Nov. 25, 2009 — Researchers may have found a new way to delay, or perhapsprevent, type 1 diabetes.
Type 1 diabetes usually begins early inlife, when the T-lymphocyte arm of the immune system attacks insulin-making beta cells inthe pancreas. Researchers hoping toslow or stop this process have targeted T lymphocytes or T cells.
But recent research suggests that B lymphocytes play a role in T-lymphocyteimmunity. 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 diabetesexperts from 12 U.S. and Canadian diabetes centers.
Pescovitz and colleagues report data from 78 newly diagnosed type 1 diabetespatients who completed a double-blind, randomized, placebo-controlled trial ofthe arthritis and cancer drug Rituxan. Rituxan, aman-made antibody, attacks B cells via the CD-20 molecule on the surface of thecells.
Patients got a single four-infusion course of Rituxan and then were followedclosely for a year. Over the course of the year, patients who received the drughad slower loss of insulin-producing cells as measured by C peptide (duringinsulin production in the pancreas, proinsulin molecules are split into insulinand 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 originalvalues.
But the study does show that a treatment targeting B cells can preservebeta-cell function in early type 1 diabetes.
“It is unlikely that treatment with [Rituxan] as administered in this studywould be optimal,” Pescovitz and colleagues note. “Given our results, webelieve 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 JuvenileDiabetes Research Foundation, and the American Diabetes Association. Pescovitzand colleagues report their findings in the Nov. 26 issue of the New EnglandJournal of Medicine.