July 3, 2013
Two Boston Patients HIV-Free Following Dangerous Bone Marrow Transplant
Brett Smith for redOrbit.com - Your Universe Online
After a series of grueling and risky treatments, two HIV-infected patients from Boston have tested negative for the virus after stopping their daily regimen of antiretroviral drugs, according to an announcement made at an international AIDS conference on Wednesday.
Doctors credit the phenomenon to bone marrow transplants the patients received several years ago to treat advanced-stage blood cancer.
"I don't want to use the 'cure' word," Dr. Timothy Henrich, an infectious diseases expert at Brigham and Women's Hospital who is leading a study on the patients, told Boston.com, a subsidiary of the Boston Globe. "If they remain virus-free in a year, or even two years, after [stopping] therapy, then we can make a statement that the chances of the virus returning are very low."
The findings do not translate easily to treatments for other individuals with HIV as the method used for the Boston patients involves a dangerous weakening of the immune system before the transplant operation. With a 15 to 20 percent risk of death, the bone marrow procedure is so dangerous, it is considered unethical to carry it out on anyone not already at immediate risk of dying from cancer.
Both patients had been suffering from Hodgkin's lymphoma, a cancer of the blood. After other cancer treatments failed, the doctors transplanted healthy bone marrow into the patients in an attempt to purge cancerous blood cells in favor of healthy cells. Besides remaining cancer-free, the doctors found the patients' blood also showed no traces of HIV, which the medical team had detected just prior to the operation.
The Boston outcomes are similar to the case of Timothy Ray Brown, the so-called "Berlin patient" who is thought to be the only person cured of HIV. Doctors credit Brown's outcome to bone marrow he received from a donor who carried a rare genetic mutation known as CCR5-delta32. This mutation is believed to provide resistance to HIV by creating CD4 cells - white blood cells that lack a certain receptor HIV uses to access and destroy the cell.
However, the donors in the two recent Boston cases did not have this mutation, suggesting another potential mechanism for HIV removal.
Focusing on the HIV aspects of the two patients' health, Henrich said his team worked in concert with cancer specialists, research observers and outside experts. He added that the patients were notified of the risks involved and were not influenced to participate in his study.
"This is unknown territory and we made that very clear to the patients, who are both very curious to know if they still have HIV in their bodies," Henrich said.
The two unidentified patients were said to be anxious, yet "very positive" about continuing their role in the research without the use of antiretroviral drugs.
"They have been taking antiretroviral therapy for years and years," Henrich said, "and all of a sudden their research doctors are telling them to stop taking it."
Both the patients and doctors agreed the antiretroviral regimen would resume if there are any indications the virus has returned.