SCIENTISTS are recruiting patients with untreatable Crohn's disease to test whether a stem cell transplant can reboot their immune system and improve their response to drug treatments.

Participants are being sought from across the UK, including the Edinburgh area, for study which will use chemotherapy to wipe out their faulty immune systems before rebuilding it with stem cells harvested from their own body.

In theory, the new immune system will then no longer react adversely to the patient’s own gut to cause inflammation. It should also stop attacking drug compounds to remove them from the patients' guts before they have had a chance to work.

Crohn’s disease is a painful and chronic long-term condition that causes inflammation of the lining of the digestive system, resulting in symptoms including diarrhoea, abdominal cramps and extreme tiredness.

Scotland has one of the highest rates of Crohn’s disease in the world. In the past 25 years in Scotland, the number of children under-16 diagnosed with the condition has soared 750% - but the cause of the increase and the disease itself both remain unknown.

It is believed to be a type of autoimmune disorder where the immune system overreacts and attacks the body's healthy cells.

There is currently no cure and drug treatments to reduce inflammation have varying results. Surgery is often needed to remove the affected part of the bowel and, in extreme cases, some patients have to undergo a final operation to divert the bowel from the anus to an opening in the stomach, called a stoma, where stools are collected in a pouch.

Professor James Lindsay, the chief investigator who is leading the study at Queen Mary University of London, said: “Despite the introduction of new drugs, there are still many patients who don’t respond, or gradually lose response, to all available treatments. Although surgery with the formation of a stoma may be an option that allows patients to return to normal daily activities, it is not suitable in some and others may not want to consider this approach.

“We’re hoping that by completely resetting the patient’s immune system through a stem cell transplant, we might be able to radically alter the course of the disease. While it may not be a cure, it may allow some patients to finally respond to drugs which previously did not work.”

Patients in Scotland will be recruited through NHS Lothian with academics from Edinburgh University among those involved in the trial. Patients will also be recruited in Cambridge, Liverpool, London, Nottingham, Oxford and Sheffield.

The use of stem cell transplants to wipe out and replace patients’ immune systems has recently been found to be successful in treating multiple sclerosis, another auto-immune condition.

The new clinical trial, called ‘ASTIClite’, is a follow up to a previous stem cell trial in 2015 which found that many patients did experience some benefit from the treatment.