Steps Toward HIV Cure

　　This year’s International AIDSSocietyConference on HIV Pathogenesis, Treatment and Prevention,held in Kuala Lumpur, Malaysia, made major headlineswhen Timothy Henrich, an American doctor, announcedthat two more cancer patients may have beencured of HIV after receiving bone-marrow transplants totreat lymphoma. Both patients had been taking retroviralmedication, and continued to do so after the transplantsas their viral levels sank until doctors were unable to findany traces of HIV in the patients’ blood. The doctors thenconsulted with the patients before stopping their HIVtreatments, but have remained watchful, regularly performingblood tests to check for the reappearance of HIV.

　　Unlike the Berlin patient, the first person tohave beencured of HIV through bone-marrow transplantation, thesepatients did not receive bone marrow from donors witha genetic resistance to HIV. While this may open the doorto providing more HIV-infected cancer patients with apotential cure, doctors are remaining cautious. They areconcerned that the patients could still have undetectedreservoirs of HIV in their bodies and that the virus couldonce again attack the patients at a later date.

　　The research group monitoring the patients believesthat the transplanted bone-marrow cells may have playeda role in destroying HIV reservoirs in the patients’ bodiesby attacking the patients’ infected cells in a phenomenonknown as graft-versus-host.

　　Dr. Henrich explained, “For six to nine months afterthe … transplant, we see a mingling of the donor and hostcells, and what happens over time is that the donor cellsclear out the host cells. The peripheral blood lymphocytesthat it clears out are a major reservoir for HIV.”

　　This destruction of HIV reservoirs by donor cells, coupledwith antiretroviral therapy that protected these newcells from being infected with HIV, may have led to whatdoctors refer to as a “functional cure” (a patient no longerneeding treatment for HIV, regardless of HIV infection) inboth of these patients.

　　More hopeful, if tragic, news came from a case inMinnesota where Eric Blue, a 12-year-old boy fighting HIVand leukemia, died on July 5 from complications causedby a cell-transplant along the lines of the one given tothe Berlin patient. In April, Blue was given transplant cellsfrom a donor who was resistant to HIV in a move that wasmeant to combat the HIV and cancer in his system.

　　The transplant seemed to be doing its work asBlue’stest and tissue samples showed no trace of leukemia andHIV, and remained clean after doctors stopped administeringhis HIV medications.

　　Sadly, bone-marrow transplants carry a significant riskof complications, and the transplanted cells began to attackBlue’s body, giving him a severe case of graft-versushostdisease that eventually proved fatal.

　　But doctors explained that not performing the transplantwas not an option. Dr. Michael Verneris, the doctorwho treated Blue, said, “This patient absolutely neededto have this transplant. And if he hadn’t developed a verycommon side effect of bone-marrow transplant and diedfrom it, we were hopeful this was all going to work well.”

　　Despite the death of their patient, the doctors and researcherswho cared for Blue have gained valuable knowledgefrom his treatment that they will be able to use tohelp other cancer and HIV patients in the future.

　　By Katherine Damer