Elevated mycobacterium avium subsp. paratuberculosis (MAP) antibody titer in Japanese multiple sclerosis

To investigate whether antibody production against mycobacterium avium subsp. paratuberculosis (MAP) is related to clinical characteristics of multiple sclerosis (MS) and human leukocyte antigen (HLA) alleles, IgG antibody against three MAP peptides and two human peptides homologous to MAP were measured in sera from 103 MS patients and 50 healthy controls (HCs). MS patients had higher IgG levels against MAP2694_295-303 (MAP2694-IgG) than HCs, while the other antibodies were comparable. Multivariate analysis demonstrated that higher MAP2694-IgG titers were associated with higher EDSS scores, but not with HLA alleles or dairy product consumption. Immune response against MAP may worsen MS disability.

Identifying the culprits in neurological autoimmune diseases

The target organ of neurological autoimmune diseases (NADs) is the central or peripheral nervous system. Multiple sclerosis (MS) is the most common NAD, whereas Guillain-Barré syndrome (GBS), myasthenia gravis (MG), and neuromyelitis optica (NMO) are less common NADs, but the incidence of these diseases has increased exponentially in the last few years. The identification of a specific culprit in NADs is challenging since a myriad of triggering factors interplay with each other to cause an autoimmune response. Among the factors that have been associated with NADs are genetic susceptibility, epigenetic mechanisms, and environmental factors such as infection, microbiota, vitamins, etc. This review focuses on the most studied culprits as well as the mechanisms used by these to trigger NADs.

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Neurological autoimmune diseases are caused by a complex interaction between genes, environmental factors, and epigenetic deregulation.

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Infectious agents can cause an autoimmune reaction to myelin epitopes through molecular mimicry and/or bystander activation.

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Gut microbiota dysbiosis contributes to neurological autoimmune diseases.

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Smoking increases the risk of NADs through inflammatory signaling pathways, oxidative stress, and Th17 differentiation.

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Deficiency in vitamin D favors NAD development through direct damage to the central and peripheral nervous system.

Once-daily glatiramer acetate decreases magnetic resonance imaging disease activity in Japanese patients with relapsing-remitting multiple sclerosis

OBJECTIVE

Multiple sclerosis (MS) prevalence, clinical patterns, and treatment responses vary between races and geographical latitudes. Glatiramer acetate (GA; Copaxone) has provided a safe, effective treatment option for relapsing-remitting MS patients in the USA, European nations, and other countries for decades. The objective of the present study was to assess the safety and efficacy of GA in reducing magnetic resonance imaging disease activity in Japanese patients with active relapsing-remitting MS.

METHODS

This phase 2, multicenter, open-label, single-arm, 52-week study measured the effect of GA 20 mg once-daily on magnetic resonance imaging disease activity. GA efficacy was evaluated through week 36, and safety through week 52. The primary end-point was change in the mean number of T₁-weighted gadolinium-enhancing (GdE) lesions from pretreatment (weeks -8, -4 and baseline) to weeks 28, 32 and 36. Secondary end-points included a change in mean number of new T₂-weighted lesions, GdE lesion and T₂ lesion volumes, annualized relapse rate, and Expanded Disability Status Scale scores.

RESULTS

GA therapy reduced the number of new GdE lesions by 65.66% (95% CI 33.19-82.35%). The number of new T₂ lesions and GdE lesion volume were also reduced from pretreatment. The annualized relapse rate was reduced by 42% compared with the 1 year before treatment. Changes in T₂ lesion volume and Expanded Disability Status Scale scores were favorable, but less pronounced. Most common adverse events were injection-site reactions.

CONCLUSIONS

The present study confirmed the well-established safety, tolerability and efficacy profile of GA in Japanese MS patients.

Copy number variations in multiple sclerosis and neuromyelitis optica

OBJECTIVE

To clarify the potential association of copy number variations (CNVs) with multiple sclerosis (MS) and neuromyelitis optica (NMO) in Japanese cases.

METHODS

Genome-wide association analyses of CNVs among 277 MS patients, 135 NMO/NMO spectrum disorder (NMOSD) patients, and 288 healthy individuals as a discovery cohort, and among 296 MS patients, 76 NMO/NMOSD patients, and 790 healthy individuals as a replication cohort were performed using high-density single nucleotide polymorphism microarrays.

RESULTS

A series of discovery and replication studies revealed that most identified CNVs were 5 to 50kb deletions at particular T cell receptor (TCR) gamma and alpha loci regions. Among these CNVs, a TCR gamma locus deletion was found in 16.40% of MS patients (p = 2.44E-40, odds ratio [OR] = 52.6), and deletion at the TCR alpha locus was found in 17.28% of MS patients (p = 1.70E-31, OR = 13.0) and 13.27% of NMO/NMOSD patients (p = 5.79E-20, OR = 54.6). These CNVs were observed in peripheral blood T-cell subsets only, suggesting the CNVs were somatically acquired. NMO/NMOSD patients carrying the CNV tended to be seronegative for anti-aquaporin-4 antibody or had significantly lower titers than those without CNV.

INTERPRETATION

Deletion-type CNVs at specific TCR loci regions contribute to MS and NMO susceptibility.