AIDS Virus May Infect the Brain, Medics Say
A growing body of evidence indicates that the virus that causes AIDS reproduces itself in the brain, as well as in blood cells, and that it appears able either to rest there in a dormant state for long periods of time or cause chronic neurological disease.
Physicians have suspected that mental disorientation, depression and impaired memory and judgment seen in some patients with acquired immune deficiency syndrome are due to the direct effects of the virus on brain cells, but the scientific documentation for this theory has been scanty.
Two reports published today in the New England Journal of Medicine by doctors from half a dozen medical centers, including Wadsworth Veterans Administration Hospital in Los Angeles and the National Institutes of Health, suggest that the virus associated with AIDS is responsible for some of the neurological conditions that doctors are otherwise unable to explain.
‘Definitely There’
“We feel very strongly about this--no ifs, ands or buts. The virus definitely is there (in the brain and spinal canal),” Dr. Lionel Resnick of Miami’s Mt. Sinai Medical Center and principal author of one of the reports said in a telephone interview.
Both Resnick’s paper and the other by Dr. David D. Ho of Massachusetts General Hospital in Boston offer evidence that HTLV-III, the virus associated with AIDS, is directly responsible for some of the neurological conditions that are seen in many AIDS patients. These illnesses include chronic meningitis, dementia and so-called AIDS encephalopathy.
Resnick’s paper also indicates that HTLV-III reproduces itself inside brain cells where, in some cases, it causes neurological problems in patients who have no signs of a deficiency of their immune system, a chief characteristic of people infected by the virus associated with AIDS.
In an editorial accompanying the articles, Dr. Paul H. Black of Boston University School of Medicine said the studies show that HTLV-III must now be counted among the viruses that can exist in the brain.
Other Viruses
Other viruses that are known to infect the brain, where they remain either dormant or cause disease, include the herpes simplex viruses and the measles virus. Another type of organism, called a prion, has been suspected as the cause of several rare lethal brain conditions known as Creutzfeld-Jakob disease and kuru.
Black said evidence provided by Resnick and other researchers that the HTLV-III infection in the brain is a persistent one indicates that it will be difficult to bring adequate concentrations of antiviral drugs into the brain to eliminate the virus. The difficulty is increased, he said, by the existence of a natural barrier, called the blood-brain barrier, that is intended to keep foreign substances--which would include some drugs--from entering the brain from the bloodstream.
“Once we learn what the virus is doing in the brain, we will be able to apply the findings to other neurological diseases,” Resnick said in the interview. “AIDS research will open the door also for cancer and for understanding how the immune system works.”
