(CNN) HIV has returned in two patients who doctors hoped had been cured of the virus following bone marrow transplants, the Boston researcher who treated them said Saturday.
The HIV virus became undetectable in both patients approximately eight months after the transplant. The men remained on antiretroviral therapy until the spring of 2013.
"The return of detectable levels of HIV in our patients is disappointing, but scientifically significant," Dr. Timothy Henrich, a researcher at Brigham and Women's Hospital in Boston, said in a statement. "We have demonstrated HIV can be reduced to undetectable levels by very sensitive research assays and the virus persists."
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