estimate of a 25% reduction in the
risk of AIDS or death.
Although the authors also found a benefit for
patients initiating treatment at CD4 cell counts of 350-499
cells/mm3, this was only evident beyond 2 years. There
was no clinical benefit for patients beginning treatment at higher
CD4 cell counts of between 500-799 cells/mm3.
Therefore, the authors suggest that “patients
need to consider the long-term course of treatment, including the
risk of adverse effects of HAART during an extended
period.”
Writing Committee for the CASCADE
Collaboration. Timing of HAART initiation and clinical outcomes in
HIV-1 seroconverters. Arch Intern Med 2011;171:1560-9.
[PubMed]
Find out more about the
CASCADE Collaboration