IT was described as “close to curative” and “a breakthrough therapy” by some neurologists when the results of a long-running Canadian clinical trial into AHSCT were published in the Lancet last year.

Of the 24 participants severely disabled with aggressive, relapsing MS, 23 were walking, working and playing sports 13 years on from their stem cell transplant. One volunteer, Jennifer Molson, told how she had gone from living in assisted care, unable to work or walk, to dancing and even downhill ski-ing.

However, in an important reminder of the substantial risks associated with using chemotherapy to effectively wipe out the immune system, one patient did die from liver failure brought on by the treatment.

The findings are hugely significant for Scotland, which has the highest rate of MS in the world. Around 209 people per 100,000 in Scotland have MS, rising to as much as 402 per 100,000 in Orkney - four times the UK average. Patients are rightly perplexed therefore that while some patients can access AHSCT on the NHS in England, patients in Scotland have been refused. To be clear, the number getting HSCT on the NHS is small - restricted to only those with relapsing MS, not progressive, for whom available drug therapies have failed and who “are prepared to accept the significant risks of the procedure”. NHS England stresses that it is an option which should be “used rarely”.

Nonetheless, it is a bitter disparity for potentially eligible Scots patients who face paying £70,000 for private treatment - recently available in London - or go overseas, as far afield as Mexico, Russia or Israel. There is also a frustration that both the NHS and clinical trials, including those currently underway in London and Sheffield, restrict the therapy to relapsing MS when many with the progressive form - including Mrs Clarke - report life-changing results. In some cases it means being able to give up drugs that cost the health service £30,000 per year per patient.

A spokesman for the Scottish Government said it was an individual clinical decision. He said: “Whilst the vast majority of healthcare provided by NHS Scotland is delivered in Scotland, NHS boards can commission treatment in other countries on an ad hoc basis, particularly where highly specialised treatment is involved. Decisions to refer patients are for clinicians, based on agreed guidelines, which ensure best practice, equity of access and consistency of treatment for all patients.”