Long-Term Changes in the Expanded Disability Status Scale After Autologous Hematopoietic Stem Cell Transplantation in Patients with Multiple Sclerosis: A Single-Program Cohort of 1,657 Patients

Background Autologous hematopoietic stem cell transplantation (AHSCT) is an immune-reconstitution strategy for selected patients with multiple sclerosis (MS). Large real-world studies with long-term disability assessments remain limited. Objective To evaluate longitudinal changes in Expanded Disability Status Scale (EDSS) scores after AHSCT and to determine the proportions of patients achieving clinically meaningful improvement, stability, or progression. Materials and Methods This retrospective longitudinal cohort included 1,657 patients with MS who underwent AHSCT within HSCT México, a single clinical program operating at sites in Puebla and Monterrey, Mexico, between November 2012 and July 2026. Baseline EDSS scores were assigned by a neurologist. At follow-up, EDSS scores were obtained from a neurologist assessment when available and when a neurologist-assigned EDSS was not available, the score was derived using a structured EDSS calculator during the scheduled follow-up assessment. Clinically meaningful improvement was defined as a decrease of at least 1.0 EDSS point, progression as an increase of at least 1.0 point, and stability as a change of less than 1.0 point in either direction. Outcomes were also examined according to relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), and primary progressive MS (PPMS) phenotypes. Results Complete baseline–follow-up EDSS pairs were available for 675 patients at 3 months (40.7%), 549 at 6 months (33.1%), 578 at 12 months (34.9%), 350 at 18 months (21.1%), 361 at 24 months (21.8%), 245 at 36 months (14.8%), and 106 at 60 months (6.4%). Mean EDSS decreased significantly at 3 months (mean change, -0.18; 95% CI, -0.26 to -0.0; p < 0.001), 6 months (-0.16; 95% CI, -0.26 to -0.06; p = 0.001), 12 months (-0.36; 95% CI, -0.47 to -0.26; p < 0.001), 18 months (-0.24; 95% CI, -0.39 to -0.09; p = 0.002), and 24 months (-0.25; 95% CI, -0.40 to -0.10; p = 0.001). No significant differences from baseline were observed at 36 months (-0.13; 95% CI, -0.32 to 0.05; p = 0.144 ) or 60 months (0.02; 95% CI, -0.31 to 0.35; p = 0.910). Wilcoxon analyses yielded concordant findings, with the largest nonparametric effect observed at 12 months (r = 0.334). At 12 months, 27.2% of patients improved, 62.5% remained stable, and 10.4% progressed. At 60 months, 26.4% improved, 48.1% remained stable, and 25.5% progressed; thus, 74.5% of patients with long-term paired data have remained stable or improved. Conclusions AHSCT was associated with significant reductions in EDSS through 60 months, with the greatest improvement observed at 12 months; most patients with available long-term data remained stable or improved.