Objective: To investigate the association between human herpesviruses and multiple sclerosis (MS), as well as between measles virus and MS. Methods: The authors identified prospectively collected serum samples from 73 MS cases and retrospective sera from 161 MS cases in two population-based serum bank registers. Analyses of IgG antibody responses in cases and matched referents were performed for Epstein-Barr virus (EBV [EBNA-1 and VCA]), human herpesvirus 6 (HHV-6), herpes simplex virus (HSV), varicella zoster virus (VZV), and measles. Results: All cases showed signs of past EBV infection. High activity to EBNA-1 and HHV-6 significantly (borderline significance for HHV-6) increased the risk for MS in prospective sera. A discrepancy between activities to EBNA-1 and VCA was striking in MS samples collected less than 5 years before relapsing-remitting MS onset, where high activity to EBNA-1 significantly increased, and high VCA activity significantly decreased the risk for MS. There was no support for major causal roles for HSV, VZV, or measles. Conclusion: Individuals who will develop MS exhibit an altered immune response against the EBV virus characterized by a high IgG activity to EBNA-1 in the absence of high activity to VCA, this being most pronounced in the 5-year period preceding MS onset.

In experimental autoimmune encephalomyelitis (EAE), CD4⁺self-reactive T cells target myelin components of the CNS. However, the consequences of an autoaggressive T cell response against myelin for neurons are currently unknown. We herein demonstrate that EAE induced by active immunization with an encephalitogenic myelin basic protein peptide dramatically reduces the loss of spinal motoneurons after ventral root avulsion in rats. Both brain-derived neurotophic factor (BDNF)- and neurotrophin-3 (NT-3)-like immunoreactivities were detected in mainly T and natural killer (NK) cells in the spinal cord. In addition, very high levels of BDNF, NT-3, and glial cell line-derived neurotrophic factor mRNAs were present in T and NK cell populations infiltrating the CNS. Interestingly, bystander recruited NK and T cells displayed similar or higher neurotrophic factor levels compared with the EAE disease-driving encephalitogenic T cell population. High levels of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) mRNAs were also detected, and both these cytokines can be harmful to several types of CNS cells, including neurons. However, treatment of embryonic motoneuron cultures with TNF-α or IFN-γ only had a deleterious effect in cultures deprived of neurotrophic factors. These results suggest that the potentially neurodamaging consequences of severe CNS inflammation are curbed by the production of several potent neurotrophic factors in leukocytes.

Objective: Many JC virus antibody‐positive relapsing–remitting multiple sclerosis (RRMS) patients who are stable on natalizumab switch to other therapies to avoid progressive multifocal leukoencephalopathy.Methods: We compared outcomes for all RRMS patients switching from natalizumab due to JC virus antibody positivity at 3 Swedish multiple sclerosis centers with different preferential use of rituximab and fingolimod (Stockholm, n = 156, fingolimod 51%; Gothenburg, n = 64, fingolimod 88%; Umeå, n = 36, fingolimod 19%), yielding a total cohort of N = 256 (fingolimod 55%).Results: Within 1.5 years of cessation of natalizumab, 1.8% (rituximab) and 17.6% (fingolimod) of patients experienced a clinical relapse (hazard ratio for rituximab = 0.10, 95% confidence interval [CI] = 0.02–0.43). The hazard ratio (favoring rituximab) for adverse events (5.3% vs 21.1%) and treatment discontinuation (1.8% vs 28.2%) were 0.25 (95% CI = 0.10–0.59) and 0.07 (95% CI = 0.02–0.30), respectively. Furthermore, contrast‐enhancing lesions were found in 1.4% (rituximab) versus 24.2% (fingolimod) of magnetic resonance imaging examinations (odds ratio = 0.05, 95% CI = 0.00–0.22). Differences remained when adjusting for possible confounders (age, sex, disability status, time on natalizumab, washout time, follow‐up time, and study center).Interpretation: Our findings suggest an improved effectiveness and tolerability of rituximab compared with fingolimod in stable RRMS patients who switch from natalizumab due to JC virus antibody positivity. Although residual confounding factors cannot be ruled out, the shared reason for switching from natalizumab and the preferential use of either rituximab or fingolimod in 2 of the centers mitigates these concerns. Ann Neurol 2016;79:950–958

Objective: To evaluate levels of neurofilament light (NFL) and glial fibrillary acidic protein (GFAP) in CSF from patients with multiple sclerosis (MS) in relation to clinical progress of the disease. Methods: CSF levels of NFL and GFAP were determined by sensitive ELISAs in 99 patients with different subtypes of MS, classified in terms of “ongoing relapse” or “clinically stable disease,” and 25 control subjects. Levels were compared with paraclinical data such as immunoglobulin G index and inflammatory cell count in the CSF, and the levels were related to Expanded Disability Status Scale score and progression index at clinical follow-up evaluations later in the disease course. Results: NFL and GFAP levels were elevated in MS patients as compared with control subjects (p < 0.001). The NFL levels were higher at relapses, whereas GFAP levels were unaffected. High NFL levels correlated with progression in patients with an active relapse (r = 0.49; p < 0.01) and in clinically stable patients (r = 0.29; p < 0.05). GFAP correlated to progression in the total patient cohort (r = 0.24; p < 0.05). Moreover, a strong correlation between NFL levels and inflammatory cell counts was evident in the group of patients with an ongoing relapse (r = 0.52; p = 0.001). Conclusions: CSF levels of neurofilament light and glial fibrillary acidic protein may have prognostic value in multiple sclerosis.

Relapsing-remitting multiple sclerosis has a variable prognosis and lacks a reliable laboratory prognostic marker. Our aim in this study was to investigate the association between neurofilament light levels in cerebrospinal fluid in early multiple sclerosis and disease severity at long-term follow-up. Neurofilament light levels in cerebrospinal fluid collected at diagnostic lumbar puncture were measured in 99 multiple sclerosis cases. Clinical data were obtained from 95 out of those at follow-up visits made 14 years (range 8—20 years) after disease onset. Significant correlations between neurofilament light levels and the multiple sclerosis severity score were found for all cases ( r = 0.30, p = 0.005), for relapsing-remitting multiple sclerosis cases ( r = 0.47, p < 0.001) and for cases with a recent relapse ( r = 0.60, p < 0.001). In the multivariate logistic regression analysis, neurofilament light levels >386 ng/L (median value of cases with detectable levels) increased the risk for severe multiple sclerosis fivefold (odds ratio 5.2, 95% confidence interval 1.8—15). Kaplan—Meier analysis showed that conversion to secondary-progressive multiple sclerosis was more likely in cases with neurofilament light levels >386 ng/L than in those with neurofilament light levels <60 ng/L ( p = 0.01) or 60—386 ng/L ( p = 0.03). We conclude that elevated levels of neurofilament light in cerebrospinal fluid collected at diagnostic lumbar puncture were associated with unfavourable prognosis. These data suggest that the neurofilament light level could be used as a prognostic marker in early relapsing-remitting multiple sclerosis.