(Medical Xpress)—In a Canadian research collaboration, clinicians and
scientists at The Hospital for Sick Children (SickKids), Children's
Hospital of Eastern Ontario (CHEO), Sainte-Justine University Hospital
Research Center (CHU Sainte-Justine), and Université de Montréal teamed
up to investigate the impact of treating newborns, whose mothers did not
have full suppression of their HIV during pregnancy, with combination
antiretroviral therapy within 72 hours of birth.
The study, published in the June 9 online edition of Clinical Infectious Diseases,
was initiated after news in March 2013 reported that an HIV-infected
infant in Mississippi, who had been on the same early combination treatment, had been apparently cured of the virus.
The study found that in some HIV-infected children, starting antiretroviral treatment
soon after birth reduced the size of HIV reservoir in the blood to
undetectable levels. The research team cautions however that it is too
soon to know whether these children have been functionally cured.
The research team reviewed the charts of 136 children who received treatment doses of combination antiretroviral therapy
within 72 hours of birth. Of these, 12 children were confirmed to be
infected with HIV. Eight of the 12 had ongoing evidence of active
infection based on detection of the virus in standard viral load blood
tests. All of these eight children had a history of incomplete adherence
to therapy at some time during follow up. The remaining four children,
all very adherent to therapy, achieved and have maintained an
undetectable viral load for three to seven years. These four had a
series of highly sensitive tests done in an attempt to detect latent
virus in blood cells. In three of the four, no latent virus could be
detected. In the fourth, virus was cultured from blood cells at an
extremely low level (0.1 infectious units per million cells).
The findings of the study have several important implications
pertinent to the management of newborn infants at high risk of HIV
infection. "Our findings suggest that starting combination treatment
within 72 hours of birth may significantly reduce the amount of HIV in
the body," says Dr. Ari Bitnun, lead author of the study and Physician
in Infectious Diseases at SickKids. "However, stopping treatment may be
the only way to determine whether these patients have in fact been
cured." This is because the virus may be present in latent form within a
very small number of cells that cannot be detected even with the most
sensitive tests available. The team is unanimous that more investigation
is needed before considering stopping treatment. If viable latent virus
is present, even in minute amounts, it is likely to reactivate after
stopping treatment and this could be harmful to the long-term health of
these children.
The findings of the study also have implications for HIV cure
research in perinatally-infected children, demonstrating that early
initiation of treatment may be the key to reducing the virus to
virtually nothing. This observation extends the findings of previously
published studies involving both adults and children that showed that
starting treatment within months of infection is associated with lower
levels of latent virus in cells compared to those who begin treatment
later.
Another important finding was that all three children, in whom no
virus was detected, had genetic markers that were previously associated
with better HIV control in adults. "This suggests that in early treated
perinatally-infected children, the infant's genetic make-up may
contribute to how well HIV can be controlled," says Dr. Hugo Soudeyns,
Researcher at CHU Sainte-Justine and Chair of the Department of
Microbiology, Infectiology and Immunology at Université de Montréal.
"What is very important for the families of children
living with HIV to remember is that this research, while very exciting,
is still in its early stages and any talk of a cure for HIV is
premature," cautioned Dr. Jason Brophy, staff physician at the
Children's Hospital of Eastern Ontario and principle Knowledge User for
the team. "We would not want families to become so excited about these
findings that they stop their child's medications without consulting
their physician. We hope to provide clear information to the community
affected by HIV at every step of the way on this path of paediatric HIV
cure research."
While this study presents new implications for further research into a
cure for HIV-infected infants, the team emphasizes the importance of
preventing HIV-transmission from mother to baby by ensuring that all
pregnant women are tested for HIV. "If appropriate treatment is provided
during pregnancy and delivery, we can virtually eliminate the risk of
transmission from mother to child which would eliminate the need to
aggressively treat newborn infants with combination antiretroviral
treatment in the first place," says Bitnun and the team.
http://medicalxpress.com/news/2014-06-treatment-hiv-infected-infants-virus-undetectable.html
