Impact of Autologous Mesenchymal Stem Cell Infusion on Neuromyelitis Optica Spectrum Disorder: A Pilot, 2‐Year Observational Study

Summary Aims We evaluate safety and efficacy of autologous bone marrow‐derived mesenchymal stem cells ( MSC s) as a potential treatment for neuromyelitis optica spectrum disorder ( NMOSD ). Methods Fifteen patients with NMOSD were recruited. All patients received a single intravenous infusion of 1.0 × 10 8 autologous MSC within 3–4 generations derived from bone marrow. The primary endpoints of the study were efficacy as reflected by reduction in annualized relapse rates ( ARR s) and inflammatory lesions observed by MRI . Results At 12 months after MSC infusion, the mean ARR was reduced (1.1 vs. 0.3, P = 0.002), and the T2 or gadolinium‐enhancing T1 lesions decreased in the optic nerve and spinal cord. Disability in these patients was reduced ( EDSS , 4.3 vs. 4.9, P = 0.021; visual acuity, 0.4 vs. 0.5, P = 0.007). The patients had an increase in retinal nerve fiber layer thickness, optic nerve diameters and upper cervical cord area. We did not identify any serious MSC ‐related adverse events. At 24 months of MSC infusion, of 15 patients, 13 patients (87%) remained relapse‐free, the mean ARR decreased to 0.1; the disability of 6 patients (40%) was improved, and the mean EDSS decreased to 4.0. Conclusions This pilot trial demonstrates that MSC infusion is safe, reduces the relapse frequency, and mitigates neurological disability with neural structures in the optic nerve and spinal cord recover in patients with NMOSD . The beneficial effect of MSC infusion on NMOSD was maintained, at least to some degree, throughout a 2‐year observational period.