The New York Times - April 22, 1984
Lawrence K. Altman

"I believe we have the cause of AIDS, and it is an exciting discovery," Dr. Mason, who is a virologist, said in an interview here. "The public needs to know that this is a breakthrough and that it is significant."

The French virus is called LAV, for lymphadenopathy-associated virus. It is a member of the retrovirus family, which over the past year has been the leading candidate as the cause of AIDS.

New Findings in Paris

Dr. Mason said he based his opinion on findings made in recent weeks by the researchers who discovered the virus at the Pasteur Institute in Paris last year. Dr. Mason said his opinion was also based on additional findings made by scientists at the disease centers here and at the National Institutes of Health in Bethesda, Md.

He stressed, however, the need for additional research to confirm the findings.

"We cannot know for sure now that the LAV virus is the agent that causes AIDS, but the pattern it follows in the human body makes us believe it is," Dr. Mason said.

AIDS, which was first recognized in 1981, is a fatal disorder that destroys the body's immune system. According to the Centers for Disease Control, 4,087 cases were reported in the United States as of Monday, and 1,758 patients have died.

More than two-thirds of the victims have been homosexual men; most of the others have been users of intravenous drugs or hemophiliacs who require frequent blood transfusions. A number of cases have been reported among people of Haitian descent who do not seem to fall into those categories, although there is controversy among medical authorities over their inclusion among the "risk groups."

Dr. Mason predicted that in time the new findings would lead to development of a diagnostic test for AIDS as well as a test to help in prevention. For one thing, he said a test might be developed to screen out AIDS-contaminated blood before it was transfused to patients.

Tests could also open up the possibility of developing a vaccine against AIDS.

Dr. Mason expressed confidence that methods would quickly be found to grow large amounts of the virus in cells in the laboratory.

Dr. Mason said he did not foresee any insurmountable obstacles to development of a vaccine, although the process could take many years. He said that when the time came for testing a vaccine, he doubted it would be difficult to recruit human volunteers.

Meanwhile, information derived from a diagnostic test might help researchers determine if there were other means of temporarily correcting the abnormalities of the immune system resulting from the syndrome.

Possible Treatment Mentioned

One possible treatment that is being discussed only in theory was mentioned by Dr. Mason. It would be to transfuse AIDS patients with gamma globulin from people who had developed some immunity to the disorder and who had not developed a full- blown case. Gamma globulin is the portion of the blood that contains the antibodies that humans normally form to protect against infections.

One reason for believing that the virus is the cause of AIDS, Dr. Mason said, is that tests first done in France have shown that the LAV attacks the same white blood cells, called OKT4, or helper T-cells, that are destroyed by the disease.

The centers' director said that the inability thus far to infect animals with the LAV virus had enormously increased the difficulty of proving the causal relationship between the virus and AIDS.

If the LAV virus is not confirmed or validated as the cause of the disease in months to come, Dr. Mason said he recognized that the Government agency might have a credibility problem.

Nevertheless, Dr. Mason said he was speaking out because of the urgency of the AIDS epidemic.

"We have to move forward on the assumption that this virus is the cause in order to speed up trials of possible new therapies for the patients who are dying from AIDS," Dr. Mason said.

Federal health officials have scheduled a news conference in Washington for 1 P.M. Monday, presumably to discuss findings made by an AIDS researcher, Dr. Robert Gallo, and his colleagues at the National Cancer Institute concerning a retrovirus they have reportedly called HTLV-3, for human T-cell lymphotropic virus. It is believed to be different from another retrovirus called HTLV-1 that had been a focus of research into AIDS.

A report by Dr. Gallo's group is scheduled to be published soon in the journal Science.

Dr. Gallo could not be reached for comment.

Dr. Mason and other scientists familiar with the research said that they presumed HTLV-3, LAV and a third virus known as IDAV were different names given to the same virus. But tests have not yet been made to determine whether the viruses are the same or not.

"Logic would lead you to believe that we are dealing with one agent with perhaps some closely related variants," Dr. Mason said.

Similar Viruses Isolated

Isolates of viruses similar to the LAV have been made in several laboratories, and dozens of papers from these research groups are being written or have been submitted to medical journals.

One has been published by the team from the Pasteur Institute, the Claude Bernard Hospital and La Pitie- Salpetriere that discovered the LAV virus.

In the April 7 issue of Lancet, a medical journal published in London, an 11-member French research team headed by Dr. E. Vilmer said that it had found a retrovirus that it called IDAV for immunodeficiency-associated virus in the blood of two brothers with hemophilia. One of the brothers had developed AIDS.

Dr. Luc Montagnier, a member of the French team, said in an interview that although his colleagues could not distinguish IDAV from LAV they had given it a new name because they could not be absolutely certain at this time that the two were the same. Dr. Montagnier said that the viruses could not be distinguished by electron microscope and immunological tests but that molecular biological detection tests still needed to be done.

Researchers Collaborating

Researchers at the Centers for Disease Control have been collaborating with the French scientists and with Dr. Gallo in the AIDS research.

A C.D.C. researcher said that they had sent samples from AIDS patients to Dr. Gallo's laboratory.

On previous occasions when Dr. Gallo's team published in conjunction with C.D.C researchers, the researchers at the diseases centers said they had received copies of the papers in advance.

In answer to a question, however, Dr. Mason said that researchers at the centers had not yet received a copy of the paper Dr. Gallo's team is publishing in Science.

Dr. Gallo is recognized by many as the world leader in retrovirus research. Dr. Mason praised Dr. Gallo's previous contributions to the field as well as his work on the AIDS problem.

One of Dr. Gallo's papers concerning HTLV-1 and AIDS appeared in the issue of Science in which the French researchers published their results of the LAV virus last May.

Dr. Mason, who became director of the Centers for Disease Control last December said he did not know why it had taken so long for the significance of the French work to be recongnized.

"There was so little excitement in the scientific community when the French came up with their announcement last May," Dr. Mason said.

French Researchers Visit U.S.

It was not until last winter, after members of the French team visited researchers in this country and presented findings at a meeting in Utah, that American scientists, many of whom had already been working with the LAV virus, became enthusiastic about its role in AIDS, Dr. Mason said.

If a diagnostic test is developed, it would allow researchers to begin to try to answer the myriad questions that have arisen about AIDS. Among the unanswered questions are:

- What are the first symptoms of AIDS? Until now, for many AIDS patients the first symptoms are infections caused by micro-organisms that usually do not have the opportunity to infect people whose immune systems are working normally. Doctors believe that the AIDS infection begins long before these type of opportunistic infections develop.

- What exactly is AIDS? "We call it AIDS but we haven't fully described the disease yet," Dr. Mason said. A diagnostic test might help clarify the definition.

- How long does it take from the time of exposure to the onset of symptoms? Doctors believe the incubation period can be five or more years. But they have no precise data about how many cases take that long and how many occur with a shorter incubation period.

- Is there an anti-viral drug that has not been tested on humans that might be effective against AIDS? Samples of the causative virus would allow laboratory tests of a type not now possible.

- How many people have been infected by AIDS? The diagnosis of AIDS is now made on the basis of a working definition established by the Centers for Disease Control. Such definitions are standard epidemiological tools in investigations of diseases of unknown origin.

Some AIDS experts have expressed strong suspicions that the disease affects tens of thousands of people who do not meet the CDC definition of AIDS but who cannot be diagnosed for lack of a diagnostic test.

Researchers have found that AIDS affects about as many women as men in Zaire and Haiti whereas in the United States AIDS primarily affects homosexual men. A diagnostic test, Dr. Mason said, "would help us tremendously to answer the question of why there is such a difference in sex distribution."

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