Characterization of Japanese multiple sclerosis patients with progression independent of relapse activity: A 2-year multicenter cohort study.

Progression independent of relapse activity (PIRA) is prevalent among Caucasian patients with relapsing and remitting multiple sclerosis (RRMS). However, there is limited knowledge regarding the characteristics of PIRA in Asian patients with RRMS. Therefore, we retrospectively analyzed the clinical and radiological progression of 95 Japanese patients with RRMS during a 2-year observation period. PIRA was observed in three patients who were characterized by young age, large T2 lesion volume, and great reduction in brain volume. Despite having highly active disease, fewer patients with PIRA (33.3%) were treated with high-efficacy drugs compared with those without disease activity (60.7%).

Japanese translation and validation of the 12-item Multiple Sclerosis Walking Scale version 2.

BACKGROUND: Disability in ambulation has a critical impact on activities of daily living in patients with multiple sclerosis (MS). The 12-item Multiple Sclerosis Walking Scale (MSWS-12) is a self-reported instrument developed to assess the impact of MS on walking. The scale's 12 items assess various aspects of walking-related tasks during the past 2 weeks. MSWS-12 has been used in multiple clinical studies and translated into several languages. In the present study, we translated the MSWS-12 into Japanese and evaluated its psychometric properties in a cross-sectional study. METHODS: The original English MSWS-12 version 2 (v2) was translated into Japanese through a standard procedure. Sixty consecutive Japanese MS patients completed the newly prepared Japanese MSWS-12v2 questionnaire and repeated the test 14 days later. Physical disability was assessed by the Expanded Disability Status Scale (EDSS), Timed 25-foot Walk (T25FW), and 9-hole Peg Test (9HPT). Cognitive performance was evaluated using the Processing Speed Test (PST). Fatigue and health-related quality of life were assessed using the Japanese versions of the Fatigue Severity Scale (FSS) and the Functional Assessment of MS (FAMS). RESULTS: The mean age of the patients was 42.5 years, with median disease duration of 10 years, and median EDSS of 2.0 (range 0, 6.5). Forty-seven patients (78.3 %) had relapsing-remitting, 9 (15.0 %) had secondary-progressive, and 4 (6.7 %) had primary-progressive phenotypes. The median score of the MSWS-12v2 was 5.95 (interquartile range 0, 50.6). Twenty-seven patients (45 %) scored the lowest possible score (0 points), while one (1.7 %) scored the highest possible score (100 points). Cronbach's alpha was 0.98 (95 % confidence interval [CI] 0.97, 0.98), and the test-retest intraclass correlation was 0.95 (95%CI 0.94, 0.96). MSWS-12v2 score was strongly correlated with EDSS (Spearman's ρ = 0.73 [95%CI 0.58, 0.83]), T25FW (ρ = 0.70 [95%CI 0.55, 0.81]), and total FAMS score (ρ = -0.80 [95%CI -0.88, -0.69]), and moderately correlated with 9HPT (ρ = 0.65 [95%CI 0.47, 0.77] for the dominant hand; ρ = 0.62 [95%CI 0.43, 0.75] for the non-dominant hand), PST (ρ = -0.65 [95%CI -0.78, -0.47]), and FSS (ρ = 0.68 [95%CI 0.52, 0.80]). Among the subcomponents of FAMS, the mobility subcomponent showed the most robust correlation with MSWS-12v2 score (ρ = -0.91 [95%CI -0.94, -0.81]). In patients with minimal or no objective disability (EDSS < 3.0, n = 40), only the mobility subcomponent of FAMS was strongly correlated with MSWS-12v2 score (ρ = -0.76 [95% CI -0.87, -0.58]). In contrast, correlations of MSWS-12v2 score with EDSS and T25FW were weak in this subgroup (ρ = 0.28 [95%CI -0.03, 0.55] for EDSS; ρ = 0.25 [95%CI -0.06, 0.52] for T25FW). Response patterns for the single items showed that 32.5 % of the patients with EDSS below 3.0 reported having problems with balance, followed by climbing stairs and standing while doing things (both 25 %). CONCLUSION: The Japanese version of the MSWS-12v2 developed in this study is reliable, valid, and helpful for screening walking disability in Japanese MS patients, including those with minimal objective disability.

Safety and Effectiveness of Satralizumab in Japanese Patients with Neuromyelitis Optica Spectrum Disorder: A 6-month Interim Analysis of Post-marketing Surveillance.

INTRODUCTION: Satralizumab, an anti-interleukin-6 receptor antibody, is approved in Japan for relapse prevention in neuromyelitis optica spectrum disorder (NMOSD) and is undergoing post-marketing surveillance (PMS) of clinical use. We aimed to describe the real-world safety and effectiveness of satralizumab in Japanese patients with NMOSD. METHODS: This is an ongoing PMS (planned completion: February 2027). This 6-month interim analysis assessed the safety and effectiveness of satralizumab in Japanese patients with NMOSD using data collected from August 2020 to July 2021. RESULTS: Among 570 patients who participated, 523 (91.75%) were female and the mean ± standard deviation (SD) age was 52.4 ± 14.1 years. At baseline, NMOSD expanded disability status scale mean ± SD was 4.19 ± 2.19; 490 (85.96%) patients used glucocorticoids and 277 (48.59%) patients used immunosuppressants concomitantly. Of 570 satralizumab-treated patients, 85 (14.91%) had discontinued satralizumab treatment at 6 months. For the overall adverse drug reactions (ADRs), 76.22 (66.07-87.48) events/100 person-years occurred in 118 (20.70%) patients, and infections occurred in 28 (4.91%) patients. Serious infections occurred in 18 (3.15%) patients, with an event rate of 9.05 (5.80-13.47) events/100 person-years. Of the 24 events of serious infections, respiratory tract infections (29.17%; 7) and urinary tract infections (25.00%; 6) were the most common serious infection events. One fatal ADR (septic shock) suspected to be related to satralizumab was reported. The mean ± SD glucocorticoid dose reduced from 12.28 ± 10.17 mg/day at the index date to 8.11 ± 7.30 mg/day at 6 months. The Kaplan-Meier cumulative relapse-free rate (95% confidence interval) was 94.59% (92.25-96.23) at 6 months. CONCLUSION: In this study, satralizumab was found to be safe, well tolerated, and effective in patients with NMOSD in routine clinical practice. The results are consistent with those of previous clinical trials. The safety and effectiveness of satralizumab in Japanese patients with NMOSD will be analyzed over the 6-year surveillance period. TRIAL REGISTRATION: UMIN Clinical Trials Registry, UMIN000041047.

[Thymoma-associated generalized myasthenia gravis complicated with anti-VGKC complex antibody-associated limbic encephalitis: a case report].

We present a case of a 54-year-old woman. She was attending our department for thymoma-associated generalized myasthenia gravis. While she was treated with intravenous immunoglobulins for the exacerbation of myasthenic symptoms, she suddenly lost her consciousness for the first time and continued to have mild disorientation along with anterograde and retrograde amnesia afterwards. The symptoms improved after steroid pulse therapy. After searching for autoantibodies, she was diagnosed with anti-VGKC complex antibody-associated limbic encephalitis. As one-third of cases are complicated by thymoma, anti-VGKC complex antibody-positive limbic encephalitis has the aspect of a paraneoplastic neurological syndrome. In this case, masses suspected to be a recurrence of thymoma were found. In cases of thymoma, involvement of anti-VGKC complex antibodies should be considered when central nervous system symptoms appear, and when anti-VGKC complex antibodies are positive, recurrence or exacerbation of thymoma should be considered.

Processing speed test: Results from a Japanese normative sample of healthy participants compared with a US normative sample.

BACKGROUND: The Processing Speed Test (PST), a validated iPad®-based cognitive screening test for MS, has been applied to the cognitive assessment of Japanese MS patients using US normative data. METHODS: To develop PST normative data from Japanese healthy volunteers and compare the PST score distribution between Japanese and US healthy volunteers, 254 healthy Japanese-speaking volunteers were enrolled and stratified by age (20-65 years). Potential participants with a Mini-Mental State Examination score < 27 were excluded. PST raw scores (total correct) were from the Japan cohort and compared with age-restricted US normative data and propensity score-matched data created by matching sex, age, and educational level from a published study of 428 healthy participants. PST score distributions and standardized z-scores were compared using t-test and Kolmogorov-Smirnov test statistics. RESULTS: The mean age of the Japan cohort was 44.1 years. The PST scores of Japanese volunteers were significantly different from those of the age-restricted (mean ± SD 61.8 ± 10.1 vs 53.7 ± 10.8; p < 0.001) and the propensity score-matched US cohort (62.1 ± 10.1 vs 53.3 ± 10.6; p < 0.001). CONCLUSION: Regression analyses centered on US normative data could underestimate disease severity in Japanese MS patients, suggesting that separate normative data should be considered for each population sample.

Health-related quality of life in Japanese patients with multiple sclerosis.

OBJECTIVES: Neurological disabilities, especially physical issues, can adversely affect the daily lives of people with multiple sclerosis (MS) and negatively impact their health-related quality of life (HRQOL). On the other hand, physical and psychiatric symptoms are variable in people with MS, and QOL can be influenced by cultural and educational background. This study aimed to evaluate the association of HRQOL with disabilities, fatigue, and depression in Japanese subjects with MS. METHODS: Evaluation of HRQOL, fatigue, and depression was performed in 184 Japanese individuals with MS, using the Functional Assessment of MS (FAMS), Fatigue Severity Scale (FSS), and Beck Depression Inventory-Second Edition (BDI-II), respectively. RESULTS: Multiple linear regression analysis demonstrated negative correlations of the Expanded Disability Status Scale (EDSS) with scores on the FAMS subscales of mobility, symptoms, thinking and fatigue, total FAMS, and additional concerns. The FSS score had negative correlations with mobility, symptoms, emotional well-being, thinking and fatigue, total FAMS, and additional concerns. There were negative correlations between BDI-II scores and all items of FAMS. CONCLUSIONS: HRQOL had relatively close correlations with disabilities and fatigue, and depression had an especially close relationship with HRQOL.

Smoking and younger age at onset in anti-acetylcholine receptor antibody-positive myasthenia gravis.

Smoking is a known risk factor for the development and progression of several autoimmune diseases. Previous studies have pointed out the association of smoking with the development and worsening of symptoms in myasthenia gravis (MG), but further investigation is necessary to confirm this association. Smoking history was investigated in a cross-sectional study of 139 patients with anti-acetylcholine receptor antibody-positive MG, and the association of smoking history with the age at the onset of MG was analyzed. Patients who had been smoking at the onset of MG were significantly younger compared with those who had never smoked or had quit before the onset of MG. A linear regression analysis adjusting for sex and the presence/absence of thymoma showed a significant association between smoking at onset and younger age at onset (regression coefficient -9.05; 95% confidence interval, -17.6, -0.51; p = 0.039). Among patients with smoking exposure within 10 years prior to or at the onset of MG, women were significantly younger at the onset of MG compared with men. Our results suggest that smoking is an independent risk factor for the earlier development of anti-acetylcholine receptor antibody-positive MG and further support the putative link between smoking and MG.

Stages of brain volume loss and performance in the Brief International Cognitive Assessment for Multiple Sclerosis.

BACKGROUND: Cognitive dysfunction occurs in a substantial proportion of patients with multiple sclerosis (MS), negatively affects their daily activities, and is associated with poor prognosis. Cognitive dysfunction in MS can extend across multiple cognitive domains, depending on the patterns and extent of the brain regions affected. Therefore, a combination of tests, including the Brief International Cognitive Assessment for MS (BICAMS), that assess different aspects of cognition is recommended to capture the full picture of cognitive impairment in each patient. However, the temporal relationships between the progression of the MS brain pathology and the performances in different cognitive tests remain unclear. METHODS: Global and regional brain volume data were obtained based on T1-weighted magnetic resonance imaging from 61 patients with MS, and hierarchical cluster analysis was performed using these brain volume data. Cognitive function was assessed using the three subcomponents of the BICAMS: the Symbol Digit Modalities Test (SDMT), California Verbal Learning Test Second Edition (CVLT2), and Brief Visuospatial Memory Test-Revised (BVMTR). Clinical characteristics, patterns of regional brain volume loss, and cognitive test scores were compared among clusters. RESULTS: Cluster analysis of the global and regional brain volume data classified patients into three clusters (Clusters 1, 2, and 3) in order of decreasing global brain volume. A comparison of the clinical profiles of the patients suggested that those in Clusters 1, 2, and 3 are in the early, intermediate, and advanced stages of MS, respectively. Pair-wise analysis of regional brain volume among the three clusters suggested brain regions where volume loss starts early and continues throughout the disease course, occurs preferentially at the early phase, or evolves relatively slowly. SDMT scores differed significantly among the three clusters, with a decrease from Clusters 1 to 3. BVMTR scores also declined in this order, whereas the CVLT2 was significantly impaired only in Cluster 3. CONCLUSION: Our results suggest that SDMT performance declines in conjunction with brain volume loss throughout the disease course of MS. Performance in the BVMTR also declines in line with the brain volume loss, but impairment in the CVLT2 becomes particularly apparent at the late phase of MS.

High-efficacy therapy reduces subcortical grey matter volume loss in Japanese patients with relapse-onset multiple sclerosis: A 2-year cohort study.

BACKGROUND: Different treatment strategies can have varying effects on disability and whole brain volume in patients with multiple sclerosis (MS). However, the association between regional brain volume and treatment efficacy is currently unclear. Our objective was to determine whether whole brain volume, as well as the regional volume of cortical and subcortical grey matter, differ with the administration of high-efficacy therapy (HET) versus low-efficacy therapy (LET). METHODS: We evaluated clinical data and change in regional brain volume in 44 patients with relapse-onset MS, who underwent HET (n = 19) or LET (n = 25). Regional brain volume was determined with three-dimensional T1-weighted magnetic resonance imaging using FreeSurfer. The association between volume change and treatment type was assessed via generalised linear mixed models (GLMMs). RESULTS: During the observation period (2.0 ± 0.16 years), the proportion of patients with a "no evidence of disease activity-3″ status was significantly greater in those who underwent HET versus LET (p = 0.012). HET was positively associated with volume changes in the cortex (ß = 0.64, p = 0.0499), left (ß = 0.98, p = 0.0033) and right (ß = 0.77, p = 0.019) caudate and right putamen (ß = 0.87, p = 0.0077), after adjusting for age, sex, and MS severity scores in the GLMMs. Further correction for multiple comparisons by false discovery rate revealed that HET was consistently associated with the volume changes of the left caudate (p = 0.049) and right putamen (p = 0.049). CONCLUSION: HET can improve the mid-term prognosis of Japanese patients with relapse-onset MS by reducing disease activity and regional brain volume loss.

Correlation of the symbol digit modalities test with the quality of life and depression in Japanese patients with multiple sclerosis.

BACKGROUND: This study aimed to evaluate the association between cognitive impairment and health-related quality of life (HRQOL), fatigue, and depression in Japanese patients with multiple sclerosis (MS). METHODS: The Brief International Cognitive Assessment for MS (BICAMS) was performed in 184 Japanese patients with MS. The Functional Assessment of MS (FAMS), Fatigue Severity Scale (FSS), and Beck Depression Inventory-Second Edition (BDI-II) were used to evaluate HRQOL, fatigue, and depression, respectively. RESULTS: Multiple linear regression analysis demonstrated positive correlations of the Symbol Digit Modalities Test (SDMT) with the scores on the FAMS subscales of mobility, symptoms, emotional well-being, and additional concerns and with the total FAMS score even after controlling for the Expanded Disability Status Scale score, age at examination, and duration of education. The SDMT score in the BICAMS battery had negative correlations with the BDI-II score, as revealed by multiple linear regression analysis. None of the three tests in the BICAMS had any correlation with the FSS score. CONCLUSION: The SDMT has a significant relationship with HRQOL and depression in Japanese patients with MS.

Association of Smoking and Generalized Manifestations of Myasthenia Gravis.

Objective Smoking is a known risk factor for the development and progression of autoimmune diseases. Previous studies in ocular myasthenia gravis (MG) patients showed that smoking is associated with the severity of symptoms and progression to generalized MG. However, whether smoking affects MG symptoms in patients with a broader clinical spectrum of presentations is unknown. Therefore, in this study, the associations of smoking with the clinical characteristics of MG were analyzed in a cohort of patients including those with generalized, seronegative, and thymoma-associated MG. Methods The smoking history was investigated in a cross-sectional study of 187 patients with MG followed in a referral hospital for neurology. The association of smoking with MG-activities of daily living score at survey, the presence of generalized manifestations, and the age of onset was assessed using multiple regression models. Results Neither current nor prior smoking habit was associated with the MG-activities of daily living score at survey. However, smoking exposure after MG onset was significantly associated with the presence of generalized manifestations during the disease course (odds ratio, 3.57; 95% confidence interval, 1.04, 12.3). The smoking history before or at onset of MG was not associated with the age of onset. Conclusion Smoking exposure after the onset is associated with generalized manifestations of MG in our cohort of patients with a broad clinical spectrum of presentations.

B-cell depletion therapy for multiple sclerosis.

Since the initial observation of increased immunoglobulin concentrations in the cerebrospinal fluid of multiple sclerosis (MS) patients in the 1940s, B cells have been considered to participate in the pathology of MS through the production of autoantibodies reactive against central nervous system antigens. However, it is now recognized that B cells contribute to MS relapses via antibody-independent activities, including the presentation of antigens to T cells and the release of pro-inflammatory cytokines. In addition, the recent identification of B cell-rich follicle-like structures in the meninges of progressive MS patients suggests that the pathogenic roles of B cells also exist at the progressive phase of this disease. Recently, large-scale clinical trials have demonstrated the efficacy of B-cell depletion therapy using anti-CD20 antibodies in relapsing as well as primary progressive MS. B-cell depletion therapy has become an essential treatment option for MS based on its unique benefit to risk balance in relapsing MS, and because it is the only drug that has been shown to be effective in primary progressive MS to date.

Seasonal fluctuations in serum levels of vitamin D in Japanese patients with multiple sclerosis.

We explored the presence of seasonal fluctuations in serum vitamin D levels and potential relationship between vitamin D levels and disease severity or prognosis in patients with multiple sclerosis (MS) in northern Japan. Serum levels of 25(OH)D in spring were significantly lower than in summer and autumn, whereas no differences in 1,25(OH)2D levels were demonstrated among four seasons. Seasonal fluctuations in 25(OH)D were demonstrated in patients with EDSS ≤3.5, but not in those with EDSS≥4.0. Negative correlations between 25(OH)D and EDSS or MSSS were found in each season. Seasonal fluctuations in 25(OH)D levels may be affected by physical disabilities.

[Relapsing-Remitting Multiple Sclerosis].

Multiple sclerosis (MS) is an immune-mediated inflammatory demyelinating disease of the central nervous system. There are neither diagnostic tests nor markers for MS. Other causes must be excluded thoroughly before an MS diagnosis is considered definitive. The relapsing-remitting type is a major clinical course in MS. Most disease-modifying drugs (DMDs) target this clinical type. Many clinical studies have demonstrated that early intervention with DMDs may prevent disease progression and transition from relapsing-remitting MS to the secondary progressive type. There are windows of opportunity for DMDs. An adequate DMD should be used for the appropriate patient at the optimal time.

[Cognitive Impairment in Multiple Sclerosis].

Cognitive impairment is one of the major symptoms of multiple sclerosis (MS) and one that often remains unnoticed. An adequate battery should be used to evaluate cognitive function in patients with MS because cognitive impairment in MS typically involves specific deficits such as sustained attention and information processing speed rather than global cognitive decline. Cognitive impairment could influence patients' daily and social activities. It is not easy to improve cognitive impairment in patients with MS, and it is important to prevent the decline of function using disease-modifying drugs for MS.

Progressive Multifocal Leukoencephalopathy during Tocilizumab Treatment for Rheumatoid Arthritis.

A 61-year-old woman was diagnosed with rheumatoid arthritis 12 years ago and received multiple treatment regimens before achieving symptomatic stability with methotrexate plus tocilizumab, a humanized monoclonal antibody against the IL-6 receptor, about 2 years prior to the current presentation. Sixteen months after tocilizumab initiation, she exhibited dysarthria and disorientation; five months later, she was hospitalized with movement difficulties. Her neurological symptoms deteriorated thereafter, accompanied by enlarged cerebral white matter lesions on magnetic resonance imaging. A biopsy of the right frontal lesion confirmed progressive multifocal leukoencephalopathy (PML). While several therapeutic monoclonal antibodies have been linked to PML, this is the first case associated with tocilizumab.

[B-cell Depletion Therapy in Multiple Sclerosis].

Since the initial observation of increased immunoglobulin concentrations in the cerebrospinal fluid of patients with multiple sclerosis (MS) in the 1940s, B cells have been considered to participate in the pathology of MS through the production of autoantibodies reactive against central nervous system antigens. However, it is now recognized that B cells contribute to MS relapses by antibody-independent activities, including presenting antigens to T cells and releasing pro-inflammatory cytokines. In addition, the recent identification of B cell-rich follicle-like structures in the meninges of patients with MS suggests that pathogenic roles of B cells also exist at the progressive phase. Recently, large-scale clinical trials have demonstrated the efficacy of B-cell depletion therapy using ocrelizumab, an anti-CD20-antibody, in relapsing-remitting as well as primary progressive MS; these findings have led to the approval of ocrelizumab by the Food and Drug Administration and the European Medical Agency for treating these conditions. B-cell depletion therapy is an important treatment option for MS based on its favorable benefit to risk balance in relapsing remitting MS, and as it is the only drug that has currently been demonstrated to be effective in treating primary progressive MS.

Disease Exacerbation after the Cessation of Fingolimod Treatment in Japanese Patients with Multiple Sclerosis.

Objective In Japan, following the launch of dimethyl fumarate (DMF) after fingolimod as a disease-modifying drug in multiple sclerosis (MS), some patients switched from fingolimod to DMF. The aim of this study was to determine the follow-up status of MS patients who switched to DMF after fingolimod cessation. Methods Clinical and magnetic resonance imaging (MRI) data in 19 patients with MS who switched to DMF were collected for at least for 6 months after fingolimod cessation. Results Ten patients (52.6%) experienced clinical or MRI exacerbation after fingolimod cessation. The peripheral blood lymphocyte counts at the time of fingolimod cessation in those with disease exacerbation were significantly lower than in those without exacerbation. The patients with disease exacerbation were further classified into three groups based on MRI findings: those with some new T2-weighted lesions with or without gadolinium (Gd) enhancement (group I), those with more new and/or enlarged T2-weighted lesions with Gd enhancement compared to pre-fingolimod induction (group II), and those with multifocal tumefactive demyelinating lesions. In group II, the clinical disease activity, which was similar to that at fingolimod initiation in group I, was higher than the clinical disease activity observed before fingolimod initiation. Conversely, group III exhibited unexpected new MRI findings that were not evident before fingolimod initiation. Conclusion Cessation of fingolimod might precipitate rebound or reactivation of clinical disease in patients with MS, and careful follow-up is necessary for patients who discontinue fingolimod.

Beneficial effects of fingolimod in MS patients with high serum Sema4A levels.

We previously demonstrated that patients with multiple sclerosis (MS) of high serum Sema4A levels are resistant to IFN-ß therapy. To further elucidate the role of serum Sema4A as a biomarker for therapeutic stratification in MS patients, it is important to clarify the efficacy of other disease-modifying drugs (DMD) in those with high serum Sema4A levels. Thus, in this study we investigated whether fingolimod has beneficial effects on MS patients with high Sema4A levels. We retrospectively analyzed annualized relapse rate (ARR) and Expanded Disability Status Scale (EDSS) change in 56 relapsing-remitting multiple sclerosis (RRMS) patients who had been treated with fingolimod, including those who switched from IFN-ß therapy. The levels of Sema4A in the sera were measured by sandwich ELISA. The implications of Sema4A on the efficacy of fingolimod were investigated by administering recombinant Sema4A-Fc and fingolimod to mice with experimental autoimmune encephalomyelitis (EAE). Retrospective analysis of MS cohort (17 high Sema4A and 39 low Sema4A) demonstrated the effectiveness of fingolimod in those with high serum Sema4A levels, showing reduction of ARR (from 1.21 to 0.12) and EDSS progression (from 0.50 to 0.04). Consistent with this observation, improvement in the disease severity of EAE mice receiving recombinant Sema4A-Fc was also observed after fingolimod treatment. These data suggest that fingolimod could serve as a candidate DMD for managing the disease activity of MS patients with high Sema4A levels.

Fingolimod induces BAFF and expands circulating transitional B cells without activating memory B cells and plasma cells in multiple sclerosis.

Patients with multiple sclerosis (MS) who are treated with fingolimod have an increased proportion of transitional B cells in the circulation, but the underlying mechanism is not known. We hypothesized that B cell-activating factor of the tumor necrosis factor family (BAFF) is involved in the process. Compared with healthy controls and untreated MS patients, fingolimod-treated MS patients had significantly higher serum concentrations of BAFF, which positively correlated with the proportions and the absolute numbers of transitional B cells in blood. Despite the elevated concentrations of BAFF in fingolimod-treated MS patients, serum levels of soluble transmembrane activator and calcium-modulating cyclophilin ligand interactor, and B cell maturation antigen were not elevated. Our results show that fingolimod induces BAFF in the circulation and expands transitional B cells, but does not activate memory B cells or plasma cells in MS, which is favorable for the treatment of this disease.