What are stem cells?

The human body is made of a variety of different types of cells that come together to perform various functions. In comparison, this is much like a city. In order for the city to function there are groups of people that perform different functions. Policeman keep the peace, cleaners keep the streets clean, waterworks engineers make sure that each household has water and healthcare professionals look after the sick. Different groups of cells in the body perform functions in much the same way. The kidneys filter and clean the blood, the muscles allow us to move our bodies and our skeleton has a support function and works in synergy with the muscles to allow us to move. As individuals can be trained into different professions the stem cells are a group of cells that have the potential to become any of the specialist cells in the body such as muscle, skin, bone, cartilage and blood.

How do stem cells work?

There are a number of ways that stem cells can work. In the laboratory, using very complex techniques, stem cells can become cells of different kinds of tissues such as bone cells or cartilage cells. They are placed on scaffolds and then place inside the diseased parts of the body in order to try and regenerate these areas. This technique has been performed for the past 20 years or so and scientists have met with varying degrees of success in trying to treat various diseases including arthritis. The results from the studies of these treatments greatly vary.

 More recently scientists have realised that stem cells do not necessarily turn into a variety of different cell types within the body but it maybe that they act as marshals in guiding the regenerative process within the tissues that are injured. The stem cells work by secreting a variety of chemicals that act in the injured tissues. These chemicals help in the clean up of the damaged tissues and then work to recruit the undamaged parts of the same tissue to start growing and replacing what has been lost.

What are Mesenchymal Stem Cells?

These are a subgroup of stem cells. They are only capable of making tissues of a certain type such as bone, cartilage, muscle and fat.

Here are some terms used in relation to stem cells and their meaning:

·- Self renewal: The ability of a stem cell to divide and produce copies of itself for an indefinite period of time.

·- Totipotent: A cell capable of forming an entire organism. When an egg is fertilised, it is called a zygote. This very special cell is totipotent. No other cell has this ability. All other stem cells can only form organs but not the whole animal.

·- Pluripotent: A cell able to form every type of organ and tissue in the body. An example of this cell is embryonic stem cells.

·- Multipotent: A cell able to form some but not all of the organs in a body. For example haematopoietic (blood) stem cells which are found in the bone marrow are only able to form the cells that make up our blood. Mesenchymal Stem Cells (MSCs) can for cells from the mesenchyme that include cartilage, bone, muscle and fat.

·- Differentiation: The process by which stem cells become specialized into specific organs to perform particular tasks. An example is when a MSC forms cartilage cells that go on to make cartilage which is seen in healthy joints.

What are misconceptions?

There are many misconceptions around the use of stem cells.  One of them is that embryos and foetuses are destroyed in order to provide stem cell treatments.  This clearly is not the case. The use of embryonic stem cells is illegal both in the United Kingdom and in Europe.

The stem cells that are used for treatments are adult stem cells which are harvested from the same individual that is being treated.

There is also a misconception that stem cells can cure absolutely everything.  This is certainly not the case as with any treatment modality there are failures.  In most orthopaedic treatments anywhere between 5% to 30% of individuals having a surgical procedure end up not having the full benefits that the surgical procedure intends.  It is the same with a variety of non-surgical treatments including physiotherapy, manual therapy, injections of various compounds including steroids and of course, stem cell treatments.