Neuromyelitis optica (NMO), also known as Devic's disease, is an autoimmune, inflammatory disorder of the central nervous system (CNS) in which the immune system attacks myelin of the neurons located at the optic nerves and spinal cord, thus producing a simultaneous or sequential optic neuritis and myelitis. The objective of this study was evaluated the background T-cell function of patients suffering from neuromyelitis optica (NMO), an autoimmune disorder of the central nervous system. In our study, the in vitro T cell proliferation and the production of Th1 cytokines were significantly lower in cell cultures from NMO patients, as compared with healthy individuals. In contrast, a dominant Th17-like phenotype, associate with higher IL-23 and IL-6 production by LPS-activated monocytes, was observed among NMO patients. The release of IL-21 and IL-6 by polyclonally activated CD4+ T cells was directly correlated to neurological disability. In addition, the in vitro release of IL-21, IL-6 and IL-17 was significantly more resistant to glucocorticoid inhibition in NMO patients. In conclusion, the results indicate dominant Th17-related response in NMO patients that was directly proportional to neurological disability. Furthermore, our results can help to explain why NMO patients trend to be more refractory to corticoid treatment.

Evaluation of VEP in patients with definite NMO revealed a pattern that is different from that of MS in 81.6% of eyes examined, characterized by the absence of responses, or decreased amplitude with normal latency.

SummaryT helper type 17 (Th17) cytokines have been implicated in the pathogenesis of neuromyelitis optica (NMO). As humanized anti-interleukin (IL)-6R (tocilizumab) immunoglobulin (Ig)G has been used as disease-modifying therapy for NMO, the objective of our study was to investigate the role of endogenous IL-6 on NMO-derived CD4 1 T cell behaviour. High production of IL-6, IL-17 and IL-21 by CD4 1 T-cells was detected in NMO patients.Further, IL-21 and IL-6 levels were related directly to the level of neurological disabilities. The addition of anti-IL-6R IgG not only reduced directly the production of these cytokines, but also almost abolished the ability of activated autologous monocytes in enhancing IL-6, IL-17 and IL-21 release by CD4 1 T cells. In contrast, the production of IL-10 was amplified in those cell cultures. Further, anti-IL-6R monoclonal antibodies (mAb) also potentiated the ability of glucocorticoid in reducing Th17 cytokines. Finally, the in-vivo and in-vitro IL-6 levels were significantly higher among those patients who experienced clinical relapse during 2-year follow-up. In summary, our results suggest a deleterious role of IL-6 in NMO by favouring, at least in part, the expansion of corticoid-resistant Th17 cells.

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We studied the allelic profile of CAG and CCG repeats in 61 Brazilian individuals in 21 independent families affected by Huntington's disease (HD). Thirteen individuals had two normal alleles for HD, two had one mutable normal allele and no HD phenotype, and forty-six patients carried at least one expanded CAG repeat allele. Forty-five of these individuals had one expanded allele and one individual had one mutable normal allele (27 CAG repeats) and one expanded allele (48 CAG repeats). Eleven of these forty-five subjects had a mutant allele with reduced penetrance, and thirty-four patients had a mutant allele with complete penetrance. Inter-and intragenerational investigations of CAG repeats were also performed. We found a negative correlation between the number of CAG repeats and the age of disease onset (r ¼ À0.84; Po0.001) and no correlation between the number of CCG repeats and the age of disease onset (r ¼ 0.06). We found 40 different haplotypes and the analysis showed that (CCG) 10 was linked to a CAG normal allele in 19 haplotypes and to expanded alleles in two haplotypes. We found that (CCG) 7 was linked to expanded CAG repeats in 40 haplotypes (95.24%) and (CCG) 10 was linked to expanded CAG repeats in only two haplotypes (4.76%). Therefore, (CCG) 7 was the most common allele in HD chromosomes in this Brazilian sample. It was also observed that there was a significant association of (CCG) 7 with the expanded CAG alleles (v 2 ¼ 6.97, P ¼ 0.0084). Worldwide, the most common CCG alleles have 7 or 10 repeats. In Western Europe, (CCG) 7 is the most frequent allele, similarly to our findings.