MS attacks might be thwarted by blocking adhesion molecules.

Adhesion Molecules

Before destructive immune cells can damage the myelin that protects nerve fibers, they must enter the central nervous system, where they are not normally found. In fact, the central nervous system is protected from unwanted visitors from the bloodstream by a specialized cell layer called the blood-brain-barrier.

An innovative approach to stopping MS involves blocking adhesion molecules found on the surfaces of immune cells and on cells that form blood vessel walls. These hook-like adhesion molecules stick immune cells to vessel walls - an early step in the trip immune cells take through the barrier and into the brain and spinal cord.

In laboratory studies, animals with EAE (experimental allergic encephalomyelitis, a disease that causes MS-like symptoms) were given specially engineered antibodies designed to make the adhesion molecules unsticky. The treated lab animals had fewer immune cells in their central nervous systems, less myelin damage, and fewer symptoms compared to a control group not given the antibody.

Icos Pharmaceuticals has initiated safety studies of similar antibodies in people with MS, and Athena Neurosciences is preparing to do the same. The National MS Society has supported research at Stanford University to learn more about adhesion molecules and antibodies that can block them.

4-AP Studies Continue

4-AP (4-aminopyridine) has proved problematic in clinical studies. The drug may help nerve impulses move more easily through nerve fibers that have inflamed or damaged myelin covering. It has been studied in clinical trials both here and in Europe.

However, in doses high enough to produce modest improvements in walking, fatigue levels, and vision, several studies reveal side effects such as dizziness and burning or tingling sensations that limit its usefulness. With long-term use, a small number of more serious side effects have occurred, including seizures. More studies are in progress.