A fifth patient has been designated cured of HIV after he’s gone four years without a sign of the virus in his system following a stem cell transplant from a donor with an HIV-resistant mutation in their DNA, ABC News reports.
While the treatment has been successful, its widespread application is unlikely due to cost and risk to the patients. The patient with HIV must undergo treatment to completely obliterate their immune system so that the stem cells can essentially rebuild the patient’s immunity from scratch.
The stem cell treatment is a treatment of last resort for some types of cancer, but in each of the cases for HIV patients, the donors had an HIV-resistant mutation found in just 1% of people that deletes a protein called CCR5 that the virus uses to penetrate cells, allowing it to multiple.