Studies Rebut Controversial AIDS Theory : Medicine: Scientists say they have refuted claims by a respected virologist at UC Berkeley that drug use--not HIV--causes the disease.

Peter Duesberg--a respected virologist and member of the National Academy of Sciences and professor at UC Berkeley--has spent six years promoting his attention-grabbing theories about AIDS. To anyone who will listen, Duesberg has argued that drug use, and not the human immunodeficiency virus, causes the disease.

Now, in two separate papers, scientists in California and Canada say they have refuted Duesberg once and for all.

The first, a commentary published today in the scientific journal Nature, looked at drug use and AIDS among 1,027 San Francisco men and found no correlation between the two. The second, to be published in Saturday’s issue of The Lancet, reports that among 715 homosexual men in Vancouver, those who tested positive for HIV and went on to develop AIDS had the same drug-use patterns as those who were HIV-positive but had not developed AIDS during a comparable period of time. The study also found that only HIV-infected people developed AIDS.

According to the researchers, these papers mark the first time that anyone has examined the correlation between drug use, HIV infection and AIDS in a controlled clinical setting with the specific intent of shooting down Duesberg’s theories.

The reports lay bare a bitter fight between Duesberg, who says he has lost his government research grant as a result of his views, and public health experts, who are trying to stem the tide of AIDS by spreading the message that it can be curbed through safe-sex practices.

“Peter Duesberg, as you know, is a prominent person, a member of the National Academy of Sciences, and he continues to go around and preach what we think is not only erroneous but very misleading and, in a sense, dangerous position,” said Warren Winkelstein, who teaches at the UC Berkeley School of Public Health and is one of the authors of the Nature article. “Many investigators don’t engage in dialogue with Peter because it is not very rewarding, but we felt we had a responsibility to do so.”

Duesberg, however, said he does not accept the findings.

“It’s a shot from the hip, in my opinion,” he said. “I think it’s the wrong conclusion. . . . They have spent millions of dollars and eight years of research on the wrong hypothesis (that HIV causes AIDS).”

Duesberg gained fame as the first virologist to map the genetic structure of retroviruses--the category of viruses that includes HIV. He argues that AIDS stems from widespread drug abuse, particularly intravenous drug use, that wears away the immune system, leaving the body vulnerable to fatal illnesses such as pneumonia and lymphoma.

More recently, he has also begun to argue that AZT, a drug widely prescribed to those who are HIV-positive, actually causes AIDS by destroying bone marrow, the foundation of the immune system.

“I think that’s hardly worthy of a response,” said Martin Ascher, an immunologist at the California Department of Health Services who was the lead researcher in the San Francisco study. “By that logic, antibiotics cause infection and chemotherapy agents cause cancer.”

The AZT hypothesis was not tested by either the researchers in San Francisco or in Vancouver. Both sets of scientists drew their data from long-running “cohort” studies, in which a large group of people is studied over a period of years. The San Francisco study began in 1984; the Vancouver cohort was formed in 1982.

In the San Francisco study, researchers compared heavy use of marijuana, nitrite inhalants, cocaine and amphetamines among 215 heterosexual men and 812 homosexual and bisexual men. The researchers found that except for the inhalants, which were used heavily only in the homosexual study population, the percentage of study subjects reporting heavy drug use was about the same in each group.

The study subjects were asked about their drug use for the two-year period before the study began, and during the following eight years were again questioned at six-month intervals. During that time, 215 of the homosexual and bisexual men developed AIDS, but none of the heterosexuals did.

Had drug use been a factor, the researchers concluded, the heterosexual men would have developed the disease at the same rate as the homosexuals.

The Vancouver study has been following 715 homosexual men. According to the lead researcher, Martin Schechter of the University of British Columbia, 365 are currently infected with HIV and 350 are not. Among the HIV-infected men, Schechter said, there have been 136 cases of AIDS, compared to none in the uninfected men.

“Drug use was one of the factors we looked at, which did not have any effect on this analysis,” he said. “Our essential conclusion was that AIDS illnesses don’t occur in people who were not infected with HIV.”