The autoimmune disease multiple sclerosis affects around 400,000 Americans. It’s caused by the immune system erroneously responding to myelin, a fatty substance that coats the nerves to protect them. This myelin sheath helps nerve impulses travel along the neural pathways faster and more efficiently. When the immune system damages this protective layer, this results in functional deficiencies as impulses traveling through the unprotected nerve fibers are slowed down and interfered with as they pass. This results in several temporary but recurring problems including muscle weakness, fatigue, lack of coordination, and unsteadiness in walking. These symptoms come and go in irregular cycles.
This happens when a protein called fibrinogen gets into the brain and triggers the immune response against the myelin sheath. Fibrinogen plays an important role in coagulation of the blood, but is not normally found in the human brain. That, in fact, may be the reason that when fibrinogen crosses the blood-brain barrier, it activates the immune system. However, scientists are not entirely sure how or why the protein gets in the brain in the first place. Recent research showed some evidence that a food-borne bacterium called Clostridium perfringens may be partly responsible. Some strains of the bacterium produce a substance called epsilon toxin, which allows the protein through in people with a genetic predisposition to the condition.
Multiple sclerosis is currently thought of as untreatable, however this and other research provides promising avenues. A vaccine against epsilon toxin, or an antidote, could help prevent multiple sclerosis from developing in the first place. Researchers have found ways to alter fibrinogen so it is unnoticed in the brain. Other researchers have proposed using nanoparticles to hide myelin cells from their attackers.
One recent study found that statin drugs can help substantially slow the progression of the disease. Statin drugs are ordinarily given to people with high cholesterol to bring it back down into the normal range. They also have anti-inflammatory effects. In the study, a drug of this kind called simvastatin was able to fight multiple sclerosis symptoms. In later stages of the disease, the brain itself starts to sustain damage. Patients in the study who received simvastatin had a little more than half the amount of damage to the brain.