Factors associated with outcomes following autologous haematopoietic stem cell transplantation for multiple sclerosis.

Background: Autologous haematopoietic stem cell transplantation (AHSCT) has emerged as a highly effective treatment for relapsing-remitting multiple sclerosis (RRMS), though patient selection remains challenging. The degree to which disease-modifying therapies (DMTs) and procedure-related complications affect treatment outcomes is unclear. The objective of this study was to investigate the factors that might influence outcomes following AHSCT.

Methods: Data from the multicentre, retrospective cohort study Haematopoietic Stem Cell Transplantation for Treatment of Multiple Sclerosis in Sweden (AutoMS-Swe) were analysed, comprising 174 patients with RRMS who received AHSCT before 1 January 2020. Primary outcomes included inflammatory disease activity, confirmed disability worsening (CDW) and overall evidence of disease activity. Confirmed disability improvement was investigated as a secondary outcome. Associations between variables of interest and outcomes were assessed using univariable Cox proportional hazards models.

Results: Patients who received rituximab as the last DMT before AHSCT had a reduced hazard of inflammatory disease activity (HR 0.18, 95% CI 0.04 to 0.78). Epstein-Barr virus detection was associated with a higher hazard of inflammatory disease activity (HR 2.3, 95% CI 1.05 to 5.07). CDW was associated with longer disease durations (HR 1.09, 95% CI 1.00 to 1.19) and was negatively associated with gadolinium-enhancing lesions (HR 0.08, 95% CI 0.01 to 0.64). No CDW events occurred in treatment-naive patients.

Conclusions: Prior rituximab treatment appears to be protective against inflammatory activity after AHSCT. Disease duration and gadolinium-enhancing lesions are major determinants of disability following AHSCT.