New Target for Sjögren Syndrome
Experimental Vaccine Treats Dryness Disorder 
By: Jennifer Warner

WebMD Medical News Reviewed By Michael Smith, MD

Oct. 4, 2002 -- The discovery of a protein that triggers Sjögren syndrome in mice is now providing valuable clues into this immune disorder. Researchers say they've already tested a vaccine that, at least in mice, stops the body's attack on its moisture-producing glands.

The disease, known as Sjögren syndrome, most frequently strikes middle-aged or postmenopausal women and affects up to 1% of the population. It often occurs along with other diseases that affect body tissues, such as rheumatoid arthritis, lupus, and scleroderma.

The syndrome causes the body's immune system to destroy glands in the eyes, mouth, and other parts of the body that produce much-needed lubrication and moisture. Symptoms include dry eyes and mouth, fatigue, and joint pain, and there are currently no effective treatments.

In a study published in the Oct. 5 issue of the journal The Lancet, researchers say they've identified a protein, known as ICA69, that plays a vital role in the development of Sjögren syndrome. By removing the gene that produces this protein in mice, researchers were able to prevent the disease from developing in the tear glands and substantially limit the disease in the salivary glands.

In addition, the researchers say a prototype vaccine was able to stop the disease from progressing in mice that already had Sjögren syndrome.

"Our vaccine was able to stop Sjögren syndrome even after the disease had fully developed, an unusual finding, since in other autoimmune disorders it is impossible so far to stop and reverse the disease process once it is fully established," says researcher Michael Dosch, MD, senior scientist at The Hospital for Sick Children in Toronto, in a news release.

"This finding is also exciting because it opens the door to further knowledge about treating selective organ autoimmune diseases, including the possibility of vaccines," says Dosch.

Researchers say they are planning a study involving at least 100 Sjögren patients to learn more about the link between this protein and the immune system in preparation for potential clinical trials of the vaccine.

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