September 26, 2023

expert reaction to study of stem cells to treat MS

A study published in the Journal of Neurology Neurosurgery & Psychiatry looks at the use of stem cells to treat MS. 

Prof Ruth Dobson, Professor of Clinical Neurology at the Wolfson Institute of Population Health, QMUL, said:

“This is a paper using a ‘real-world’ patient database from Sweden. There is increasing interest in the use of autologous haematopoietic stem cell transplantation (AHSCT) as a treatment for MS, and particularly where this treatment should fit into existing treatment paradigms . The Swedish MS databases are good sources of this kind of data, as most people with MS are captured, and the proportion of patients followed up is high. However, it must be noted that some treatment pathways are unique to particular countries.

“Early trials of AHST raised concerns around safety and it is important to note that no patients died in this study as a result of AHST. However, 5 patients needed ITU admission and most patients required treatment of infections during their treatment. This would be in keeping with other, more recent studies, and highlights the need to select patients carefully for these kinds of treatments.

“At 10 years 65% patients had no evidence of disease activity, 75% at 5 years. This underlines the efficacy of this treatment in people with MS. We do need more comparative evidence, such as is being generated with STAR-MS (a UK study of AHST vs high efficacy treatments), in order to be able to contextualise the efficacy against other treatments that are now in increasingly common use.”

Dr Alena Pance, Senior Lecturer in Genetics at the University of Hertfordshire, said:

“This work is a retrospective study of the use of autologous Haematopoietic Stem Cell Transplantation (aHSCT) for the treatment of Relapsing-Remitting MS. HSCT has been widely used for a long time to treat blood diseases such as various types of leukaemia and in the mid-1990s became also a therapy for autoimmune diseases, including MS.

“In this case, the aim is to ‘re-set’ the immune system to stop it from reacting against ‘self tissues’. The idea is that Haematopoietic Stem Cells are extracted from the patient before ablating the immune system completely and then reconstituting it with the Haematopoietic Stem Cells from the patient. It has been shown that this process leads to a re-diversification of the immune system and as the Haematopoietic Stem Cells come from the patient there is no adverse reaction to the transplant.

“The study shows that aHSCT is safe and leads to a significant decrease of annual relapse and disability. Crucially, they find that over 3 years after aHSCT there was an increase in the number of patients with no disability as a consequence of MS from 13.3% to 45%. The number of patients with mild to severe disability at the start of treatment decreased from 82% to 51%, though while a decrease was observed in the number of patients with very severe disease, this was noticeable mainly in the first year post-treatment. Furthermore, a low number of patients required additional treatment and the improvement observed was long-lasting.

“The disability caused by MS is the result of damage or degradation of the myelin that envelops and protects the nerves of the central and peripheral nervous system. Though HST can generate only blood cells (of all types) and not cells of the neuronal system, re-setting the immune system stops the constant attack on myelin, which then gives a chance to the specialised repair cells called oligodendrocyte precursors to regenerate the damaged myelin. However the potential and extent of repair depends on the severity of the disease, which is why, as the study indicates, the effect on disability is greater the lower the severity of the disease is.

“The limitation of the study is the absence of control groups treated only with regular therapies, which makes it difficult to assess the magnitude of the effect of aHSCT. However a randomised controlled trial comparing aHSCT and Disease-Modifying Therapy (DMT) showed similar positive effects of aHSCT in terms of prolonged time to disease progression and better outcomes than DMT. The results indicate that patients would benefit from aHSCT and that this form of Stem cell Therapy can be safely performed in a clinical setting, representing a powerful clinical tool to successfully treat MS and restore function and quality of life to patients.”

‘Haematopoietic stem cell transplantation for treatment of relapsing-remitting multiple sclerosis in Sweden: an observational cohort study’ by Thomas Silfverberg et al. was published in the Journal of Neurology Neurosurgery & Psychiatry at 23:30 UK time Monday 25 September 2023.

DOI: 10.1136/jnnp-2023-331864

Declared interests

Alena Pance: I confirm I have no conflict of interest with regards to this study.

No others received.