Background: During the last 15 years, high-dose chemotherapy with autologous hematopoietic stem cell transplantation (HSCT) has globally been performed for severe multiple sclerosis (MS). Most patients have been in progressive phase with long disease duration. As a rule, treatment effect has been minor or moderate.
Patients: Since 2004, we have performed HSCT in nine young patients with "malignant" relapsing-remitting MS. Criteria for treatment were short duration of disease; very frequent, severe relapses; recent improvement periods indicating potential for recovery after strong immunosuppression.
Findings: Median age at treatment was 27 (range 9-34) years, MS duration 26 (4-100) months, and annualized relapse rate 10 (4-12). Median Disability Status Scale (extended disability status scale, EDSS) at HSCT was 7.0 (3.5-8.0). Median follow-up time April 2008 is 29 (23-47) months. Median EDSS improvement is 3.5 (1.0-7.0), clearly surpassing most previous reports. One patient relapsed mildly with rapid recovery 7 months after HSCT. All patients are otherwise stable, median EDSS being 2.0 (0-6.0). Before HSCT, 61 relapses occurred in 82 patient months; during follow-up, one relapse in 289 patient months.
Conclusion: This small series of patients with "malignant" relapsing-remitting MS suggests HSCT to be an effective treatment option for this relatively rare disease course. It further suggests that future criteria for HSCT in MS should be close to the present ones.