December 22, 2008

Healthy may have possible autoimmune cells

Potential autoimmunity-inducing cells have been found in healthy humans as well patients with autoimmune diseases such as lupus, U.S. researchers report.

Whether these cells are precursors to the self-attacking cells prevalent in lupus and rheumatoid arthritis remains unknown, researchers lead by J. Andrew Duty at the Oklahoma Medical Research Foundation reported in a news release.

As antibody-producing B cells develop in the bone marrow, the body tests them to determine whether they confuse the body's own tissue for that of intruders. If so, the receptors are either rearranged to make new, non-autoreactive versions or killed while still in the marrow, researchers said. A few cells, however, slip into the body as mature B cells with a propensity for self-attack.

In their study, Duty and his researcher team pin-pointed a similar population of immunity-lacking B cells in the blood of healthy adults, accounting for 2.5 percent of B cells in the circulating blood. The potential to produce these trouble-making antibodies lead the authors to suspect that these cells may contain the precursors for the self-attacking B cells in patients with autoimmune diseases.

Their findings were reported in the latest edition of the Journal of Experimental Medicine.