Regenerative medicine and stem cell therapy

The British Small Animal Veterinary Association (BSAVA) recognises that regenerative medicine and stem cell therapy have the potential to provide new treatment strategies for a wide range of diseases and conditions  for which there are currently no or limited therapeutic options.  Although these treatments have the potential to improve the health and welfare of animals it is important that the benefits and risks are fully evaluated before being made commercially available.

The BSAVA supports and encourages scientific research into the development of regenerative therapies including animal stem cell use.  The BSAVA recognises the need for well-designed, ethically approved, clinical trials in order to establish a knowledge base on the safety and efficacy of stem cell therapies.

The BSAVA recommends that veterinary surgeons considering the use of stem cell therapies should take note of the ethical and evidential issues in recommending any novel treatment.  The veterinary surgeon should make clear to the owner the nature of the procedure, the evidence that is and is not available regarding each of the treatment options and ensure that the owner understands that the procedure is “novel”, as part of the process of obtaining informed consent.

The BSAVA recommends that consideration is given to appropriate regulation of these therapies in order to protect animal welfare.

Regenerative medicine is the term used to refer to methods that aim to replace or regenerate cells, tissues or organs in order to restore or establish normal function. This can include a range of techniques including cell therapies, tissue engineering and gene therapy.

Stem cells are cells that have the ability to continuously divide to generate exact copies of themselves in a process called self-renewal and the ability to change into specialised cells in a process called differentiation.Differentiation is the process by which an unspecialised cell acquires the features of a specialised cell such as a heart, liver, or muscle cell.  This process is controlled by the interaction of a cell’s genes with the physical and chemical conditions outside the cell, usually through signalling pathways involving proteins embedded in the cell surface.

There are several different types of stem cells which are characterised by their origin and potential to differentiate.

Embryonic stem cells are undifferentiated cells derived from a pre-implantation embryo which have the potential to differentiate into many different types of cells, i.e. they are pluripotent.

Tissue stem cells (sometimes referred to as adult or somatic stem cells) can give rise to at least one specialised (differentiated) cell-type.

• Unipotent stem cells can only make one type of specialised cell
• Multipotent stem cells have the ability to develop into a limited number of specialised cell types
• Pluripotent stem cells are cells that are capable of differentiating into a wide range of tissues.  While tissue stem cells are not naturally pluripotent, it is now possible to induce this feature by artificially activating specific genes.  These are called induced pluripotent stem cells (iPS).

A stem cell therapy is a treatment that uses stem cells, or cells that come from stem cells, to replace or to repair a patient’s cells or tissues that are damaged.  The stem cells might be put into the blood, or transplanted into the damaged tissue directly, or even recruited from the patient’s own tissues for self-repair.

Autologous stem cells are collected from the same animal in which they are used as treatment.

Allogeneic stem cells are those where the donor and recipient are different individuals from the same species.

There is currently a great deal of research taking place into stem cell therapies in both human and veterinary medicine.  However, currently the only approved medical use of stem cells in the United Kingdom is bone marrow transplantation (Centre for Regenerative Medicine).  Other stem cell treatments being used in human medicine, including emergency skin grafts using skin (epidermal) stem cells and repairing the cornea of the eye using limbal stem cells, are still undergoing clinical trials.

• Novel procedures
• Complementary and alternative therapies 

The House of Lords Science and Technology Committee – First Report on Regenerative medicine
The Medical research Council’s Centre for Regenerative medicine
EuroStemCell (European consortium for stem cell research)

BSAVA Scientific Committee October 2016
BSAVA Council November 2016