Mar 05 2013

HIV Cure “Game Changer”

The story of a young patient apparently cured of HIV infection, making them only the second case of an HIV cure ever, is buzzing around the internet. It is an interesting and important story, but as is often the case the details are complicated and need to be put into context.

The case was recently presented at a conference, on Retrovirus and Opportunistic Infections. The child was born of an HIV infected mother who did not receive pre-natal care. The mother had high viral loads when she presented for delivery. Not surprisingly, the child was found to be infected shortly after birth, indicating that they were likely infected in utero.

Hannah Gay, a pediatric infectious disease specialist, consulted on the case and decided to treat the infant with higher doses of anti-retroviral therapy (ART) than are typically given. She gave therapeutic doses of ART rather than prophylactic (preventive) doses. She also started the ART drugs earlier than they are typically given, at 31 hours of life.

The child was treated for about 18 months and followed closely. At 18 months, however, the mother had some undisclosed life stress leading them to stop medical follow up for their child. The child was no longer given ART or brought in for medical follow up.

Gay, who was still following the patient, eventually tracked her down (now at about 24 months of age) and made a surprising discovery. Despite 6-7 months of no ART, tests revealed no sign of HIV in the child’s system. Gay was surprised at the result, so double checked everything- the child was truly infected early in life and is truly virus free now.

Follow up detailed examination also revealed no sign of the virus, except for a few tests that reveals tiny amounts of viral RNA and DNA, but no “replication competent” virus. They also demonstrated that the HIV is a typical wild type of the virus, and not a mutated weakened strain. Also, neither the mother nor the child have mutations known to confer HIV resistance.

In the abstract they call this outcome a “functional cure,” which means that the virus has not set up shop anywhere in the body, is not replicating, and will not rebound despite being off ART.

What typically happens with HIV infection is that the virus hides out in reservoirs that are impossible to eradicate. Even when viral loads in the blood are reduced to undetectable levels, the virus remains in these hideouts and can rebound the moment ART is stopped.

What the doctors in this case believe is that the early aggressive therapy with ART reduced the virus to very low levels before it could establish these persistent reservoirs. Therefore when ART was stopped, the virus did not rebound. The immune system was able to keep the virus in check by itself.

This is an exciting case that has significant implications. It seems likely that this will result in a change in the standard of care to early aggressive ART for newborns who were infected at or before birth. Further research is needed to assess the overall safety and efficacy of this approach, but it seems hopeful.

This is not, however, a new cure for HIV or AIDS. I always get a little concerned when I see the word “cure” in the headline of news articles, paired with some serious disease like HIV or cancer. This is not a new treatment for HIV and will not affect most people infected with HIV.

It can have a huge impact on infants infected with HIV, however, and this cannot be underestimated. While only about 130 children per year in the US are infected in this way, in developing countries as many as 1000 children per day are born with HIV.

This approach also could prove hugely cost effective – 1-2 years of ART vs a lifetime of ART and possible complications from HIV. An investment in early treatment would certainly be one worth making.

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