When to start HAART in HIV

Well ,there has been no definite answers to this. CD4 count has been used to make the cut off. According to WHO,start if CD 4 count <350,>CASCADE (http://www.ctu.mrc.ac.uk/cascade/) group of investigators,on patients from their database tried to find an answer to this. Participants of the study were HAART-naive, AIDS-free, HIV-infected individuals between 1996 to 2009.Subjects were stratified by CD4 cell count. Those with cell counts above 800 cells/μL were excluded from the study.

The results of the study were presented in the AIDS 2010: XVIII International AIDS Conference in Vienna. Of 9455 patients with 52,268 person-years of follow-up, 812 (8.6%) developed AIDS and 544 (5.8%) died. Patients were followed up for roughly 5 years.

For those with CD4 0 to 49 cells/μL who started treatment,there was a 70% risk reduction,compared to those who were deferred treatment.

In those with CD4 cell counts between 200 and 349 cells/μL, there was 40% reduction in risk for disease progression or death.

for those with counts 350 to 499 cells/μL there was a 25% risk reduction in progression to AIDS/mortality.

There was no difference in risk of progression to AIDS in the 500- 799 cells/μL group.

Although this study did not include non HIV related deaths (eg.heart ,renal disease), it gives us a good evidence to start HAART at a CD4 count of <500>μL . The current WHO threshold of 350 cells/μL may be a little late in the progression of the disease to start HAART.