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Dr. Laurence, what tests were done to confirm that there was no HIV left in the Berlin man's body?
An article was published about this patient a few months ago in The New England Journal of Medicine.1 Just before the article was published, I organized a think tank sponsored by amfAR at MIT [Massachusetts Institute of Technology]'s Endicott House, where we got together scientists from around the world, including Dr. Hütter, to talk about what additional tests could be done apart from what had already been done in Germany.
For example, in The New England Journal of Medicine article, it mentions that before that transplant, the patient had an undetectable viral load. Of course, he was on drugs. When he was taken off the drugs, he still had an undetectable viral load, but the tests that they were using are the standard kinds of tests that a person with HIV might get when he or she walks into a doctor's office (i.e., tests that can't detect less than 50 copies of virus in 20 drops of blood).
One of the scientists that I invited to this meeting said, "50 copies per 20 drops? I can get less than a third of a copy of virus in 20 drops." So we had that scientist test the patient's blood and it was negative. So there is no virus by the most sensitive ways that you could possibly look for virus.
Did you also give this man an antibody test?
That's very important. His antibody test would be positive. If you vaccinate someone, say, against the measles or polio and test them for antibodies a year or five years later, he or she will be positive for antibodies. But as you start getting on in time from that initial vaccination -- and it's why we give boosters against certain diseases -- the antibody levels fall off. And that's what's happening to this patient.
It has been about two and a half years since the patient has been off of all of his antiviral drugs and had the transplant, and he still has absolutely no detectable virus, either active virus or latent virus.
His antibody levels -- we call them titers -- are declining just the way you'd expect them to if you'd given someone a vaccination against HIV and then looked at the levels of antibodies. They'd be very strong in the beginning, but would weaken if they are not re-exposed to the virus.
We believe this person has no HIV in his body and therefore there is nothing to re-expose him, so the concentration of HIV antibodies in his blood is decreasing. I predict that, in a couple of years, his HIV antibody test will be negative.
In response to the article that appeared in The New England Journal of Medicine, Dr. Jay Levy -- who's an outstanding AIDS scientist from the University of California in San Francisco [UCSF] -- wrote an editorial titled "Not an HIV Cure, but Encouraging New Directions."5 In his editorial, he said the reason he used the title "Not an HIV Cure" is that there's a lot of evidence from a lot of other studies that HIV can be "lurking" around in cells. What he means is we still wonder: "Could it be in the brain? Could it be in the liver? Could it be in the intestine? Could it be in the stomach?"
This person, I think I mentioned, had a relapse of his leukemia and needed a second stem cell transplant in an attempt to re-cure his leukemia.1 They used cells from the same CCR5-negative donor. After that second transplant, the patient developed complications from the transplant.
He seemed to go through the first transplant with flying colors, though he had a little bit of liver upset, which resolved. But he had many problems from the second transplant itself, which are not unexpected in people who get two transplants.
One of the problems was that he started developing some mental changes. People worried, "Is it related to the transplant? Could it be related to HIV lurking in his brain?"
So he actually had a brain biopsy, in addition to biopsies of his intestines, liver, lymph nodes, bone marrow -- basically, every part of the body that can be biopsied. The best part in answering the Levy editorial was including his brain. All were negative for virus. There is no virus in this person's body out to two and a half years off of all anti-HIV drugs.
This is certainly a functional cure, in the sense that there is no need for anti-HIV drugs and no decline in the patient's immune system. But I would say that, at this point, with all the tests that have been done by scientists throughout the world that I've arranged to have samples sent to, that this patient is as close to a cure as anyone could possibly document -- apart from if the individual were to die and have every single part of every single body organ tested. There is no virus in this person's body.