Efficacy and Safety of Autologous Hematopoietic Stem Cell Transplantation in Relapsing-Remitting Multiple Sclerosis: A Systematic Review

Abstract

Introduction: Multiple Sclerosis (MS) is a chronic autoimmune disease of the central nervous system. For aggressive forms of MS unresponsive to standard disease-modifying therapies, autologous hematopoietic stem cell transplantation (aHSCT) has been proposed as a method to "reset" the immune system. This review assesses the efficacy of aHSCT in halting disease progression and its associated safety profile.

Methods: We conducted a systematic review of cohort studies and clinical trials from the MEDLINE and Embase databases. Studies with at least 10 patients with relapsing-remitting MS undergoing aHSCT and reporting on "No Evidence of Disease Activity" (NEDA) and transplant-related mortality (TRM) were included.

Results: Thirty-one studies comprising 2,150 patients were analyzed. The pooled proportion of patients achieving NEDA at 5 years post-transplant was 68% (95% CI: 61-75%). The most significant benefits were observed in younger patients with highly active inflammatory disease and shorter disease duration. However, the pooled TRM was 1.5% (95% CI: 0.9-2.3%), with most deaths occurring within the first 100 days due to infection or conditioning regimen toxicity.

Discussion: aHSCT offers the potential for long-term, treatment-free remission for a significant portion of patients with aggressive MS, an outcome not typically achieved with current pharmaceuticals. The main limitation is the risk of serious adverse events and mortality, which necessitates careful patient selection and management at experienced centers.

Conclusion: Autologous HSCT is a highly effective therapy for controlling inflammatory activity in selected patients with MS, but it carries significant risks. Its use should be reserved for patients with aggressive disease who have failed to respond to high-efficacy therapies.