June 14, 2012
The "Berlin patient" is sharing his story today at the Prevention and Outreach Summit, a free event Philadelphia FIGHT is sponsoring at the Convention Center. When Timothy Brown was seriously ill in Berlin with acute myeloid leukemia and HIV in 2006, his doctor proposed a bone-marrow transplant and found a donor whose marrow carried a mutation that blocks HIV from infecting human cells using the CCR5 receptor.
Since that first transplant, Brown has remained HIV-free, but the dangerous procedure he underwent remains unviable for most HIV patients. Even so, those suffering another life-threatening disease with HIV might benefit from a collection of 102 cord blood stem-cell samples that carry the mutation, which Lawrence Petz, chief medical officer of California-based StemCyte, hopes can grow to 300 samples. HIV patients needing a stem-cell transfusion could search them for a match, he said, noting that cord blood stem cells work like bone marrow stem cells but are easier to match.
Another approach is genetically modifying cells to have the mutation. Scientists including Carl June of the University of Pennsylvania are working with "zinc finger nucleases" that behave as molecular scissors that can snip out the receptor.
Last week, scientists reported there could be inactive, broken pieces of virus in Brown's blood, the first time a trace has been found since his case became famous. However, some researchers question the findings, proposing that the samples had been contaminated.
"I don't have to take medication and the virus isn't doing anything to my body," said Brown, whose "functional cure" means his immune system is working normally and the virus is not replicating even without treatment. Brown says the question remains open whether or not he has a "sterilizing cure," in which all traces of virus are absent from the body.