Reduced-intensity Immunoablation and Autologous Hematopoietic Stem Cell Transplantation (AHSCT) for Multiple Sclerosis

Inclusion Criteria: * Diagnosed with progressive multiple sclerosis with or without relapses * EDSS score between 1.5 and 7.0, including documented rapid progression over the previous year unresponsive to conventional therapies or no available treatment options * Aged between 18 and 60 with a history of at least one enhancing lesion on brain MRI * With absolute neutrophil count ≥ 1,000/mm\^3, platelet count ≥ 100,000/mm\^3 and hemoglobin ≥ 9.0 g/dL Exclusion Criteria: * Patients with cardiac, renal, pulmonary, hepatic, or other organ impairment that would limit their ability to receive dose-intensive immunosuppressive therapy, high-dose chemotherapy, and/or Autologous HSCT * Patients with any active or chronic infection e.g. uncontrolled viral, fungal, or bacterial infection * Uncontrolled diabetes * Patients who are seropositive for HIV1, HIV2, Hepatitis B Surface Antigen, and Hepatitis C * Patients whose life expectancy is severely limited by another illness * Patients with evidence of myelodysplasia or other non-autoimmune cytopenia * Patients having received a cytotoxic agent within one month prior to this study * Patients who are pregnant or at risk of pregnancy, including those unwilling to practice * Patients with psychiatric illness, mental deficiency, or cognitive dysfunction * Patients unable to give written informed consent in accordance with research ethics board guidelines