September 21, 2014
Given how much the phrase "HIV cure" has been thrown around, you might start to think that we actually have one.
We don't. But we're getting closer.
Over the past few years, a tiny -- but slowly growing -- number of people appeared to have had active, living, reproducing HIV completely eliminated from their bodies. We say "appeared" because most of these individuals ultimately relapsed. However, there was a period of sustained remission that needs to be studied more.
This is uncharted territory, and researchers are still working hard to find ways to eradicate HIV or prolong the remission seen in some of these extraordinary cases. For that reason, we tend to refer to people with no sign of HIV in their bodies not as "cured," but as "functionally cured."
Here's a quick look at the most solidly documented "functional HIV cure" cases we know of today.
The "Berlin Patient"
In the beginning, there was Timothy Ray Brown. An American living in Berlin, Brown was diagnosed with HIV in 1995 -- and with advanced leukemia in 2006. His prognosis had become grim.
A German oncologist, Gero Hütter, M.D., decided to try the medical equivalent of a Hail Mary pass: A never-before-attempted stem cell transplant in which the donor had a rare mutation making him essentially immune to most forms of HIV.
The procedure was extremely risky -- and stunningly successful. Brown's leukemia remains in remission, and there is still no sign of active HIV anywhere in his body, though he has been off of HIV medications since shortly after his transplant.
The Boston Duo
The success of the "Berlin patient" got researchers wondering: How easy might it be to replicate this miracle?
The short answer is: not easy. The stem cell transplant procedure is very dangerous, and awfully expensive. Nonetheless, in certain cases it may be deemed worth the risk. In 2012, researchers reported the cases of two HIV-positive men who had received stem cell transplants similar to the one Brown received. Unlike Brown, though, the donor cells they received were not resistant to HIV; finding a genetic match for such a rare mutation is extremely difficult.
The two men stayed on HIV treatment throughout the transplant process, which appeared to have kept any remaining HIV in their bodies from infecting the new donor cells. Unfortunately, months after stopping treatment, both patients relapsed.
The VISCONTI Cohort
For some time now, many HIV experts have had a hypothesis: If people can be started on HIV treatment early enough -- very shortly after they are infected -- it might be possible to prevent HIV from establishing a permanent foothold in their bodies.
The VISCONTI study is one high-profile attempt to test this hypothesis. Fourteen people who started HIV treatment during acute (early-stage) infection were kept on medications for at least a year before stopping.
Surprisingly, once they stopped treatment, these people were still able to control the virus -- their HIV viral load remained undetectable without them having to take meds, as though their immune systems had been "trained" to be similar to that of the extremely small number of people who appear to have a natural ability to fight off the virus.
Doctors refer to these people as being "post-treatment controllers," or in "long-term functional remission" of their HIV infection.
The "Mississippi Baby"
One of the most popular "cured" stories came in March 2013. That's when we learned about a baby from Mississippi who had HIV at birth, but whose infection appeared to have subsequently been wiped out.
Similar to the VISCONTI group, the key to success in this case appeared to have been starting HIV treatment very early with the most potent drugs available. This is not typically necessary for babies born to HIV-positive mothers, in part because mothers rarely pass HIV to their children if they receive proper care before giving birth.
After being taken off treatment, the child showed no signs of HIV for 27 months. However, in July 2014, the child's virus rebounded.
While disappointing, the case could provide some critical insight if scientists are able to determine what it was that prevented HIV from rebounding for 27 months even though the child was not on treatment, as well as what triggered the rebound.
The Minnesota Pre-Teen
In April 2013, news arrived about a 12-year-old boy in Minnesota, Eric Blue, who had received a stem cell transplant using HIV-resistant donor cells to treat his HIV and leukemia.
Sound familiar? It should. It's the same procedure Timothy Ray Brown underwent, except the doctors used umbilical cord blood, which is easier to match to a recipient.
The transplant operation itself was completed without complications, and Eric was reportedly doing well until June 2013, when he developed graft-versus-host disease. Sadly, he passed away on July 5, 2013.
"While not yet conclusive, tissue and blood tests obtained through Blue's treatment have shown an absence of HIV, even after his medications were discontinued," his doctor said.
2 Men Down Under
Two Australian men are showing no signs of HIV after receiving bone marrow transplants to treat cancer, according to a case presented by David Cooper at the 20th International AIDS Conference in Melbourne, Australia.
Although the two patients are seemingly HIV-free, they are both still on antiretroviral therapy as a precaution. As we've seen in the two Boston patients who had HIV remissions after stem cell transplants, the virus can still rebound months after treatment is discontinued, leading to an abundance of caution with these men.
Certainly, this is promising news, but it remains to be seen whether these two Australian patients are truly cured or need to remain on treatment.
The Argentinian Woman
A 51-year-old woman in Argentina appears to be functionally cured after discontinuing treatment for seven years, according to another study presented at the 20th International AIDS Conference in Melbourne, Australia.
The woman was diagnosed with HIV in 1996, started treatment and eventually achieved an undetectable viral load. In 2007, treatment was interrupted because of lipid and body fat problems associated with her medications. Since then, despite being off treatment, her viral load has remained undetectable. What's more, no HIV DNA has been detected in her blood, and she does not have the CCR5 receptor mutation.
Researchers report that this could be a case of a functional cure and suggest that it may even be possible to achieve this state using standard HIV treatment, although this has never been known to have occurred before. Further studies are underway to examine the woman's HIV reservoirs.
Read More on the Cure
If this slide show has piqued your interest and you want to learn more about the search for a way to stop HIV once and for all, take a look at the following articles: