Researchers from Canada have found that delaying HAART until your CD4 count falls below 200 may not seriously increase your risk of dying – provided you start treatment before your CD4 count falls below 50 cells/mm3
The researchers looked at all patients who commenced HAART in British Columbia since 1996, and found some startling results. Focussing solely on the risk of death after commencing HAART, they found little substantive difference in the impact of baseline viral load on survival. Instead, they found that the CD4 count when HAART began was a much stronger predictor of survival
Thus, people with viral load above 200,000 copies at the time they started therapy had less than twofold higher risk of death when compared to people with lower viral load within the same CD4 band (see table).
|
Baseline VL and CD4
|
VL below 50,000 copies |
VL 50,000- 200,000 |
VL above 200,000 copies |
|
CD4 above 200 cells/mm3 |
1.15% |
3.2% |
7.2% |
|
CD4 between 50 and 200 |
5.4% |
7.3% |
11.98% |
|
CD4 below 50 |
22.64% |
25.7% |
19.2% |
Percentage of individuals dead within two years of commencing HAART in British Columbia, August 1996 to January 2000, according to viral load and CD4 count at time of starting treatment
Later this week the same group is due to present further data that will show no significant difference in the risk of death between people who start HAART with CD4 counts between 350 and 500, and people with CD4 counts between 350 and 200.
These findings suggest that treatment guidelines that focus on relatively small differences in viral load (e.g. between viral load above and below 10,000 or 30,000 copies), and on the risk of disease progression without treatment, especially in patients with CD4 counts above 200, need to balance those risks with the subsequent reduction in risk of death when HAART is commenced.
Explaining why the British Columbia group conducted the analysis, Montaner said: "We have been focussing on John Mellor’s data too long, and the question that our patients have been asking all along is, how late can I start without compromising the effectiveness of HAART?"
"We need a resurgence of emphasis on the CD4 count as the determinant of when to start treatment" said Montaner, who was speaking during a debate on whether it is appropriate to use dual therapy in resource poor countries. Montaner argued that rather than compromising the aim of treatment – maximal suppression of viral load – treatment could be deferred until far later in the course of HIV disease.
However, a press conference earlier in the day found "hit hard, hit early" advocate Dr David Ho unrepentant in his recommendation that treatment should start as early as possible, in order to avoid "the terminal death of very important cells in the immune system".