Growth Hormone May Stave Off AIDS
Treatment Boosts Infection-Fighting Immune Cells
July 26, 2005 (Rio de Janeiro, Brazil) -- Growth hormone may help to stave
off AIDS, research shows.
In a new study, growth hormone injections stimulated the production of
immune system cells that can help the body fight infection, says Kimberly
Smith, MD, MPH, associate professor of medicine at Rush University Medical
Center in Chicago.
The researchers looked at immune cells known as CD4 T cells, which are
destroyed by HIV. As the number of disease-fighting CD4 cells drops,
HIV-infected persons lose their ability to fight off infections related to
Smith's study, presented here Tuesday at a meeting of the International AIDS
Society, included 54 HIV-infected persons who had poor immune system function
despite treatment with standard AIDS medications.
"Antiviral drugs controlled the amount of virus in their blood, but
these people still had an inadequate immune response with a low CD4 cell
count," Smith tells WebMD.
Smith added growth hormone to their treatment plan after animal studies
showed that it boosts thymus function, which is involved in production of CD4
About half the people got growth hormone injections plus their usual HIV
medications for 48 weeks. The others continued their HIV drugs alone for 24
weeks followed by growth hormone injections for another 24 weeks.
Growth hormone treatment increased average CD4 cell counts by 15% to 20% by
the end of the study, she says.
More importantly, growth hormone was associated with a 50% to 60% rise in
so-called naive CD4 cells -- a specific type of CD4 cell "that is important
for fighting viruses that the body never saw before," Smith says.
Side effects of the treatment, while infrequent, included body aches and
liver enzyme abnormalities.
Growth hormone is typically prescribed for children whose pituitary glands
do not make amounts of the hormone sufficient for normal growth.
Hope for Restoring Embattled Immune Systems
While the study offers hope that growth hormone can stimulate the thymus to
produce CD4 cells and help restore ravaged immune systems in HIV-infected
people, it's way too soon to recommend the treatment, Smith says.
First, larger numbers of people need to be followed for longer periods of
time to see if growth hormone actually keeps AIDS-related infections at bay,
Albert Duarte, MD, PhD, associate professor of medicine at the University of
Sao Paulo in Brazil and moderator of the session at which the findings were
announced, says that while the results are promising, he thinks that growth
hormone is too costly to use as an anti-AIDS medication.
But if the findings pan out in future studies, they could pave the way to
the development of an immune-boosting vaccine to treat people with HIV
infection, Duarte says.
"Stimulating the thymus to produce T cells may be a viable vaccine
strategy," he tells WebMD. "But because growth hormone is very
expensive, there's no room for it now."
Smith acknowledges the high price tag, although she points out that people
in the study got a much lower dose than is typically prescribed to children
with growth hormone deficiency. She estimates that the cost of treating a child
with growth hormone deficiency is about $5,000 a year.