About 1 percent of people descended from northern Europeans have inherited the mutation from both parents and are immune to most HIV. The transplant in this patient case destroyed the cancer without harmful side effects, while the transplanted immune cells, which are now resistant to H.I.V., seem to have fully replaced his vulnerable cells. There is still no trace of the virus after 18 months off the drugs. Lead researcher Ravindra Gupta of University College London said the fact the man has been HIV free for 18 months was ‘an improbable event’.
Previously, another similar patient case occurred in Berlin. Such transplants are dangerous and have failed in other patients. They’re also impractical to try to cure the millions already infected. Stem cell transplants typically are harsh procedures which start with radiation or chemotherapy to damage the body’s existing immune system and make room for a new one. But the success now confirms that a cure for H.I.V. infection is someway possible, if difficult, researchers said.