Mar 5, 2013

Why First 30 Hours Critical for Killing HIV

News that a baby seems to have been functionally cured of HIV after early intervention has piqued the interest of the medical community worldwide and raised hopes that the procedure could be used to more easily and effectively prevent mother-to-child transmission of the virus. More than 3 million children are currently living with the virus that causes AIDS.

Doctors made the announcement Sunday at the 20th annual Conference on Retroviruses and Opportunistic Infections (CROI) in Atlanta.

The timing of the intervention -- about 30 hours after the baby was born -- may have been the key to success, doctors involved with the case said.

“Early treatment most likely contributed to the outcome of this child, but whether it's the only intervention that allowed this outcome is unclear and requires further study,” said Deborah Persaud, associate professor at Johns Hopkins Children’s Center and author of the report on the baby.

The current procedure for high-risk infants is a regimen of smaller doses of antiretroviral drugs until a blood test confirms HIV when the baby is six weeks old. But knowing that this baby was at high risk, Dr. Hannah Gay decided not to wait for the results, and started the baby on high doses of three standard drugs used for HIV-positive babies as soon as the baby was transferred to her at the University of Mississippi Medical Center. The child is now 2 ½ and has no signs of the functioning virus.

While pediatric AIDS researchers were surprised, and while they reiterate the need for the procedure to be repeated, they said it makes sense that the treatment worked. Persaud offered one hypothesis that she and Dr. Katherine Luzuriaga, an immunologist at the University of Massachusetts, plan on testing in clinical trials in the next few months: The HIV virus usually establishes itself in reservoirs where it stays in a dormant state.

“One can imagine if you can halt virus replication very quickly in an infant through the use of very early antiviral therapy,” Persaud said, “that what we've accomplished with this is that the reservoirs are not given the opportunity to be established.

Researchers suspect that those viral reservoirs might be different in children than in adults, Luzuriaga added.

“If we start early, we appear to be able to control viral replication extra tightly and we end up with lower amounts of the viral reservoir,” Luzuriaga said.

Early detection and treatment of diseases is something Dr. Josh Petrikin is familiar with as a neonatologist at Children’s Mercy Hospital in Kansas City, Missouri.

“Depending on the diagnosis, it can be critical -- even life-saving” to start treatment early for a variety of diseases, he said.

All babies in the U.S. get some form of newborn screen, testing for up to 70 various diseases and conditions depending on the state -- nearly all of which can be affected by an early diagnosis. HIV isn’t included on the screen, but the American College of Obstetricians and Gynecologists recommends screening for pregnant women. In the future, genomic medicine could replace the current screening protocol, Petrikin said. Like many others, he’ll be watching for published work on the potential HIV cure.

Read more at Discovery News

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