MONDAY, Dec. 22 (HealthDay News) -- Healthy adults have potential autoimmune disease-causing cells, but these cells stay in an "off" state, a U.S. study shows.

Immune cells that attack the body cause autoimmune diseases such as lupus and rheumatoid arthritis (RA). Whether the switched-off cells in healthy adults are true precursors of the self-attacking immune cells and, if so, what prevents them from causing disease in certain people, isn't known, the researchers said.

J. Andrew Duty, of the Oklahoma Medical Research Foundation, and colleagues found that anergic (dormant) autoimmune disease-causing cells account for 2.5 percent of immune B-cells circulating in the blood of healthy adults.

These anergic cells don't appear to cause problems in healthy adults, but did produce self-reactive antibodies when exposed to a strong stimulus in lab experiments. This means these anergic cells may contain the precursors for the self-attacking B-cells in patients with autoimmune disease, the researchers said.

In previously healthy people, anergy may somehow break down and allow self-attacking B-cells to cause autoimmune disease.

The study was published in the Dec. 22 online issue of The Journal of Experimental Medicine.

More information

The U.S. National Women's Health Information Center has more about autoimmune diseases.

-- Robert Preidt

SOURCE: Rockefeller University Press, news release, Dec. 22, 2008

Last Updated: Dec. 22, 2008

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