Timothy Ray Brown, who is believed to be the first person to have ever been cured of HIV, had a message for the room of scientists, advocates and journalists who'd gathered to hear him speak at the International AIDS conference in Washington, D.C., Tuesday.
His message: He is still free of the virus that causes AIDS.
"Let me be clear. I am HIV-negative," Brown told a news conference.
Brown, famously known as "the Berlin Patient," responded directly to a controversy that arose recently when tissue samples from his blood cells, plasma and rectum showed evidence of HIV when tested.
Steven Yuki at the University of California, San Francisco, and one of the scientists who'd tested Brown's samples, expressed doubts during a June 8 talk at the International Workshop on HIV and Hepatitis Virus in Sitges, Spain.
"There are some signals of the virus, and we don't know if they are real or contamination," Yuki said in June, "and, at this point, we can't say for sure whether there's been complete eradication of HIV."
Nevertheless, Brown said he had been off anti-retrovirals now for five years, and was doing well.
Brown's story -- arguably one of the most followed in the realm of HIV research -- began in 1995 when he was diagnosed with HIV while attending school in Berlin. For the next 11 years, doctors treated him with anti-retroviral therapy, to which he responded positively.
In 2006, however, Brown's health deteriorated. He was diagnosed with acute myeloid leukemia -- and underwent chemotherapy. While the first round of treatment appeared to work, it also made him more susceptible to infections. Brown developed pneumonia early on in his treatment, and he battled sepsis halfway through his third round of chemo. His doctors realized they would have to try a different approach.
His oncologist, Dr. Gero Hutter of the Charite Hospital in Berlin, opted to give Brown a stem cell transplant to treat his leukemia. But rather than choosing a matched donor, he used the stem cells of a donor he found who had what is known as a CCR5 mutation -- a mutation that makes cells immune to the HIV. In results later published in the New England Journal of Medicine, Hutter and his colleagues reported that the transplant not only treated Brown's leukemia but had also eliminated the HIV from his system.
Brown stopped taking his anti-retrovirals the day of the transplant, and he said he has never needed them since. The only drawback of his treatment is that he has endured some neurological damage. "There was a period after my transplant when I couldn't even walk," he said.
Brown's body no longer harbors HIV, whereas once he had a full-blown infection. Some may recall reports of children who carry antibodies to HIV because they were born to HIV-infected mothers, because the antibodies passed easily across the placenta from mother to child. These children are placed on anti-retroviral medication to try to prevent the infection. If successful, the mother's antibodies are eventually lost but because the child was never infected with the virus itself, this does not represent a "cure." To this date, Timothy Brown believed to be the only known patient who was once infected with the virus and now potentially no longer is.