The Little Antibody That Could

By Christine Gorman

There are plenty of reasons not to tell you about an experimental new treatment for Type 1 diabetes, a particularly devastating form of diabetes in which the body's immune system attacks the insulin-producing cells of the pancreas. Experimental therapies often fail, and even when the treatments work, widespread availability is usually years away. But a study in last week's New England Journal of Medicine offers such intriguing insights into the future of treatment--not just for Type 1 diabetes but also for a number of autoimmune disorders--that it's hard to resist. Just keep in mind that these are preliminary results.

First a little background: no one knows why the immune system goes haywire and starts triggering autoimmune disorders, but at least one culprit is a particular kind of immune cell called a T cell. In Type 1 diabetes (which used to be known as juvenile-onset diabetes), T cells destroy the cells of the pancreas. In multiple sclerosis, they cross the biomolecular barrier that protects the brain and attack the outer covering of nerve cells. If you could deactivate the right T cells, you might be able to slow down the degenerative process--and maybe halt it altogether.

That's exactly what seems to have happened in the NEJM study. Researchers cloned antibodies known to target T cells and for two weeks gave them to 12 patients who had just had Type 1 diabetes diagnosed. Another dozen patients received standard medical care. A year later, doctors examined their subjects and discovered that the disease had been halted in nine of the patients who received the antibodies. They still had to take insulin because the damage that had already occurred could not be undone. Most of the control group, by contrast, seemed to have got worse and had to take more insulin.

The most exciting thing about these results, says Jeffrey Bluestone, an immunology expert at the University of California, San Francisco, who developed the treatment, is that it shows "you can fundamentally change the immune system without the need for long-term therapy." In other words, the immune system can be retrained.

There are side effects. Some patients developed fevers, rashes and anemia. There's also a theoretical possibility, says Dr. Kevan Herold, principal investigator at Columbia University's medical school, that the treatment will increase the risk of developing cancer. But for now, researchers are sufficiently encouraged to launch another trial that will test whether repeating the two-week treatments every six or 12 months makes a difference. There are also plans to try the antibody treatment on a kind of autoimmune arthritis that develops in people with psoriasis. (The treatment is not expected to work on Type 2 diabetes, which has different causes.)

Doctors still have a lot to learn in their efforts to restore the wayward defenses of patients with autoimmune disorders. Last week's results suggest, however, that they are well on their way.

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