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Brain parenchymal lesions are frequently observed on conventional magnetic resonance imaging (MRI) scans of patients with neuromyelitis optica (NMO) spectrum disorder, but the specific morphological and temporal patterns distinguishing them unequivocally from lesions caused by other disorders have not been identified. This literature review summarizes the literature on advanced quantitative imaging measures reported for patients with NMO spectrum disorder, including proton MR spectroscopy, diffusion tensor imaging, magnetization transfer imaging, quantitative MR volumetry, and ultrahigh-field strength MRI. It was undertaken to consider the advanced MRI techniques used for patients with NMO by different specialists in the field. Although quantitative measures such as proton MR spectroscopy or magnetization transfer imaging have not reproducibly revealed diffuse brain injury, preliminary data from diffusion-weighted imaging and brain tissue volumetry indicate greater white matter than gray matter degradation. These findings could be confirmed by ultrahigh-field MRI. The use of nonconventional MRI techniques may further our understanding of the pathogenic processes in NMO spectrum disorders and may help us identify the distinct radiographic features corresponding to specific phenotypic manifestations of this disease.

ImportanceMost patients with relapsing-remitting (RR) multiple sclerosis (MS) who receive approved disease-modifying therapies experience breakthrough disease and accumulate neurologic disability. High-dose immunosuppressive therapy (HDIT) with autologous hematopoietic cell transplant (HCT) may, in contrast, induce sustained remissions in early MS.ObjectiveTo evaluate the safety, efficacy, and durability of MS disease stabilization through 3 years after HDIT/HCT.Design, setting, and participantsHematopoietic Cell Transplantation for Relapsing-Remitting Multiple Sclerosis (HALT-MS) is an ongoing, multicenter, single-arm, phase 2 clinical trial of HDIT/HCT for patients with RRMS who experienced relapses with loss of neurologic function while receiving disease-modifying therapies during the 18 months before enrolling. Participants are evaluated through 5 years after HCT. This report is a prespecified, 3-year interim analysis of the trial. Thirty-six patients with RRMS from referral centers were screened; 25 were enrolled.InterventionsAutologous peripheral blood stem cell grafts were CD34+ selected; the participants then received high-dose treatment with carmustine, etoposide, cytarabine, and melphalan as well as rabbit antithymocyte globulin before autologous HCT.Main outcomes and measuresThe primary end point of HALT-MS is event-free survival defined as survival without death or disease activity from any one of the following outcomes: (1) confirmed loss of neurologic function, (2) clinical relapse, or (3) new lesions observed on magnetic resonance imaging. Toxic effects are reported using National Cancer Institute Common Terminology Criteria for Adverse Events.ResultsGrafts were collected from 25 patients, and 24 of these individuals received HDIT/HCT. The median follow-up period was 186 weeks (interquartile range, 176-250) weeks). Overall event-free survival was 78.4% (90% CI, 60.1%-89.0%) at 3 years. Progression-free survival and clinical relapse-free survival were 90.9% (90% CI, 73.7%-97.1%) and 86.3% (90% CI, 68.1%-94.5%), respectively, at 3 years. Adverse events were consistent with expected toxic effects associated with HDIT/HCT, and no acute treatment-related neurologic adverse events were observed. Improvements were noted in neurologic disability, quality-of-life, and functional scores.Conclusions and relevanceAt 3 years, HDIT/HCT without maintenance therapy was effective for inducing sustained remission of active RRMS and was associated with improvements in neurologic function. Treatment was associated with few serious early complications or unexpected adverse events.

MS is an inflammatory CNS disorder, which typically occurs in early adulthood and rarely in children. Here we tested whether functional maturation of innate immune cells may determine susceptibility to CNS autoimmune disease in EAE. Two-week-old mice were resistant to active EAE, which causes fulminant paralysis in adult mice; this resistance was associated with an impaired development of Th1 and Th17 cells. Resistant, young mice had higher frequencies of myeloid-derived suppressor cells and plasma-cytoid DCs. Furthermore, myeloid APCs and B cells from young mice expressed lower levels of MHC class II and CD40, produced decreased amounts of proinflammatory cytokines, and released enhanced levels of anti-inflammatory IL-10. When used as APCs, splenocytes from 2-week-old mice failed to differentiate naive T cells into Th1 and Th17 cells irrespective of the T-cell donor's age, and promoted development of Treg cells and Th2 cells instead. Adoptive transfer of adult APCs restored the ability of 2-week-old mice to generate encephalitogenic T cells and develop EAE. Collectively, these findings indicate that the innate immune compartment functionally matures during development, which may be a prerequisite for development of T-cell-mediated CNS autoimmune disease.