November 14th, 2008
05:59 PM ET
By Miriam Falco
A German hospital announced this week that a 42-year old American living in Berlin who did not want to be identified had come to them three years ago for treatment. It was determined that he had acute leukemia (blood cancer) and was HIV positive too.
After a bone marrow transplant, it appears that not only did the man’s cancer go away, so did the virus that causes AIDS. This has been reported worldwide as a "cure" for AIDS. But even the doctors involved in this case say they don't know if they cured this man of HIV. So what's all the fuss about? Should HIV patients be treated with a bone marrow transplant?
One of America’s top AIDS expert doesn’t think so. "This is interesting but not a practical application. It's not feasible and has extraordinarily limited practical application" long-time AIDS researcher and Director of the National Institute of Allergy and Infectious Diseases Dr. Anthony Fauci told CNN. He and other researchers first learned of this case back in February. But this study of one patient has not yet been published or been reviewed by other AIDS experts. It didn't get much attention back then because of the many limitations it has. Dr. Robert Gallo is one of the scientists who discovered HIV. "While this procedure might help a very small minority of people living with AIDS,” Gallo says, “it is by no means the answer to the world's HIV/AIDS pandemic."
Doctors first began treating the cancer with chemotherapy. They also gave him anti-retrovirals to contain the virus that causes AIDS. Doctors said at a press conference this week that the patient did go into remission, but eventually the cancer came back. The next step to treat the cancer was a bone marrow transplant, which is common for leukemia patients.
His doctors emphasized that without further treatment, without the bone marrow transplant, he would have died of cancer – not HIV or AIDS.
But the patient’s physician, Dr. Gero Huetter, wanted to combine the cancer treatment with something he had heard about in medical school 12 years ago. That’s when researchers found out that a certain genetic mutation prevents the virus from getting into a person’s cells. But to be resistant to HIV, one has to have inherited this mutation from both parents.
So when it came to looking for a bone marrow donor for his patient, Huetter decided to see if he could find a donor that not only was a marrow match for his patient, but one who also had these two copies of the genetic mutation to see if they would get the bonus of treating the HIV, while treating the more urgent need – cancer.
Here's where the German doctors admit they were very lucky. They told reporters they normally find one to five qualified donors for their patients in need of a transplant. In this case they found 80 donors. So they systematically tested each donor for the mutation and when they came to the 61st potential donor they hit the jackpot. Nearly two years after the bone marrow transplant, the patient is still in remission from his cancer and he doesn't seem to have any detectable HIV either.
This is probably why many newspaper headlines interpreted the success as being a cure.
However there are many caveats to this story.
1. Even though their tests do not show a presence of HIV in his system, doesn't mean it's not there. This virus is known for hiding well and popping up later. It's been seen before in patients taking anti-retroviral drugs. It is possible that if more sophisticated tests were used on this patient, they would detect the virus that is still in his body. So it's still not entirely clear that he is HIV-free.
2. The chances of finding a bone marrow donor with two copies of this genetic mutation for everyone one of the 33 million people worldwide living with HIV or AIDS is not realistic because only one percent of Caucasians and zero percent of African Americans or Asians have this particular genetic mutation.
3. Bone marrow transplants are dangerous for patients. Before they can get the donated stem cells that will replace their own, they have to take strong chemotherapy to destroy their own bone marrow - leaving them without an immune system to fight off any disease - until the transplanted bone marrow can make new blood cells. Plus patients run the risk of rejecting the new cells, which means they have to take immune-suppressing drugs for the rest of their life.
4. Bone marrow transplants are very expensive and not an option for many people living with this disease around the world.
Both the doctors in Berlin and AIDS experts we've spoken with say this is a "proof of principle." "It's an interesting case for researchers," according to Dr. Rudolf Tauber, from the Charite hospital in Berlin, where the patient was treated. The hope is that this one case could lead to future treatments. Dr. Gallo says, "If patients living with HIV and AIDS have access and can adhere to today's retroviral therapy, many will live longer, healthier lives, perhaps full length lives."
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