Bone
Marrow Transplant Eliminates Signs of HIV Infection, Offers Insight into Cure
Two BWH patients with longstanding HIV
infections no longer have detectable HIV in their blood cells following bone
marrow transplants, according to BWH researchers. The research offers
insights into how a cure for HIV might be developed, although it is too soon to
say if the men are cured.
The virus was easily detected in blood
lymphocytes of both men prior to their transplants but became undetectable by
eight months post-transplant. The men have remained on anti-retroviral
therapy.
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Daniel Kuritzkes, MD
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"This gives us some important
information," said Daniel Kuritzkes, MD, chief of the BWH Division of
Infectious Diseases, who presented the case with Timothy Henrich, MD, at the
International AIDS Conference in July. "It suggests that under the
cover of anti-retroviral therapy, the cells that repopulated the patient's
immune system appear to be protected from becoming re-infected with HIV."
One patient's bone marrow transplant was two
years ago; the other was four years ago. Both were performed at the
Dana-Farber/Brigham and Women's Cancer Center. Over time, as the
patients' cells were replaced by donor cells, traces of HIV were lost.
Currently, both patients have no detectable HIV DNA or RNA in their blood.
The level of HIV antibody, a measure of exposure to HIV, also declined in both
men.
"We expected HIV to vanish from the
patients' plasma, but it is surprising that we can't find any traces of HIV in
their cells," said Henrich. "The next step is to determine if
there are any traces of HIV in their tissue."
The research team is currently designing
studies that would enable them to look for HIV in the tissues.
Researchers also plan to study additional HIV-positive patients who have
undergone a bone marrow transplant.
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Timothy Henrich, MD |
Researchers point out that there are two key
differences between the BWH patients and the "Berlin patient," a man
who was functionally cured of HIV after a stem cell transplant. In the Berlin
patient's case, his donor was specifically chosen because the donor had a
genetic mutation that resisted HIV. The BWH patients' bone marrow
transplants were done without any thought to selecting an HIV-resistant
donor. Second, the Berlin patient ceased anti-retroviral therapy after his
transplant, while the Brigham patients have remained on anti-retroviral
therapy.
This research was
supported by the AIDS Clinical Trial Group, the Harvard Center for AIDS
Research and the National Institute of Allergy and Infectious Disease.