Intrathecal IgM production is a strong risk factor for early conversion to multiple sclerosis.

OBJECTIVES: To evaluate intrathecal immunoglobulin M (IgM) production, as compared to previously established risk factors, as risk factor for conversion from clinically isolated syndrome (CIS) to multiple sclerosis (MS) and to explore the association of intrathecal IgM production with onset age and radiologic and CSF findings in CIS/early MS. METHODS: Comprehensive CSF data, including oligoclonal immunoglobulin G (IgG) bands (OCB) and calculated intrathecal IgM and IgG production, were collected in a prospective study of 150 patients with CIS/early MS with regular clinical and MRI assessments. RESULTS: Intrathecal IgM production >0% occurred in 23.2% (33/142) of patients, who were on average 5 years younger at disease onset (p = 0.013) and more frequently had infratentorial lesions (18/32, 56.3%) than patients without intrathecal IgM production (33/104, 31.7%, p = 0.021). In multivariable Cox regression analyses, intrathecal IgM production in patients with a CIS (n = 93, median clinical and MRI follow-up 24 and 21 months) was strongly associated with conversion to MS according to the McDonald 2010 criteria (hazard ratio [95% confidence interval] 3.05 [1.45-6.44], p = 0.003) after adjustment for age (0.96 [0.93-1.00], p = 0.059), OCB (0.92 [0.33-2.61], p = 0.879), intrathecal IgG production (0.98 [0.48-1.99], p = 0.947), and radiologic evidence of dissemination in space (2.63 [1.11-6.22], p = 0.028). CONCLUSION: Intrathecal IgM production is a strong independent risk factor for early conversion to MS and may thus represent a clinically meaningful marker for predicting future disease activity in patients with a CIS.

Next-generation sequencing identifies altered whole blood microRNAs in neuromyelitis optica spectrum disorder which may permit discrimination from multiple sclerosis.

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) have a similar clinical phenotype but represent distinct diseases, requiring different therapies. MicroRNAs (miRNAs) are short non-coding RNAs whose expression profiles can serve as diagnostic biomarkers and which may be involved in the pathophysiology of neuroinflammatory diseases. Here, we analyzed miRNA profiles in serum and whole blood of patients with NMOSD and clinically isolated syndrome (CIS)/relapsing-remitting MS (RRMS) as well as healthy controls by next-generation sequencing (NGS). METHODS: MiRNA expression profiles were determined by NGS in sera of patients with aquaporin-4 antibody-positive NMOSD (n = 20), CIS/RRMS (n = 20), and healthy controls (n = 20) and in whole blood of patients with NMOSD (n = 11), CIS/RRMS (n = 60), and healthy controls (n = 43). Differentially expressed miRNAs were calculated by analysis of variance and t tests. All significance values were corrected for multiple testing. Selected miRNAs were validated in whole blood of patients with NMOSD (n = 18) and CIS/RRMS (n = 19) by quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: None of 261 miRNAs detected in serum but 178 of 416 miRNAs detected in whole blood showed significantly different expression levels among the three groups. Pairwise comparisons revealed 115 (NMOSD vs. CIS/RRMS), 141 (NMOSD vs. healthy controls), and 44 (CIS/RRMS vs. healthy controls) miRNAs in whole blood with significantly different expression levels. qRT-PCR confirmed different expression levels in whole blood of patients with NMOSD and CIS/RRMS for 9 out of 10 exemplarily chosen miRNAs. In silico enrichment analysis demonstrated an accumulation of altered miRNAs in NMOSD in particular in CD15(+) cells (i.e., neutrophils and eosinophils). CONCLUSIONS: This study identifies a set of miRNAs in whole blood, which may have the potential to discriminate NMOSD from CIS/RRMS and healthy controls. In contrast, miRNA profiles in serum do not appear to be promising diagnostic biomarkers for NMOSD. Enrichment of altered miRNAs in CD15(+) neutrophils and eosinophils, which were previously implicated in the pathophysiology of NMOSD, suggests that miRNAs could be involved in the regulation of these cells in NMOSD.

Tracking CNS and systemic sources of oxidative stress during the course of chronic neuroinflammation.

The functional dynamics and cellular sources of oxidative stress are central to understanding MS pathogenesis but remain elusive, due to the lack of appropriate detection methods. Here we employ NAD(P)H fluorescence lifetime imaging to detect functional NADPH oxidases (NOX enzymes) in vivo to identify inflammatory monocytes, activated microglia, and astrocytes expressing NOX1 as major cellular sources of oxidative stress in the central nervous system of mice affected by experimental autoimmune encephalomyelitis (EAE). This directly affects neuronal function in vivo, indicated by sustained elevated neuronal calcium. The systemic involvement of oxidative stress is mirrored by overactivation of NOX enzymes in peripheral CD11b(+) cells in later phases of both MS and EAE. This effect is antagonized by systemic intake of the NOX inhibitor and anti-oxidant epigallocatechin-3-gallate. Together, this persistent hyper-activation of oxidative enzymes suggests an "oxidative stress memory" both in the periphery and CNS compartments, in chronic neuroinflammation.

Association of serum Epstein-Barr nuclear antigen-1 antibodies and intrathecal immunoglobulin synthesis in early multiple sclerosis.

Multiple sclerosis (MS) is associated with Epstein-Barr virus (EBV) infection. A characteristic feature of MS is an intrathecal synthesis of immunoglobulin (Ig)G. In 90 patients with clinically isolated syndromes/early relapsing-remitting MS, serum antibodies to Epstein-Barr nuclear antigen-1, but not to EBV viral capsid antigen, rubella, or varicella zoster virus, were higher (p=0.03) in those with than those without a calculated intrathecal IgG synthesis >0% and correlated with the percentage (r=0.27, p=0.009) and concentration (r=0.27, p=0.012) of intrathecally produced IgG. These findings suggest a link between EBV infection and the events leading to intrathecal IgG synthesis in patients with MS.