The symptoms of MS are not specific but may affect many different abilities, including difficulty with balance and walking, trouble with coordination, numbness or ‘pins and needles,' blurred vision, urinary and sexual dysfunction, speech impairment and cognitive or emotional problems.

MS is usually treated with drugs that modulate the immune response, depending on the stage of the illness and its prognosis. These drugs often have the effect of slowing the disease or of preventing (or delaying) the exacerbation of symptoms. Scientists believe the disease returns because therapies have failed to change the immune response that gives rise to the CNS inflammation or to remove the immune ‘memory' that has learned to attack the myelin.

Importance of early treatment

Although immunoablative therapy appears to have arrested inflammation and prevented new lesions in the clinical trials mentioned above, it does not appear to have stemmed the progressive neurodegenerative aspects of MS that were already underway.

Scientists are concluding from these and other studies that early intervention (before significant disability) is critical in treating MS. Inflammation at an early stage of the disease leads to the eventual loss of axons and neurons. It is believed that at some point the disease undergoes a transition from primarily an inflammatory disease to a more progressive neurodegenerative disease.

Multiple sclerosis, as a multi-factorial, autoimmune disease affecting the nervous system, has prompted research in several different specialties: cell biology, genetics, immunology and neuroscience. These streams of research are all in their own way trying to explain what triggers the disease, the wide variety of symptoms and the baffling course of progression. While the aim is ultimately to help those who suffer with the disease, the research into MS both borrows from, and contributes to, our understanding of the mechanisms involved in all autoimmune diseases.

Stem cell research into MS is developing new imaging technology and laboratory techniques that will help researchers understand what is really going on in the brain and in the genes that control the immune system. The lessons learned in treating MS might also be applicable in understanding and developing new treatments for other autoimmune diseases, such as rheumatoid arthritis, Crohn’s disease and lupus.

Broadly speaking, MS research is concentrating on two questions:  how can the disease progression be arrested?  Can the nervous system be repaired to restore neurological functioning once it has been lost? Stem cells are hoping to answer both of these questions.

Halting disease progression

Stem cells have been used for years to treat leukemia and other blood cancers through transplantation of bone marrow. Scientists have are considering the possibility that the same process, known as hematopoietic stem cell transplantation (HSCT), can be adapted to arrest the progression of MS in patients who have an especially aggressive disease diagnosed early on and a poor prognosis.

There are two kinds of stem cell transplantation: autologous transplantation (a graft of the patient's own stem cells from the blood or bone marrow that have been purified of immune cells) and allogeneic transplantation (stem cells from a donor's bone marrow or bloodstream). In theory, autologous HSCT would benefit patients with an autoimmune disease caused by a strong environmental trigger, whereas allogeneic transplantation might be more suitable for treating autoimmune diseases with a strong genetic basis.

Brain repair and tissue regeneration

In order to address the question of whether myelin that has already been destroyed by MS can be repaired, cell biologists are trying to determine how and why immune cells create and perpetuate the autoimmune response and by what mechanism the demyelination occurs. MS not only destroys myelin but it damages or kills the cells that make myelin (oligodentrocytes) and nerve cells. They are hoping to crack the cell signaling codes and interrupt the pathways that orchestrate destruction of the myelin sheath. This will help them understand under what conditions remyelination might occur, and the possible role of drug therapy, gene therapy or stem cell therapy.

Whether the transplanted stem cells are responsible for the functional improvement seen in some MS patients who undergo HSCT, or whether stopping inflammation may allow the brain to repair itself is unclear, but understanding these mechanisms might lead to treatments to enhance and encourage remyelination. This is the focus of research on mesenchymal stem cells. These are stem cells derived from the bone marrow that have immune-suppressing and regenerative properties and in theory may be capable of repairing the brain damaged by MS.

Stem cell research for MS is progressing worldwide. Some researchers are concentrating on the autoimmune response, others are decoding the signals that prompt the brain to repair itself by forming new myelin when the original myelin has been destroyed. While the ultimate objective is to find a cure, current stem cell research is providing vital clues and making it possible in the foreseeable future to induce and prolong remission, or even alter the course of the disease.

Our thanks go to the Stem Cell Network in Canada for their work on this information