Autologous haematopoietic stem cell transplantation for multiple sclerosis: a position paper and registry outline.

Autologous haematopoietic stem cell transplantation for multiple sclerosis Substantial progress has been made in the development of disease-modifying medications for multiple sclerosis (MS) during the last 20 years. However, in a relevant percentage of patients, the disease cannot completely be contained. Autologous haematopoietic stem cell transplantation (AHSCT) enables rebuilding of a new and healthy immune system and to potentially stop the autoimmune disease process for a long time. A number of studies documenting 4000 cases cumulatively over the past 20 years reported high efficacy of AHSCT in controlling MS inflammatory disease activity. These data and improved safety profiles of the treatment procedures spurred interest in using AHSCT as a treatment option for MS. An open call among MS neurologists as well as among experts in stem cell transplantation in Germany started in December 2021 to join a series of video calls to develop recommendations and outline a registry study project. We provide a consensus-based opinion paper authored by 25 experts on the up-to-date optimal use of AHSCT in managing MS. Current data indicate that patients are most likely to benefit from AHSCT if they are young, ambulatory, with high disease activity, that is, relapses or new magnetic resonance imaging (MRI) lesions. Treatment data with AHSCT will be collected within the German REgistry Cohort of autoLogous haematopoietic stem cell transplantation MS (RECLAIM). Further clinical trials including registry-based analyses and systematic follow-up are urgently needed to better define the optimal patient characteristics as well as the efficacy and safety profile of AHSCT compared with other high-efficacy therapies. These will help to position AHSCT as a treatment option in different MS disease stages.