Interleukin-6 Signaling Blockade Induces Regulatory Plasmablasts in Neuromyelitis Optica Spectrum Disorder.

BACKGROUND AND OBJECTIVES: Interleukin-6 receptor antibodies (IL-6R Abs), including satralizumab, are increasingly used to prevent relapse for neuromyelitis optica spectrum disorder (NMOSD). However, the detailed mechanism of action of this treatment on the lymphocyte phenotype remains unclear. This study focused on B cells in patients with NMOSD, hypothesizing that IL-6R Ab enables B cells to acquire regulatory functions by producing the anti-inflammatory cytokine IL-10. METHODS: Peripheral blood mononuclear cells were stimulated in vitro to induce the expansion of B-cell subsets, double-negative B cells (DNs; CD19+ IgD-, CD27-) and plasmablasts (PBs; CD19+, CD27hi, CD38hi). Whole B cells, DNs, or PBs were isolated after culture with IL-6R Ab, and IL-10 expression was quantified using quantitative PCR and a cytometric bead array. RNA sequencing was performed to identify the marker of regulatory PBs induced by IL-6R Ab. RESULTS: DNs and PBs were observed to expand in patients with NMSOD during the acute attacks. In the in vitro model, IL-6R Ab increased IL-10 expression in B cells. Notably, IL-10 expression increased in PBs but not in DNs. Using RNA sequencing, CD200 was identified as a marker of regulatory PBs among the differentially expressed upregulated genes. CD200+ PBs produced more IL-10 than CD200- PBs. Furthermore, patients with NMOSD who received satralizumab had a higher proportion of CD200+ PBs than patients during the acute attacks. DISCUSSION: Treatment with IL-6 signaling blockade elicited a regulatory phenotype in B cells and PBs. CD200+ PBs may be a marker of treatment responsiveness in the context of NMOSD pathophysiology.

Efficacy and safety of mycophenolate mofetil for steroid reduction in neuromyelitis optica spectrum disorder: a prospective cohort study.

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune inflammatory disease that can affect multiple generations and cause complications with long-term prednisolone treatment. This study aimed to evaluate the efficacy and safety of mycophenolate mofetil (MMF) in preventing NMOSD relapse while reducing prednisolone dosage. The trial involved nine patients with NMOSD who received MMF along with prednisolone dose reduction. MMF was effective in achieving prednisolone dose reduction without relapse in 77.8% of patients, with a significant decrease in mean annualized relapse rate. All adverse events were mild. The findings suggest that MMF could be a viable treatment option for middle-aged and older patients who require steroid reduction.Clinical trial registration number: jRCT, jRCTs051180080. Registered February 27th, 2019-retrospectively registered, https://jrct.niph.go.jp/en-latest-detail/jRCTs051180080.

Transcription Factor c-Maf Promotes Immunoregulation of Programmed Cell Death 1-Expressed CD8+ T Cells in Multiple Sclerosis.

BACKGROUND AND OBJECTIVES: Multiple sclerosis (MS) is an inflammatory demyelinating disease of the CNS. CD8+ T cells are prominently found at inflammatory sites. Recent advances in understanding checkpoint molecules, including programmed cell death 1 (PD-1), expressed on CD8+ T cells, highlight the immune regulatory roles of this T-cell subset; however, the role of CD8+ T cells in MS is unclear. Thus, we aimed to reveal the characteristics of PD-1-expressed (PD-1+) CD8+ T cells in MS. METHODS: We performed a cohort, case-control study for phenotyping analysis of PD-1+CD8+ T cells in disease remission and flare states using CSF and peripheral blood samples of 45 patients with MS or clinically isolated syndrome and 12 healthy subjects. We further analyzed the transcriptome of sorted PD-1+CD8+ T cells obtained from interferon (IFN)-ß-treated patients and validated their regulatory machinery using in vitro cell culture assays with lentiviral gene transfer. RESULTS: In the disease remission state, PD-1+CD8+ T cells were decreased in the peripheral blood of patients with MS and resolved in patients treated with IFN-ß treatment who showed immune regulatory cytokine interleukin (IL)-10 expression. In the disease flare state, we found that PD-1+CD8+ T cells were enriched in the CSF, which predicted a good response to subsequent IV steroid therapy. Transcriptome analysis of sorted PD-1+CD8+ T cells revealed the transcription factor c-Maf as a potential major regulator of the gene module, including multiple coinhibitory molecules. Furthermore, c-Maf expressed in CD8+ T cells induced PD-1 expression and production of IL-10 as well as suppressed alloactivated CD4+ T-cell survival. DISCUSSION: This study uncovered a favorable role of PD-1+CD8+ T cells against MS and demonstrated that c-Maf-driven IL-10 is an immune regulatory machinery.

Validation of the Guy's Neurological Disability Scale as a screening tool for cognitive impairment in multiple sclerosis.

OBJECTIVES: Cognitive impairment is a common symptom affecting daily activities of the patients with multiple sclerosis (MS). Various cognitive evaluation tests are available, yet most of them are complex and time-consuming to perform in outpatient clinics. In this study, we aimed to validate a Japanese version of the Guy's Neurological Disability Scale (GNDS) as a user-friendly tool to evaluate comprehensive disabilities in MS including cognitive function. METHODS: Questions of the GNDS were translated into Japanese and named GNDS-J. Forty-four patients were examined by the Expanded Disability Status Scale (EDSS), the Paced Auditory Serial Addition Test (PASAT), the Symbol Digit Modalities Test (SDMT), the vitality scale, and the GNDS-J in the same time at remission state. RESULTS: The GNDS-J scores correlated with the EDSS scores(r = 0.61), and inversely correlated with the PASAT2/1(r=-0.56/-0.49) scores and the SDMT scores (r=-0.68), whereas the GNDS-J did not show any correlation with the vitality scale. Furthermore, eleven patients were evaluated over 5 years for changes in these scores. Eight out of 11 patients had exacerbated GNDS, and all of these patients experienced clinical relapse during this period. CONCLUSION: The GNDS-J is a valid tool to perform in outpatient clinics, which could provide a comprehensive scale for evaluating symptoms of MS, thus the disease activity by repeated measure.

[A case of neurologic muscle weakness, ataxia, and retinitis pigmentosa (NARP) syndrome with a novel mitochondrial mutation m.8729 G>A].

We report a patient having classical clinical feature of neurologic muscle weakness, ataxia, and retinitis pigmentosa (NARP) and a novel mutation, m.8729 G>A in mitochondria DNA. The patient was referred to our hospital because of progressive ataxia in her limbs and trunk. She had a history of incapability of running long distances from childhood. Neurological examination revealed cerebellar ataxia, distal dominant muscle weakness in the limbs, hyporeflexia, hypoesthesia, myoclonus, sensorineural deafness, and retinitis pigmentosa. Magnetic resonance imaging (MRI) showed atrophy of brain stem and cerebellum as well as calcification of basal ganglia. In both serum and cerebrospinal fluid, lactate and pyruvate levels were elevated. Histological examination of biopsied muscle revealed chronic neurogenic changes without ragged red fibers. Genetic analysis of mitochondrial DNA (mtDNA) of the muscle revealed a heteroplasmic mutation, m.8729 G>A. Chemical analysis of the respiratory chain complexes in her muscle specimen demonstrated lower activities of complexes I and V. In our case, novel mutation of m.8729 G>A in mtDNA was indicated as the cause of NARP syndrome.