A further signal that US clinicians are being steered away from early treatment
of HIV infection came today with the publication of an editorial in the Journal
of the American Medical Association suggesting that recent data appear to
support postponing treatment until the CD4 T lymphocyte count approaches 200
cells.
The
editorial implicitly endorses revised British treatment guidelines published in
July 2001, which recommended that antiretroviral treatment should be delayed
until the CD4 cell count had fallen close to 200 cells, unless the CD4 cell
count was falling rapidly.
British HIV Association guidelines, and the JAMA editorial, were developed
in response to recent data showing no additional benefit to starting treatment
with a CD4 cell count above 350 (the previous UK threshold for starting
treatment). This threshold is still recommended in the United States as the
time to begin antiretroviral therapy.
However,
two studies published today in JAMA show that:
- There
is no difference in rates of disease progression between people with CD4 cell
counts between 200-350, and above 350.
- There
is no difference in response to therapy (defined as probability of viral
suppression below 500 copies) between people who start therapy with CD4 cell
counts between 200 and 349 cells, and people with CD4 cell counts of 350 or
above.
These
studies are discussed in more detail in When to start treatment on tbis
website.
These
studies do not answer the question of when is the optimum time to start
treatment.
An
editorial in the November issue of AIDS Treatment Update, NAM’s
treatment newsletter, questions whether it is ethical to delay any longer the
development of a large randomized study that can answer the “when to start
treatment” question.
"In
the middle of the 1990s…plans for a large, international trial called Tempo
were drawn up. Tempo, which would compare immediate versus deferred
combination therapy, never got off the ground. There’s been no further plan for
this kind of when-to-start strategy trial since, in part due to practical
barriers such as the likely low clinical event rate, but also because the view –
not least from HIV treatment advocates – that such a trial would be unethical,
has been voiced so loudly. In comparison, few have questioned the ethics of not
doing a trial of this kind.”