Timothy Brown made medical history when, after a bone marrow transplant, all traces of HIV in his system seemed to be eradicated, leading to wide scientific debate and excitement. Now, Brown is again the subject of scientific inquiry after tests show there may after all still be traces of HIV in his body.
But new data presented last week in Spain raise a question about whether there are minute traces of HIV in some tissues–not whole virus capable of replicating, but pieces of viral genes.
Researchers have combed through 9 billion of Brown’s cells, retrieved from his blood, lymph nodes, spinal fluid and intestinal tract. Four different labs could find no trace of HIV in his blood cells. But three groups, using tests at the very limit of detectability, think they have identified bits of HIV genetic material — two from blood plasma and one from intestinal cells.
“Although the subject has had intermittent evidence for HIV persistence in some assays in some laboratories,” the researchers wrote in a summary, “the extremely low levels of virus which were detected, while pushing the limits of sensitivity and specificity … make it impossible to conclude that the subject remains HIV-infected.”
What does the appearance of HIV-infected cells mean for Ray’s cure?
While some doctors have now begun to speculate that Brown may have been reinfected with the virus, they remain in a minority.
Others have suggested that the new findings are in fact due to contaminated lab conditions, pointing out that the cell fragments do not completely match the HIV strain Brown was originally infected with. Indeed, Douglas Richman of the University of California, San Diego, is quoted as saying, “If you do enough cycles of PCR (polymerase chain reaction), you can get a signal in water for pink elephants.”
However, the majority of scientists, while highlighting that Brown’s case is unprecedented and so any talk surrounding what might be going on must be taken as theorizing, wish to focus on the fact that even if there are traces of the virus in Brown’s system, they are not actively capable of replicating. This means that, functionally speaking, the Berlin patient’s cure is still active: Brown’s HIV symptoms were eradicated with the bone marrow transplant and have yet to return.
Indeed, the scientist who presented the findings at a HIV/AIDS talk in Spain, Steven Yukl of the University of California, San Francisco, has accused the media and some other scientists of misrepresenting what his team presented.
According to the AFP, Yukl had in fact been very careful to characterize the findings as indicative that further research will be necessary:
Yukl “highlighted the difficulties that they and several labs they collaborated with have had determining if Brown truly had eradicated the virus from his body,” said the ScienceInsider report.
“There are some signals of the virus and we don’t know if they are real or contamination, and, at this point, we can’t say for sure whether there’s been complete eradication of HIV,” Yukl was quoted as saying by ScienceInsider.
Timothy Brown, 45, was the recipient of several bone marrow transplants in Berlin in 2007 and 2008 to treat leukemia. The blood cells used during the transplant came from a donor with a genetic mutation that made his cells immune to HIV. Around 10% of Caucasions are thought to be immune to HIV. Just how this immunity comes about is not yet fully understood, though recent research confirms the suspicion that a mutation of the gateway protein CCR5 is at least partially involved. The patient used in Brown’s case did have the CCR5 mutation, and when scientists returned to Brown’s test results post-transplantation they were shocked to discover he remained without viral rebound, even after discontinuation of antiretroviral therapy. Brown, to this day, continues to live free of HIV symptoms.
This led scientists to declare in 2010 that a cure for HIV had been achieved, whereby they set about attempting to analyze and replicate the conditions that led to Brown’s cure.
This new information, while the subject of great media interest and scientific debate, may be important then as it could allow scientists a clue to exactly what process occurred in Brown’s body to bring about the eradication of HIV symptoms.
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