In Life, Man Immune To HIV Helped Scientists Fight Virus

Stephen Crohn, a man best known for staying alive during the early days of the AIDS epidemic, died Aug. 23 at age 66. Throughout his lifetime, the New York artist helped researchers uncover vital clues about HIV and how to stop it.

Crohn's partner was one of the first people to die from AIDS in 1978. Over the years, Crohn watched boyfriends and acquaintances die from the disease. But he never got sick.

Knowing that there was something unique about himself, Crohn volunteered to be studied.

Eventually, scientists realized that Crohn had a genetic anomaly that made him resistant to HIV infection. Less than 1 percent of the population carries this protective mutation.

Immunologist Bill Paxton was one of the first scientists to work with Crohn at the Aaron Diamond AIDS Research Center in New York. He figured out that some of Crohn's immune cells, called CD4, literally blocked the virus. "I couldn't infect the CD4 cells," he told The New York Times. "I'd never seen that before."

HIV normally enters an immune cell by tugging on two receptors on the cell's surface. Scientists ultimately figured out that one of those receptors on Crohn's cells was shortened and not accessible to the virus. Without the receptor, HIV could't infect his cells.

This genetic change is called the delta 32 mutation. Its discovery has helped researchers develop the anti-viral drug maraviroc and devise the first experimental strategy for curing HIV.

Crohn was an artist and freelance editor. His paintings have been exhibited in New York, San Francisco and elsewhere. He committed suicide last month. His sister, Amy Crohn Santagata, told The New York Times that he suffered from survivor's guilt.

NPR's All Things Considered host Audie Cornish recently spoke with Paxton, who remained friends with Crohn over the years.

Can you tell us how you first met Stephen Crohn, because I gather it was part of your research of AIDS-resistant men?

Yes. This was back in 1994. I was setting up a study. I wanted to look at people who were highly exposed to HIV, but who had remained seronegative so they hadn't contracted the virus. And through a meeting, an HIV activist put me in touch with a couple of doctors ... Within a week I had a phone call from [one doctor] saying, 'I have the perfect person to fit with what you're looking for.' And that's when I was introduced to Steve.

By the 1990s, what were the medical options for AIDS patients. How far had the research really come?

Well, treatment was not really an option, and really back in the '90s, AIDS still was a disease to be reckoned with. It still was at its peak. It was still rising.

Talk a little bit about how Crohn came to the medical community. I mean, how did he view his role in all of this.

Well, I mean, Steve was quite phenomenal. When I met him, we clicked instantly. There was a rapport between us. He understood, you know, before scientists that he had this resistance to AIDS. He said, 'I have this protection. I have something. Study me.'

And he just had this empathy for the science. He understood it. And it helped that we had the same sense of humor. He was a real fun character. And he persevered with the study. He came back, he came back, he came back.

And I think the thing which for me was most striking was at the end, we could say to Steve, 'You were right. And you have this molecule missing. That is advancing science.' And I think Steve took a lot from that. Through all the misery, actually at the end, from studying him and people like him, we actually did move HIV research forward. And there are drugs out there now which, from Steve's findings, are highly beneficial to stop the virus from replicating.

Stephen Crohn's death was tragic. It was a suicide. And his sister has said that he may have been overwhelmed by survivor's guilt. Did you get any sense of that at times, or have any understanding of how he felt surviving all of his friends?

It is very traumatic. I think he told me once that he had lost 80 or 90 good friends. Week after week, you're going to memorials, you're going to funerals. That's just daunting. That's a daunting task.

My feeling was that back in the '90s, when this discovery was made, I think Steve took a positive from it. I think Steve felt that he himself had contributed to the struggle. But I seriously, I wouldn't like to comment on what role this aspect of Steve's life played on, you know, the tragic end.