A small number of multiple sclerosis patients remained stable after a year of injections with an experimental vaccine, a finding that could lead to a way to protect an MS patient’s immune system from attacking itself.
The study, being published in today’s Nature Medicine, suggests that it is possible to trigger an immune response targeted specifically against the immune cells that mistakenly attack myelin, the protective coating around nerve cells that is destroyed by the disease.
“We are very excited,” said Patricia O’Looney, director of research and training at the National Multiple Sclerosis Society. “Now, we need larger studies to confirm the vaccine’s effectiveness.”
Arthur Vandenbark, a scientist at the Veterans Affairs Medical Center in Portland, developed the selective vaccine and has been testing it in animals and, more recently, humans. It is made from a molecule found in white blood cells that seems to attack the myelin sheath around nerve cells.
The recent study included 23 MS patients in moderate to severe stages of the disorder. They were all still walking, but many needed wheelchairs for a good part of the day, Vandenbark said.
Members of the group randomly received one of two forms of the vaccine, or a placebo. The second vaccine was developed by changing one amino acid, which scientists hoped could trigger an anti-autoimmune response, causing the body to produce more good T-cells, a type of blood cell. Weekly injections were given for four weeks, and then once a month for the remainder of the year. Five of nine patients responded to the second vaccine, compared with one of eight who received the first vaccine. None of the patients who took placebos responded.
“It was quite striking,” said Vandenbark. He added that the vaccine works by turning on good immune cells, which work against the immune cells that wage a war against myelin. Those patients who responded had more of the good immune cells, the scientist said.
About 300,000 Americans suffer from MS and there is strong evidence that it is an autoimmune disorder. Specific T-cells in the immune system mistakenly attack the protective sheath around the nerve cells and spinal cord.
This destruction causes painful symptoms, which can include unusual tiredness, loss of balance and muscle coordination, slurred speech, tremors and difficulty walking.