March 14, 2013

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Hi. This is Dr. Paul Sax from Brigham and Women's Hospital and Harvard Medical School.

As you probably know, the Conference on Retroviruses and Opportunistic Infections (CROI) just took place in Atlanta. The study that undoubtedly got the most attention from that conference was the report of an apparent cure of HIV in a baby born to an HIV-infected mother.[1]

Here are the details of the case. The baby was born to a mother who had not received any antiretroviral therapy during her pregnancy, and the diagnosis of infection in the child was made within 24 hours after delivery. As a result, the people caring for the baby started the baby on a suppressive antiretroviral regimen, first on zidovudine, lamivudine, and nevirapine and then on zidovudine, lamivudine, and lopinavir/ritonavir. They continued this for about 18 months.

The baseline HIV RNA level was just under 20,000 copies/μL. The baby had a nice response to treatment; the viral load rapidly became undetectable. At about 18 months, the baby and the mom were lost to follow-up. When the baby and mom returned at month 23 -- which means the baby had been off treatment for about 5 months -- much to the doctors' surprise, HIV antibody in the baby was negative and HIV viral load was negative.

Further extensive investigations analogous to those done on the famous Berlin patient who has been cured with a bone marrow transplant were done.[2] All of those additional investigations revealed no replication-confident virus and only occasional traces of genetic material consistent with HIV. This is actually the same as in the Berlin patient.

So, the conclusion is that this is really a functional cure in a baby who is still not on treatment, and there has been no viral rebound.

The interesting thing about this case is to consider several questions.

First, is it actually a cure, or was it just an infection that was blocked before it was established? I don't think we really have any way of knowing that right now, but suffice it to say, there's certainly no evidence that the baby has ongoing viral replication.

Does this have implications for our cure research in a broader population? I think it probably does. One of the fascinating postulates is that without memory T cells that the baby doesn't have -- but which we do, as adults -- there was no way to establish a long-lived viral reservoir. That's one possibility.

Does it have implications for us here in resource-rich settings, in places where we have therapy? Well, very few practical implications. As you know, the vast majority of cases of pediatric HIV have been eliminated in this country because treating the mother with antiretroviral therapy makes this whole process unnecessary. Babies born to moms who have been treated and have virologic suppression in the mom have a virtually 0% chance of becoming infected.

The next question is a far more difficult one. Does this have implications for resource-limited settings, where there are thousands, or hundreds of thousands, of babies born to moms who have not received any antiretroviral therapy? Should the standard practice now be to administer a potentially suppressive regimen after birth to the baby for some time-limited period -- maybe 18 months, as was done here, maybe shorter -- in order to try to block the infection from taking place? That's a policy decision and also an interesting research question, and one that I think only time will tell.

That's a summary of the most widely reported presentation from the retrovirus conference. I'll be discussing some other presentations in an upcoming video. Thanks very much.

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