RESEARCHERS in the USA are recruiting for a trial that will look at the safety and tolerability of a procedure that attempts to treat multiple sclerosis damage in the central nervous system with an individual’s own stem cells.

Previous therapies have involved using stem cells from bone marrow to repopulate an individual’s immune system that has previously been largely wiped out with chemotherapy drugs.

This new study will test the ability of mesenchymal stem cells isolated from the individual’s bone marrow to both regulate the immune system and to help repair damaged tissue.

The study is based in Cleveland, Ohio and will recruit 24 people with relapsing remitting MS.

Pam Macfarlane, chief executive of the MS Trust, said:

“While this is a USA trial and not open to people with MS in the UK it will provide data on the potential of transplanted mesenchymal cells.

“The importance of stringent, controlled trials to establish efficacy and safety cannot be underestimated and it is very encouraging to see that this study is commencing in the USA where there have been reservations about stem cell research.”

What are stem cells?

Stem cells are different from all other kinds of cells in the body:

They are unspecialised – this means they are not modified to have a specific function in the body;
They are able to divide and renew themselves for long periods of time – this is known as proliferation;
Under specific conditions they have the potential to develop into cells with special functions – this is known as differentiation. For example, stem cells have the potential to differentiate into the beating muscle cells of the heart, cells that produce insulin in the pancreas or nerve cells in the brain.
There are two main types of stem cells – embryonic stem cells and adult stem cells.

Embryonic stem cells
As the name suggests, embryonic stem cells are found in the developing embryo. These cells are capable of developing into all the cell types that make up the tissues and organs of the human body, such as the heart, skin and brain.

Adult stem cells
Stem cells are found in much smaller numbers in adults than they are in embryos. Adult stem cells are found in some adult tissues and organs, including the bone marrow, the blood and the brain. The role of adult stem cells is to maintain and repair cells that are lost through general ‘wear and tear’, injury or disease.

Adult stem cells are more limited in the types of cells they can differentiate into; they typically generate into the types of cell in the tissue where they are found. Some examples are:

Haematopoietic (blood-forming) stem cells – found in the bone marrow, the blood and also the umbilical cord of newborn babies. They differentiate into all of the different types of blood cells including red blood cells, white blood cells and platelets.
Stromal stem cells – found in the bone marrow. They differentiate into tissues including bone, cartilage and fat cells.
Neural stem cells – found in the brain. Neural stem cells can give rise to the major cell types in the brain, includingneurons (nerve cells) andoligodendrocytes (myelin-forming cells).