Stem Cell Transplant Reduces Relapses and Disability in RRMS, Study Suggests
Autologous hematopoietic stem cell transplant (AHSCT) induces a reduction in relapse rate and physical disability in patients with relapsing-remitting multiple sclerosis (RRMS) who respond inadequately to other treatments, a small study suggests.
The study, “Selective cognitive dysfunction and physical disability improvement after autologous hematopoietic stem cell transplantation in highly active multiple sclerosis,” was published in the journal Nature Scientific Reports.
AHSCT is an experimental approach to treat multiple sclerosis (MS) that is meant to rebuild a patient’s immune system in order to stop attacks on the brain and spinal cord.
The procedure begins with collecting a patient’s own (meaning autologous) healthy hematopoietic stem cells — immature cells that can develop into all types of blood cells — from the bone marrow. These cells are put back into the patient after a fairly non-aggressive combination of chemotherapy is given to kill the patients’ immune cells.
A team of researchers at the Vilnius University, in Lithuania, evaluated the effectiveness and safety of the AHSCT procedure in 24 patients (18 female, mean age 37.8 years) with highly active RRMS (mean disease duration of 8.6 years) who failed to respond to conventional therapies.
The aim of the study was to assess cognitive dysfunction and physical disability after AHSCT, to explore the potential factors influencing disability regression after the transplant, and to estimate the safety of low-dose immunosuppressive therapy in highly active relapsing MS patients.
Researchers assessed participants’ disability and cognition through changes in several functional measures, including the expanded disability status scale (EDSS) and the Brief International Cognitive Assessment for MS, which includes three cognitive domains measured by the symbol digit modalities test, brief visuospatial memory test revised, and California verbal learning test second edition.
Of the 24 patients, 13 (54.2%) completed a 24-month follow-up and were included in the efficacy analysis of AHSCT. From those, two (15.4%) had one relapse during the first year after AHSCT and three patients (23.1%) had one relapse during the second year after AHSCT.
The annualized relapse rate (ARR) was 2.7 one year before AHSCT and 1.9 at two years before AHSCT. After the AHSCT procedure, ARR dropped to 0.2 in the first year and to 0.3 in the second year. This represented an 89% reduction in ARR, when comparing the values at two years after AHSCT with those at two years before AHSCT.
The researchers also noted a reduction in disability progression (as measured by EDSS scores), with 84.6% of patients improving their disability score after AHSCT at month six and 76.9% at one year. Additionally, 76.9% of patients showed stable disability scores two years after the transplant.
“The findings of EDSS improvement in almost 85% of the patients suggest that disability may be often at least temporarily reversible in patients with highly active [relapsing] MS if they receive suitable and well-timed treatment,” the researchers wrote.
Using appropriate statistical models, researchers found that the clinical variable that explained the disability regression at months 6 and 12 after AHSCT was the disability progression over 6 months before AHSCT.
Improvements in cognition after AHSCT also were observed. Specifically, the scores of information processing speed and verbal learning, measured by the symbol digit modalities test, were significantly higher at month 12 after AHSCT (56.8) when compared to month three (48.3).
The score of brief visuospatial memory test revised that assesses visuospatial memory was slightly lower at month three (25.6) than before AHSCT (27.8), however, the difference was not significant.
The score of the California verbal learning test, which assesses verbal learning, was significantly higher at month 12 (63.6) than before AHSCT (55.2).
No new or active lesions were found on MRI after AHSCT, suggesting that all patients remained without radiological disease activity.
Furthermore, regarding safety, the incidence and severity of adverse events (side effects) after AHSCT were in the expected range and all were resolved. There were no transplant-related deaths reported.
Researchers noted several limitations to the study’s findings, including the low sample size and the fact that the patients’s assessment and follow-ups were provided at the same center without a comparative group.
Nonetheless, the “outcomes are highly promising, as compared to conventional MS treatment,” the researchers wrote. “Further research is needed to replicate these findings and to assess long-term outcomes and safety of AHSCT.”