Hopes Raised in Fight Against Autoimmune Diseases

A new virus that appears to have similarities to the AIDS virus has been isolated from a patient with Sjogren’s syndrome, an uncommon ailment that causes dryness of the mouth and eyes, according to researchers at Tulane University School of Medicine in New Orleans.

The discovery, reported in today’s issue of the journal Science, is likely to spark renewed interest in the possibility that viruses play a role in causing a variety of uncommon autoimmune diseases, such as Sjogren’s, lupus erythematosus, and scleroderma.

“We are excited by the fact that we have a new human (virus),” said Robert F. Garry, associate professor of microbiology and immunology at Tulane and the leader of the research team.

But Garry cautioned in a telephone interview that “we have by no means established a cause-and-effect relationship between this virus and any autoimmune disease, including Sjogren’s disease. . . . We have a lot more work to do.”

In an autoimmune disease, the immune system, which controls the body’s defenses against germs, attacks the body itself. This attack can cause a variety of problems, such as arthritis and lung and kidney damage. Some researchers believe that viral infections may help to trigger the initial attack by the immune system, which then becomes self-sustaining.

Sjogren’s is more likely to occur in older individuals. In addition to dryness of the mouth and eyes, patients may also develop dryness of other organs, such as the lungs, joint inflammation, and heart, nerve and kidney problems. In advanced cases, death may occur from lung infections.

According to Garry, Sjogren’s patients have some common features with some patients infected with the human immunodeficiency virus, which causes AIDS, such as mouth and eye dryness. In both diseases, the dryness is related to the invasion of the saliva and tear glands by white blood cells.

In addition, patients with Sjogren’s and other autoimmune diseases, such as lupus, may have false-positive blood tests for infection with the AIDS virus.

The new virus, named human intracisternal A-type retroviral particle, was isolated from the salivary gland tissue of a Sjogren’s patient, according to the report.

Further tests in the laboratory established that the virus appears to be genetically related to the AIDS virus, Garry said.

Garry said his team is now trying to determine the genetic sequence of the virus and to develop diagnostic tests. Tests in monkeys are also planned to see if injections of the virus cause a Sjogren’s-like illness.