Puberty in females enhances the risk of an outcome of multiple sclerosis in children and the development of central nervous system autoimmunity in mice.

BACKGROUND: For reasons that remain unclear, three times more women develop multiple sclerosis (MS) than men. This preponderance among women is evident only after 12 years of age, implicating pubertal factors in the risk of MS. OBJECTIVE: To investigate the influence of female puberty on central nervous system (CNS) autoimmunity. METHODS: We examined the relationship between age of menarche on MS outcomes in 116 female children (< 16 years old) whom presented with incident 'acquired demyelinating syndromes' (ADS) and were followed prospectively in the national Canadian Pediatric Demyelinating Disease Study, from 2004-2013. Furthermore, we directly investigated the effects of puberty on susceptibility to experimental autoimmune encephalomyelitis (EAE) in two groups of female mice that differed only in their pubertal status. RESULTS: In the ADS children, a later age of menarche was associated with a decreased risk of subsequent MS diagnosis. This relationship persisted, after accounting for patient age at ADS presentation and the presence of ≥1 T2 lesions on brain magnetic resonance imaging (MRI), with a hazard ratio (HR) of 0.64; and additional factors that associate with MS outcomes in ADS children, including low vitamin D levels. Furthermore, we found female mice that had transitioned through puberty were more susceptible to EAE than age-matched, pre-pubertal mice. CONCLUSION: Puberty in females enhances CNS autoimmune mechanisms that lead to MS in humans and EAE in mice.

Early-onset dementias: diagnostic and etiological considerations.

This paper summarizes the body of literature about early-onset dementia (EOD) that led to recommendations from the Fourth Canadian Consensus Conference on the Diagnosis and Treatment of Dementia. A broader differential diagnosis is required for EOD compared with late-onset dementia. Delays in diagnosis are common, and the social impact of EOD requires special care teams. The etiologies underlying EOD syndromes should take into account family history and comorbid diseases, such as cerebrovascular risk factors, that may influence the clinical presentation and age at onset. For example, although many EODs are more likely to have Mendelian genetic and/or metabolic causes, the presence of comorbidities may drive the individual at risk for late-onset dementia to manifest the symptoms at an earlier age, which contributes further to the observed heterogeneity and may confound diagnostic investigation. A personalized medicine approach to diagnosis should therefore be considered depending on the age at onset, clinical presentation, and comorbidities. Genetic counseling and testing as well as specialized biochemical screening are often required, especially in those under the age of 40 and in those with a family history of autosomal dominant or recessive disease. Novel treatments in the drug development pipeline for EOD, such as genetic forms of Alzheimer's disease, should target the specific pathogenic cascade implicated by the mutation or biochemical defect.

A role for VAV1 in experimental autoimmune encephalomyelitis and multiple sclerosis.

Multiple sclerosis, the most common cause of progressive neurological disability in young adults, is a chronic inflammatory disease. There is solid evidence for a genetic influence in multiple sclerosis, and deciphering the causative genes could reveal key pathways influencing the disease. A genome region on rat chromosome 9 regulates experimental autoimmune encephalomyelitis, a model for multiple sclerosis. Using interval-specific congenic rat lines and association of single-nucleotide polymorphisms with inflammatory phenotypes, we localized the gene of influence to Vav1, which codes for a signal-transducing protein in leukocytes. Analysis of seven human cohorts (12,735 individuals) demonstrated an association of rs2546133-rs2617822 haplotypes in the first VAV1 intron with multiple sclerosis (CA: odds ratio, 1.18; CG: odds ratio, 0.86; TG: odds ratio, 0.90). The risk CA haplotype also predisposed for higher VAV1 messenger RNA expression. VAV1 expression was increased in individuals with multiple sclerosis and correlated with tumor necrosis factor and interferon-gamma expression in peripheral blood and cerebrospinal fluid cells. We conclude that VAV1 plays a central role in controlling central nervous system immune-mediated disease and proinflammatory cytokine production critical for disease pathogenesis.