Clinical Report: Hematopoietic Stem Cell Transplantation in Autoimmune Disorders

Overview

Hematopoietic stem cell transplantation (HSCT) has emerged over 25 years as a treatment for severe, refractory autoimmune diseases (ADs), primarily multiple sclerosis and systemic sclerosis. Autologous HSCT aims to reset the immune system, inducing durable remission by ablating autoreactive cells and promoting immune tolerance.

Background

Autoimmune diseases often involve chronic immune dysregulation with loss of self-tolerance, leading to persistent inflammation and tissue damage. Traditional therapies may be insufficient for severe cases, prompting exploration of HSCT to reconstitute a more tolerant immune system. The European Society for Blood and Marrow Transplantation (EBMT) Autoimmune Diseases Working Party (ADWP) has compiled the largest global registry of HSCT in ADs, facilitating outcome analyses and treatment optimization. Advances in understanding immune aging and cellular dynamics have informed HSCT protocols and patient selection.

Data Highlights

Key Findings

• HSCT primarily targets severe, refractory autoimmune diseases, with multiple sclerosis and systemic sclerosis comprising approximately 80% of cases.
• Autologous HSCT involves mobilization and collection of peripheral blood stem cells, followed by conditioning regimens to ablate autoreactive immune cells.
• Immune reconstitution post-HSCT shows renewal of naïve B cells, restoration of thymic output, and re-emergence of regulatory lymphocyte populations, contributing to disease remission.
• Conditioning intensity varies widely and is tailored to disease and patient factors; reduced intensity regimens decrease treatment-related morbidity.
• The EBMT ADWP registry, with over 3700 transplants, supports improved outcomes linked to center experience, multidisciplinary care, and accreditation.
• Long-lived plasma cells persist in autoimmune pathology and represent potential therapeutic targets beyond HSCT.

Clinical Implications

HSCT should be considered for patients with severe, treatment-refractory autoimmune diseases after careful risk-benefit assessment and multidisciplinary evaluation. Tailoring conditioning regimens and graft manipulation techniques can optimize safety and efficacy. Ongoing registry data and mechanistic studies support HSCT as a standard-of-care option in select autoimmune conditions, particularly multiple sclerosis and systemic sclerosis.

Conclusion

Hematopoietic stem cell transplantation offers a promising therapeutic avenue for inducing durable remission in severe autoimmune diseases by resetting immune tolerance. Continued research and registry analyses will refine patient selection, conditioning protocols, and long-term outcomes.

References

1. ADWP of EBMT -- An Overview of Hematopoietic Stem Cell Transplantation and Cellular Therapies for Autoimmune Disorders