HIV-positive patients in South Africa can
have a near-normal life expectancy, provided that they start antiretroviral
therapy promptly, investigators report in the open access journal PLoS Medicine. Individuals who started
therapy when their CD4 cell count was above 200 cells/mm3 had a life
expectancy of approximately 80% of that of matched HIV-negative individuals.
“These results are encouraging,” comment
the authors. Even better life expectancy was associated with starting treatment
after 2006 and longer duration of therapy. The investigators believe that the
revision of South African treatment guidelines recommending the initiation of
therapy at CD4 cell counts of 350 cells/mm3 and testing campaigns
are likely to lead to further improvements in prognosis.
The investigators undertook their research
because little is known about the life expectancy of patients taking anti-HIV
drugs in low- and middle-income countries. Several studies have shown that the
prognosis of many HIV-positive patients in richer countries is now normal or
near normal. But it is open to question if similar gains have been achieved in
less well resourced settings which often face significant challenges in the
delivery of healthcare and HIV treatment. In particular, very late HIV diagnosis might be expected to moderate improvements in life expectancy.
A team of investigators therefore examined
data obtained from six South African antiretroviral therapy cohorts. A total of
37,740 patients starting HIV therapy between 2001 and 2010 were included in the
authors’ analysis. The large sample size and the diverse populations
represented in these cohorts were major strengths of the study.
Mortality was estimated by linking patient
records to the South African national population register. The excess mortality
attributable to HIV was then estimated. The investigators took into account
factors such as age, CD4 cell count at the initiation of HIV therapy and the
duration of treatment.
Most of the patients were female (62%) and
three-quarters were aged between 25 and 44 years. For most of the period of
analysis, patients only became eligible for treatment when their CD4 cell count
dropped below 200 cells/mm3. Therefore, 87% of patients had a
baseline CD4 cell count below this threshold and only symptomatic patients with
higher CD4 cell counts were eligible for therapy.
There were 5,782 deaths during 69,514 person-years
of follow-up. The overall mortality rate was 83 per 1,000 person-years. It was
substantially higher for men (100 per 1,000 person years) than women (73 per
1,000 person years). Mortality rates were highest during the first twelve
months of HIV treatment and then fell to low levels with longer duration of
HIV-negative men and women aged 20 had an
average life expectancy of a further 45 and 53 years respectively.
Overall, HIV-positive men and women aged 20
at the time they started antiretroviral drugs had average life expectancies of
a further 28 and 37 years.
Life expectancy increased with baseline CD4
cell count. Overall, the life expectancy of patients with a count above 200
cells/mm3 when they started treatment was between 70% and 86% of
those of their HIV-negative peers. However, patients whose CD4 cell count was
below 50 cells/mm3 had a life expectancy of between 48% and 61% of
those in HIV-negative individuals.
“South African patients starting ART have
life expectancies around 80% of normal life expectancy,” write the authors.
Starting treatment after 2006 was
associated with improvements in prognosis. Patients initiating therapy after
that date with a baseline CD4 cell count above 200 cells/mm3 had
average life expectancies between 82% and 88% of those in HIV-negative
individuals of the same age and sex.
Further analysis showed that the life
expectancy of patients who survived 24 months after the initiation of therapy
was between 15%-20% higher than individuals who had just started treatment.
The authors note that treatment is now
recommended for all patients before their CD4 cell count falls below 350
cells/mm3. Testing campaigns are also likely to have increased the
proportion of patients able to start treatment before their CD4 cell count
falls to dangerously low levels. The investigators therefore suggest: “Estimates
of life expectancy for adults who have initiated ART with CD4 counts above 200
cells/mm3 may therefore be underestimates of the life expectancies
in the future.”
However, they acknowledge that
antiretroviral treatment programmes in resource-constrained settings still face
formidable challenges. They conclude: “It is…critical that appropriate funding
systems and innovative ways to reduce costs are put in place, to ensure the
long-term sustainability of ART delivery in low- and middle-income countries.”