Next, to accommodate the donor’s immune cells, they had to wipe out Mr. Brown’s own immune system by bombarding him with chemotherapy and radiation. Next came the transplant procedure itself. On that same February day, Mr. Brown stopped taking his antiretroviral medication. Three months later, after a grueling recovery in which he almost died, he was H.I.V.-free.
For Mr. Brown, the epiphany came one day in the gym, when he found that he was developing muscles again after years of wasting away. “That was kind of my proof that it was gone,” he said.
Many hurdles remained. A recurrence of leukemia required a second transplant a year later. A brain biopsy left Mr. Brown temporarily paralyzed and nearly blind. He had to be taught how to walk and talk again. His recovery, complicated by injuries from a 2009 mugging in Berlin, left him with a stiff shoulder, limited vision and neurological damage, which prevented him from resuming his work as a translator.
“My life is far from perfect,” he said in 2015, “but it is still my life.”
He was living in Nevada in 2013 when he met Mr. Hoeffgen on the Scruff dating app. They moved to Southern California in 2015. In April, Mr. Brown was admitted to a cancer hospital; his leukemia, unrelated to H.I.V., had returned. Covid-19 restrictions kept the couple together on the medical campus for weeks.
This month, Mr. Hoeffgen told Mark S. King, a blogger and AIDS activist, that Mr. Brown had terminal cancer and had been receiving home hospice care. Mr. Brown was aware that he was dying.
“I have asked him what he wants me to tell people when we make his situation public,” Mr. Hoeffgen said. “He said: ‘Tell people to keep fighting. Fight for a cure for H.I.V. that works for everyone. I never wanted to be the only one.’”
In addition to Mr. Hoeffgen, Mr. Brown is survived by his mother.
One researcher asked whether the couple would consider donating Mr. Brown’s body to science.
“I said, ‘Thank you, but no,’” Mr. Hoeffgen said. “‘I think he’s done enough.’”