Nov. 25, 2009 -- Researchers may have found a new way to delay, or perhaps prevent, type 1 diabetes.
Type 1 diabetes usually begins early in life, when the T-lymphocyte arm of the immune system attacks insulin-making beta cells in the pancreas. Researchers hoping to slow or stop this process have targeted T lymphocytes or T cells.
But recent research suggests that B lymphocytes play a role in T-lymphocyte immunity. In non-obese mice with diabetes, depleting B cells inhibits the disease. Can it work in humans?
Yes, find Indiana University's Mark D. Pescovitz, MD and a team of diabetes experts from 12 U.S. and Canadian diabetes centers.
Pescovitz and colleagues report data from 78 newly diagnosed type 1 diabetes patients who completed a double-blind, randomized, placebo-controlled trial of the arthritis and cancer drug Rituxan. Rituxan, a man-made antibody, attacks B cells via the CD-20 molecule on the surface of the cells.
Patients got a single four-infusion course of Rituxan and then were followed closely for a year. Over the course of the year, patients who received the drug had slower loss of insulin-producing cells as measured by C peptide (during insulin production in the pancreas, proinsulin molecules are split into insulin and C-peptide).
Unfortunately, a single course of Rituxan wasn't enough to stop diabetes. After a year, B cells in treated patients increased to 69% of their original values.
But the study does show that a treatment targeting B cells can preserve beta-cell function in early type 1 diabetes.
"It is unlikely that treatment with [Rituxan] as administered in this study would be optimal," Pescovitz and colleagues note. "Given our results, we believe that other anti-B-lymphocyte agents should be tested -- for example, anti-CD20 antibodies."
The study was funded by the National Institutes of Health, the Juvenile Diabetes Research Foundation, and the American Diabetes Association. Pescovitz and colleagues report their findings in the Nov. 26 issue of the New England Journal of Medicine.