A mysterious "virus-like agent" detected in AIDS patients has
been described in detail by a team of federal researchers, who
suggest that their findings may challenge prevailing wisdom on
what causes AIDS.
The researchers, at the Armed Forces Institute of Pathology and
the National Institutes of Health, said the agent may represent
a new infection striking people with damaged immune systems, or
may play "a more fundamental role as a co-factor" in triggering
"Our . . . data is too meager to make this distinction, but we
have unequivocally demonstrated the existence of a previously
unrecognized virus- like infectious agent in patients with
AIDS," they reported in the most recent issue of the American
Journal of Tropical Medicine and Hygiene.
Virologists and other AIDS researchers reacted with caution to
the findings, a follow-up to a brief, preliminary account by
the researchers in 1986. Scientists on Tuesday described the
more detailed results as provocative but not necessarily
They pointed out that the findings have yet to be confirmed by
other researchers--a crucial test of the credibility of a piece
of research. Some also cited what they described as limitations
in the federal researchers' methods and data.
All said they were withholding judgment on the significance of
"I think it's very interesting, I think it deserves more
attention," said Norbert Rapoza, a virologist and senior
scientist with the American Medical Assn. who has followed the
research. "I think it has to be looked at more closely."
Most leading researchers believe that AIDS is caused by the
human immunodeficiency virus, or HIV. The virus is thought to
gradually destroy a person's immune system, leaving the person
vulnerable to a range of infections that are eventually lethal.
Some AIDS activists and a few scientists challenge that
explanation, contending that AIDS may result from a combination
of forces or another virus. AIDS activists who hold that view
welcomed the newly published report on Tuesday, saying that it
supports their suspicions.
The federal researchers, headed by Shyh-Ching Lo of the Armed
Forces Institute, originally identified the new virus-like
infectious agent, called VLIA, in a single patient with
Kaposi's sarcoma, a form of cancer that affects some AIDS
Using a series of sophisticated laboratory techniques, the
scientists determined that the agent could infect cells.
Through analysis, they also concluded that it was distinct from
numerous other viruses, some of which have also been suspected
of being co-factors in causing AIDS.
They then examined DNA isolated from various organs in 10
people with AIDS; in seven, they found pieces of DNA apparently
similar to that of the virus- like agent. When they examined
DNA from people without AIDS, they found no such similarities.
"Our findings suggest that VLIA may represent a new
opportunistic infection in these severely (debilitated)
patients, or an agent which plays a more fundamental role as a
co-factor in the process associated with infection by HIV," the
Through intermediaries, Lo declined Tuesday to discuss his
The journal in which the report appeared this month is
published by the American Society of Tropical Medicine and
Hygiene. Virologists described the journal, mailed monthly to
3,600 specialists, as a respected forum for issues concerning
All reports must be reviewed and approved in advance by experts
in the field.
Virologists contacted Tuesday declined to speculate on the
significance of Lo's findings. Some also declined to be quoted
by name on the subject. They said the viral agent could prove
to be anything from a contributing cause of AIDS to nothing
more than a contaminant.
"I'm convinced that the agent does exist," said Rapoza, who
said he has followed Lo's work for 18 months. "I don't think
he's faking it. He has something; he has a virus. The question
is, where did it come from?"
Another prominent virologist said "it would be nice" to see
additional evidence--for example, confirmation by other
researchers, a good electron microscopic picture of the agent
and more proof that the agent is common in AIDS patients.
Meanwhile, in separate work, U.S. scientists announced Tuesday
that they have successfully modified the AIDS drug AZT in the
hope of making it more potent in counteracting HIV and reducing
its side-effects, such as anemia and bone marrow disorders.
Dr. Sudhir Gogu of Tulane University School of Medicine
announced the development of so-called DP-AZT at a meeting of
the Federation of American Societies for Experimental Biology
in New Orleans. He reported "promising results" in mice cells.
AZT, also known as retrovir or zidovudine, is the only approved
treatment for acquired immune deficiency syndrome on the U.S.
market. Although not a cure, the drug can prolong the lives of
AIDS victims by slowing the spread of infection from cell to
DE ACQUIRED IMMUNE DEFICIENCY SYNDROME; VIRUSES; MEDICAL RESEARCH;
INFECTIONS; HUMAN IMMUNO DEFICIENCY VIRUS; IMMUNE SYSTEM;