Pregnancy gives clues on treating multiple sclerosis

There is a ray of hope for people suffering from multiple sclerosis (MS). A recently published Canadian study shows that a pregnancy hormone could help repair nerve damage caused by the disease. This discovery could explain why pregnant women afflicted with MS tend to go into remission during their pregnancy.

MS most often occurs in young adults between the ages of 15 and 40, afflicting almost twice as many women as men. Between 13,000 and 18,000 Quebecois are suffering from this disease: that is one person out of 500 to one out of 1,000 depending on the region.

The exact cause of MS is still unknown at this point. While most scientists believe it is an autoimmune disease, it remains the most common disabling neurological disorder in young adults. For reasons still unknown, the immune system becomes dysfunctional and mistakenly attacks the myelin. Myelin is a fatty protein that protects nerve cells in the brain and spinal cord. The result is a blockage or alteration of the nervous influx. If we compare nerves to electrical wires, it is as if their protective plastic insulation (myelin) were eroding, thereby preventing the transmission of electricity (nervous influx). While MS symptoms vary according to the region of the body affected, sufferers often describe pain, weakness and/or loss of sensation. Other common symptoms are: fatigue, depression, memory changes, visual loss or double vision, unsteadiness and dizziness, weakness in a limb, shaking and loss of coordination, numbness and tingling, bladder, bowel and sexual problems.

While working with mice, scientists discovered that prolactin, a hormone produced during pregnancy, encourages the production of myelin, the fatty protein that acts as protective insulation for the nerve cells.

It is believed that during pregnancy, women’s immune systems stop attacking the myelin. Researchers observed that pregnant mice had twice as much myelin-producing cells called oligodendrocytes than virgin mice did, and continued generating them throughout their pregnancies. When researchers chemically destroyed the myelin surrounding nerve cells, they noticed that two weeks later, the pregnant mice had produced twice as much new myelin as the virgin mice. They then injected prolactin in virgin mice and observed a stabilisation of the disease: the myelin was also repaired. Not only could this discovery benefit people with MS, it could also help those with other forms of neurological disorders such as spinal cord injuries and stroke.

The treatments available to treat MS can stabilize the progression of the disease but are powerless in reversing the damage that has already occurred. Researchers are hoping to conduct clinical trials on humans within a few years.

We’ll keep you posted!