[Core data set for real world data in multiple sclerosis: customization for latin america from a global task force recommendation]. / Core data set para la generación de datos de la vida real en esclerosis múltiple: adaptación de una iniciativa global para América Latina.

INTRODUCTION: The primary objective of the core data set is to reduce heterogeneity and promote harmonization among data sources in EM, thereby reducing the time needed to execute real life data collection efforts. Recently, a group led by the Multiple Sclerosis Data Alliance has developed a core data set for collecting real-world data on multiple sclerosis (MS) globally. Our objective was to adapt this global data set to the needs of Latin America, so that it can be implemented by the registries already developed and in the process of development in the region. MATERIAL AND METHODS: A working group was formed regionally, the core data set created globally was adapted (translation process into Spanish, incorporation of regional variables and consensus on variables to be used). Consensus was obtained through the remote Delphi methodology of a round of questionnaires and remote discussion of the core data set variables. RESULTS: A total of 25 professionals from Latin America carried out the adaptation process between November 2022 and July 2023. Agreement was established on a core data set of nine categories and 45 variables, version 2023 to suggest its implementation in developed or developing registries, and MS cohorts in the region. CONCLUSION: The core data set seeks to harmonize the variables collected by registries and cohorts in MS in Latin America in order to facilitate said collection and allow collaboration between sources. Its implementation will facilitate real life data collection and collaboration in the region.

TITLE: Core data set para la generación de datos de la vida real en esclerosis múltiple: adaptación de una iniciativa global para América Latina.Introducción. Los objetivos primarios del core data set son reducir la heterogeneidad y promover la armonización entre las fuentes de datos en la esclerosis múltiple (EM), reduciendo así el tiempo necesario para ejecutar esfuerzos en la recolección de datos de vida real. Recientemente, un grupo liderado por la Multiple Sclerosis Data Alliance ha desarrollado un core data set para la recolección de datos del mundo real en EM a nivel global. Nuestro objetivo ha sido adaptar y consensuar este conjunto de datos globales a las necesidades de América Latina para que pueda ser implementado por los registros ya desarrollados y en proceso de desarrollo en la región. Material y métodos. Se conformó un grupo de trabajo regionalmente y se adaptó el core data set creado globalmente (proceso de traducción al español, incorporación de variables regionales y consenso sobre variables que se iban a utilizar). El consenso se obtuvo a través de la metodología Delphi remoto de ronda de cuestionarios y discusión a distancia de las variables del core data set. Resultados. Veinticinco profesionales de América Latina llevaron adelante el proceso de adaptación entre noviembre de 2022 y julio de 2023. Se estableció un acuerdo sobre un core data set de nueve categorías y 45 variables, versión 2023, con la sugerencia de implementarlo en registros desarrollados o en vías de desarrollo y cohortes de EM en la región. Conclusión. El core data set busca armonizar las variables recolectadas por los registros y las cohortes de EM en América Latina con el fin de facilitar dicha recolección y permitir una colaboración entre fuentes. Su implementación facilitará la recolección de datos de vida real y la colaboración en la región.

Comorbilidades en la esclerosis múltiple y su influencia en la elección del tratamiento / Comorbidities in multiple sclerosis and their influence on the choice of treatment

Los estudios clínicos de tratamientos para personas con esclerosis múltiple (pEM) se realizan en poblaciones seleccionadas, que excluyen a pacientes que presenten comorbilidades o medicaciones concomitantes. Sin embargo, un gran porcentaje de las pEM tiene alguna enfermedad adicional, que podría afectar a la respuesta y la elección del tratamiento. El objetivo de esta revisión es valorar cómo pueden las diferentes patologías concurrentes impactar en la elección de las terapias modificadoras de la enfermedad (TME) en las pEM. Se seleccionaron artículos relevantes mediante búsqueda en PubMed. Las comorbilidades se agruparon, a los fines de mejor ordenamiento de los artículos encontrados, en patologías diversas: autoinmunes, infecciones crónicas, cardiovasculares, respiratorias, metabólicas, oncológicas, neuropsiquiátricas y epilepsia. En cuanto a las patologías autoinmunes, es clave tener en cuenta los efectos de las TME sobre ellas y la posibilidad de interacción con sus tratamientos específicos. Las terapias inmunomoduladoras son seguras para personas con infecciones crónicas. Los tratamientos inmunosupresores, en general, están contraindicados en personas con infecciones activas. En las comorbilidades cardiovasculares y metabólicas deben tenerse en cuenta las potenciales reacciones de infusión asociadas a anticuerpos monoclonales, y los fenómenos asociados al inicio de tratamiento con moduladores del receptor de la esfingosina-1-fosfato. Las TME con efecto inmunosupresor están contraindicadas en personas con malignidades activas. Aunque la patología psiquiátrica de por sí no impide el uso de TME, debería tenerse precaución cuando aparecen nuevos síntomas psiquiátricos, y siempre tenerse en cuenta su monitorización y tratamiento. Por este motivo, entre los múltiples factores que deben considerarse a la hora de iniciar o cambiar una TME en pEM, las comorbilidades constituyen un elemento muchas veces decisivo.(AU)

Clinical trials of disease-modifying therapies (DMTs) for people with multiple sclerosis (pMS) are conducted in selected populations, excluding patients with comorbidities or concomitant medications. However, a large percentage of pMS have some additional disease, which could affect the response and choice of the DMT. The objective of this review is to assess how concurrent pathologies can impact the choice of DMTs. Relevant articles were selected through a systematic search in PubMed. Comorbidities were grouped for better classification into autoimmune, chronic infections, cardiovascular and metabolic, oncological and neuropsychiatric. In autoimmune pathologies, it is key to take into account the effects of TME on them and the possibility of interaction with their specific treatments. Immunomodulatory therapies are safe for people with chronic infections. Immunosuppressive treatments are generally contraindicated in people with active infections. In cardiovascular and metabolic comorbidities, infusion reactions associated with monoclonal antibodies, and the phenomena of starting treatment with S1P modulators, must be taken into account. DMTs with an immunosuppressive effect are contraindicated in people with active malignancies. Although psychiatric pathology per se does not preclude the use of DMTs, caution should be exercised when new psychiatric symptoms appear. For these reasons, among the multiple factors that must be considered when starting or changing a DMT in pMS, comorbidities constitute a decisive element.(AU)

[Comorbidities in multiple sclerosis and their influence on the choice of treatment]. / Comorbilidades en la esclerosis múltiple y su influencia en la elección del tratamiento.

Clinical trials of disease-modifying therapies (DMTs) for people with multiple sclerosis (pMS) are conducted in selected populations, excluding patients with comorbidities or concomitant medications. However, a large percentage of pMS have some additional disease, which could affect the response and choice of the DMT. The objective of this review is to assess how concurrent pathologies can impact the choice of DMTs. Relevant articles were selected through a systematic search in PubMed. Comorbidities were grouped for better classification into autoimmune, chronic infections, cardiovascular and metabolic, oncological and neuropsychiatric. In autoimmune pathologies, it is key to take into account the effects of TME on them and the possibility of interaction with their specific treatments. Immunomodulatory therapies are safe for people with chronic infections. Immunosuppressive treatments are generally contraindicated in people with active infections. In cardiovascular and metabolic comorbidities, infusion reactions associated with monoclonal antibodies, and the phenomena of starting treatment with S1P modulators, must be taken into account. DMTs with an immunosuppressive effect are contraindicated in people with active malignancies. Although psychiatric pathology per se does not preclude the use of DMTs, caution should be exercised when new psychiatric symptoms appear. For these reasons, among the multiple factors that must be considered when starting or changing a DMT in pMS, comorbidities constitute a decisive element.

TITLE: Comorbilidades en la esclerosis múltiple y su influencia en la elección del tratamiento.Los estudios clínicos de tratamientos para personas con esclerosis múltiple (pEM) se realizan en poblaciones seleccionadas, que excluyen a pacientes que presenten comorbilidades o medicaciones concomitantes. Sin embargo, un gran porcentaje de las pEM tiene alguna enfermedad adicional, que podría afectar a la respuesta y la elección del tratamiento. El objetivo de esta revisión es valorar cómo pueden las diferentes patologías concurrentes impactar en la elección de las terapias modificadoras de la enfermedad (TME) en las pEM. Se seleccionaron artículos relevantes mediante búsqueda en PubMed. Las comorbilidades se agruparon, a los fines de mejor ordenamiento de los artículos encontrados, en patologías diversas: autoinmunes, infecciones crónicas, cardiovasculares, respiratorias, metabólicas, oncológicas, neuropsiquiátricas y epilepsia. En cuanto a las patologías autoinmunes, es clave tener en cuenta los efectos de las TME sobre ellas y la posibilidad de interacción con sus tratamientos específicos. Las terapias inmunomoduladoras son seguras para personas con infecciones crónicas. Los tratamientos inmunosupresores, en general, están contraindicados en personas con infecciones activas. En las comorbilidades cardiovasculares y metabólicas deben tenerse en cuenta las potenciales reacciones de infusión asociadas a anticuerpos monoclonales, y los fenómenos asociados al inicio de tratamiento con moduladores del receptor de la esfingosina-1-fosfato. Las TME con efecto inmunosupresor están contraindicadas en personas con malignidades activas. Aunque la patología psiquiátrica de por sí no impide el uso de TME, debería tenerse precaución cuando aparecen nuevos síntomas psiquiátricos, y siempre tenerse en cuenta su monitorización y tratamiento. Por este motivo, entre los múltiples factores que deben considerarse a la hora de iniciar o cambiar una TME en pEM, las comorbilidades constituyen un elemento muchas veces decisivo.

Microglia-derived extracellular vesicles in homeostasis and demyelination/remyelination processes.

Microglia (MG) play a crucial role as the predominant myeloid cells in the central nervous system and are commonly activated in multiple sclerosis. They perform essential functions under normal conditions, such as actively surveying the surrounding parenchyma, facilitating synaptic remodeling, engulfing dead cells and debris, and protecting the brain against infectious pathogens and harmful self-proteins. Extracellular vesicles (EVs) are diverse structures enclosed by a lipid bilayer that originate from intracellular endocytic trafficking or the plasma membrane. They are released by cells into the extracellular space and can be found in various bodily fluids. EVs have recently emerged as a communication mechanism between cells, enabling the transfer of functional proteins, lipids, different RNA species, and even fragments of DNA from donor cells. MG act as both source and recipient of EVs. Consequently, MG-derived EVs are involved in regulating synapse development and maintaining homeostasis. These EVs also directly influence astrocytes, significantly increasing the release of inflammatory cytokines like IL-1ß, IL-6, and TNF-α, resulting in a robust inflammatory response. Furthermore, EVs derived from inflammatory MG have been found to inhibit remyelination, whereas Evs produced by pro-regenerative MG effectively promote myelin repair. This review aims to provide an overview of the current understanding of MG-derived Evs, their impact on neighboring cells, and the cellular microenvironment in normal conditions and pathological states, specifically focusing on demyelination and remyelination processes.

Therapeutic plasma exchange in MS refractory relapses: Long-term outcome.

INTRODUCTION: Therapeutic plasma exchange (TPE) is considered a treatment option for steroid-refractory multiple sclerosis (MS) relapses. Our objective was to assess long-term clinical response to TPE in MS steroid-refractory exacerbations. METHODS: Retrospective study of relapsing remitting MS (RRMS) patients presenting intravenous methylprednisolone (IVMPS)-refractory relapses, who underwent TPE. Response to TPE was assessed at 1, 3, 6, 12 and 24-months post-treatment, and compared to a second group of RRMS patients with similar demographic and clinical characteristics presenting, IVMPS-refractory relapses but not treated with TPE. Multivariate regression analysis was used to assess potential predictors of significant clinical response. RESULTS: Between 2011 to 2020, a total of 23 RRMS patients were treated with TPE. Twenty-one patients not receiving the treatment served as controls. No differences in demographic or clinical characteristics, or predictors of clinical improvement after TPE were detected between groups. Seventy-eight percent of patients treated with TPE presented clinical improvement at 24 months. TPE-treated patients presented lower EDSS scores at 6 and at 24 months. Younger age, presence of gadolinium-enhancing lesions and TPE treatment were associated with better clinical outcomes. No life-threatening side effects were reported. CONCLUSIONS: TPE is a safe and well tolerated procedure that decreases long-term disability in RRMS patients with IVMPS-refractory relapses.

Iron Metabolism in Oligodendrocytes and Astrocytes, Implications for Myelination and Remyelination.

Iron is a key nutrient for normal central nervous system (CNS) development and function; thus, iron deficiency as well as iron excess may result in harmful effects in the CNS. Oligodendrocytes and astrocytes are crucial players in brain iron equilibrium. However, the mechanisms of iron uptake, storage, and efflux in oligodendrocytes and astrocytes during CNS development or under pathological situations such as demyelination are not completely understood. In the CNS, iron is directly required for myelin production as a cofactor for enzymes involved in ATP, cholesterol and lipid synthesis, and oligodendrocytes are the cells with the highest iron levels in the brain which is linked to their elevated metabolic needs associated with the process of myelination. Unlike oligodendrocytes, astrocytes do not have a high metabolic requirement for iron. However, these cells are in close contact with blood vessel and have a strong iron transport capacity. In several pathological situations, changes in iron homoeostasis result in altered cellular iron distribution and accumulation and oxidative stress. In inflammatory demyelinating diseases such as multiple sclerosis, reactive astrocytes accumulate iron and upregulate iron efflux and influx molecules, which suggest that they are outfitted to take up and safely recycle iron. In this review, we will discuss the participation of oligodendrocytes and astrocytes in CNS iron homeostasis. Understanding the molecular mechanisms of iron uptake, storage, and efflux in oligodendrocytes and astrocytes is necessary for planning effective strategies for iron management during CNS development as well as for the treatment of demyelinating diseases.

Differential diagnosis in acute inflammatory myelitis.

INTRODUCTION: Establishing differential diagnosis between different inflammatory causes of acute transverse myelitis (ATM) can be difficult. The objective of this study was to see which clinical, imaging or laboratory findings best contribute to confirm ATM etiology. METHODS: We reviewed clinical history, MRI images, CSF and serum laboratory tests in a retrospective study of patients presenting ATM. Univariate and multivariate multinomial logistic regression analysis was performed for each of the items listed above. RESULTS: One hundred and seventy-two patients were analyzed in the study: 68 with multiple sclerosis (MS), 67 presenting idiopathic myelitis (IM; 23 of which were recurrent), 21 who developed positive systemic-antibodies associated myelitis (SAb-M) and 16 with neuromyelitis optica spectrum disorders (NMOSD). The following factors were associated with increased risk of developing MS: lower values in the modified Rankin scale at admission; positive oligoclonal bands (OCB); higher spinal cord lesion load; presence of brain demyelinating lesions; and disease recurrence. Longitudinally extended (LE) lesions, brain demyelinating lesions, and recurrences also contributed to final diagnosis of NMOSD. Multivariate multinomial logistic regression analysis showed presence of LE lesions increased risk of NMOSD and recurrence of ATM. Whereas, brain demyelinating lesions, and presence of OCB increased risk of MS. CONCLUSIONS: ATM etiology may be clarified on the basis of spinal cord and brain MRI findings, together with CSF biochemistry and serum laboratory test results, allowing more timely and exact diagnosis as well as specific therapy for cases of uncertain origin.

SWAN-Venule: An Optimized MRI Technique to Detect the Central Vein Sign in MS Plaques.

BACKGROUND AND PURPOSE: Multiple sclerosis lesions develop around small veins that are radiologically described as the so-called central vein sign. With 7T MR imaging and magnetic susceptibility-based sequences, the central vein sign has been observed in 80%-100% of MS lesions in patients' brains. However, a lower proportion ∼50% has been reported at 3T using susceptibility-weighted angiography (SWAN). Our aim was to assess a modified version of SWAN optimized at 3T for sensitive detection of the central vein sign. MATERIALS AND METHODS: Thirty subjects with MS were scanned on a 3T clinical MR imaging system. 3D T2-weighted FLAIR and optimized 3D SWAN called SWAN-venule, were acquired after injection of a gadolinium-based contrast agent. Patients showing >3 focal white matter lesions were included. The central vein sign was recorded by 2 trained raters on SWAN-venule images in the supratentorial brain. RESULTS: Twenty patients showing >3 white matter lesions were included. A total of 380 white matter lesions (135 periventricular, 144 deep white matter, and 101 juxtacortical) seen on both FLAIR and SWAN-venule images were analyzed. Overall, the central vein sign was detected in 86% of the white matter lesions (periventricular, 89%; deep white matter, 95%; and juxtacortical, 78%). CONCLUSIONS: The SWAN-venule technique is an optimized MR imaging sequence for highly sensitive detection of the central vein sign in MS brain lesions. This work will facilitate the validation and integration of the central vein sign to increase the diagnostic certainty of MS and further prevent misdiagnosis in clinical practice.

Disease activity impacts disability progression in primary progressive multiple sclerosis.

BACKGROUND: Although solid information on the natural history of primary progressive multiple sclerosis (PPMS) is available, evidence regarding impact of disease activity on PPMS progression remains controversial. OBJECTIVE: To describe the clinical characteristics, presence or absence of MRI activity, and natural history of a PPMS cohort from two referral centers in Argentina and assess whether clinical and/or radiological disease activity correlated with disability worsening. METHODS: Retrospective study conducted at two MS clinics in Buenos Aires, Argentina, through comparative analysis of patients with and without evidence of disease activity. RESULTS: Clinical and/or radiologic activity was presented in 56 (31%) of 178 patients. When stratified by age at onset, we found that for every 10 years of increase in age at onset, risk of reaching EDSS scores of 4 and 6 increased by 26% and 31%, respectively (EDSS 4: HR 1.26, CI 95%: 1.06-1.50; EDSS 6: HR 1.31, CI 95%: 1.06-1.62). Patients who presented clinical exacerbations reached EDSS scores of 6, 7 and 8 faster than those without associated exacerbations (p = 0.009, p = 0.016 and p = 0.001, respectively). Likewise, patients who presented gadolinium-enhancing lesions during the course of disease reached EDSS scores of 7 earlier (p = 0.002). CONCLUSION: Older age at onset and presence of clinical and/or radiological disease activity correlated with accelerated disability progression in this cohort of PPMS patients.

Clinical and imaging features distinguishing Susac syndrome from primary angiitis of the central nervous system.

INTRODUCTION: To assess clinical and/or imaging features useful to distinguish between Susac syndrome (SuS) and primary angiitis of central nervous system (PACNS). METHODS: Multicenter retrospective analysis of two cohorts of Argentine patients diagnosed with SuS and PACNS. RESULTS: 13 patients diagnosed with SuS (6 women and 7 men, mean age 35 ±â€¯10 years) and 15 with PACNS (10 women and 5 men, mean age 44 ±â€¯18 years) were analyzed. Cognitive impairment (11 out of 13 patients vs. 5 out of 15, p = .006), ataxia (7 out of 13 vs. 2 out of 15, p = .042) and auditory disturbances (7 out of 13 vs. 0 out of 15, p = .003) were more frequent in SuS patients; whereas seizures were more frequent in PACNS patients (8 out of 15 vs. 1 out of 13, p = .035). On MRI, corpus callosum (CC) involvement was observed more often in SuS, with abnormalities in CC genu, in 13 out of 13 SuS patients vs. only 2 out of 15 PACNS patients (p < .001); in CC body these were present in 13 out of 13 SuS patients vs. 1 out of 15 PACNS patients, (p < .001); and in CC splenium in 12 out of 13 Sus patients vs. 1 of 15 PACNS, p < .001). Cortical lesions were more frequent in PACNS patients (10 out of 15 vs. 3 out of 13 SuS patients, p = .02), as were hemorrhages (5 out of 15 vs. 0 out of 13 SuS, p = .04) and multiple basal ganglia infarcts (7 out of 15 vs. 1 out of 13 Sus, p = .037). CONCLUSION: Specific clinical and/or MRI findings may help distinguish SuS from PACNS with potential therapeutic implications.

Brain and spinal cord lesion criteria distinguishes AQP4-positive neuromyelitis optica and MOG-positive disease from multiple sclerosis.

OBJECTIVE: Test the ability of a brain and spinal cord MRI criteria to differentiate neuromyelitis optica spectrum disorders and MOG-disease from MS. MRI criteria was further tested in patients with CIS and pediatric MS. BACKGROUND: MOG-disease and neuromyelitis optica spectrum disorders can present clinical and radiological features strikingly similar to those of MS. Previously, diagnostic criteria based on brain MRI have been proposed to distinguish between these demyelinating diseases (Matthews-Jurynczik criteria), but spinal cord imaging and its relevance in CIS have not been evaluated. Simple brain and spinal cord MRI criteria may help separate these three inflammatory CNS diseases both in adults and children, aiding in early diagnostic decision-making, such as need for antibody testing. DESIGN/METHODS: We included 150 participants (23 with aquaporin-4-positive neuromyelitis optica spectrum disorder, 14 with MOG-disease, 20 with aquaporin-4-negative neuromyelitis optica spectrum disorder, 48 with adult-onset relapsing remitting MS, 24 with pediatric-onset MS and 21 with clinically isolated syndrome). Brain and spinal cord MRI scans were anonymised and scored by 2 separate raters, based on two sets of criteria: one previously described by Matthews and colleagues (including presence of at least one lesion adjacent to the body of lateral ventricle and in the inferior temporal lobe, or presence of subcortical U-fiber lesion or a Dawson's finger-type lesion), and an extended version including spinal cord features (non-longitudinally extensive cervical lesion). RESULTS: Extended MRI brain and spinal cord lesion criteria were able to separate adult-onset relapsing remitting MS with 100% sensitivity and 87% specificity from aquaporin-4-positive neuromyelitis optica spectrum disorder; and with 100% sensitivity and 79% specificity from MOG-disease. Additionally, brain and spinal cord criteria showed 100% sensitivity and specificity in patients presenting optic neuritis. Brain and spinal cord criteria were less sensitive in patients with CIS and in pediatric MS patients. CONCLUSIONS: Our data suggest radiological criteria can be useful to separate MS from MOG- and aquaporin-4-positive neuromyelitis optica spectrum disorders, in particular in patients with optic neuritis. Further work is needed to support their use in CIS.

Evolution of multiple sclerosis prevalence and phenotype in Latin America.

BACKGROUND: Literature regarding MS epidemiology and phenotype is scarce but has increased markedly over the past years. The objective of the present work is to assess the evolution of the prevalence and phenotype of MS in Latin America during recent years. METHODS: Review of literature. RESULTS: MS prevalence levels are low to medium in Latin America, although these have increased in recent years. A small latitudinal gradient has also been observed, but exceptions to this rule exist, suggesting other genetic and environmental factors ultimately influence regional prevalence rates. One of the distinctive features of the region is the complex genetic admixture arising from multiple divergent population ancestries in different countries including: Native Americans, Caucasians and Africans. Another variable which would lower MS risk in the region could be a protective effect linked to exposure to certain infections, such as parasites. Despite differences in MS epidemiology, Latin American patients show an MS phenotype very similar to that of Caucasian patients, and a progressively increasing female gender ratio as has been described worldwide. CONCLUSION: MS epidemiology in Latin American patients has distinctive features. Both, prevalence and incidence, are increasing.

Gender ratio trends over time in multiple sclerosis patients from Argentina.

Several studies in multiple sclerosis (MS) suggest a trend of increasing disease frequency in women during the last decades. A direct comparison of gender ratio trends among MS populations from Argentina remains to be carried out. The objective of the study was to compare gender ratio trends, over a 50-year span in MS populations from Argentina. METHODS: multicenter study that included patients from 14 MS Centers of Argentina. Patients with definite MS with birth years ranging from 1940 to 1989 were included. Gender ratios were calculated by five decades based on year of birth and were adjusted for the F/M born-alive ratio derived from the Argentinean national registry of births. The F/M ratios were calculated using a multivariate logistic regression per five decades by the year of birth approach. Analyses were performed using Stata 10.1. RESULTS: 1069 patients were included. Gender ratios showed a significant increase from the first to the last decade in the whole MS sample (from 1.8 to 2.7; p value for trend=0.023). The Gender ratio did not show differences considering MS subtype. CONCLUSION: our study showed a modest increase of the F/M ratio (from 1.8 to 2.7) over time among patients affected by MS in Argentina.

Increasing prevalence of multiple sclerosis in Buenos Aires, Argentina.

UNLABELLED: In 1996, the prevalence of multiple sclerosis (MS) for the metropolitan area of Buenos Aires using the capture-recapture method was estimated to be between 14 and 19.8 cases per 100,000 inhabitants. The aim of this study was to update the prevalence to 2014 following the same methodology. METHODS: Gran Buenos Aires is the denomination that refers to the megalopolis comprised by the autonomous city of Buenos Aires and the surrounding conurbation of the province of Buenos Aires. The study was carried out taking December 2014 as the prevalence month. We used the capture-recapture method to estimate the prevalence of MS cross-matching registries from 6 MS Centers from the metropolitan area of Buenos Aires. Log-linear model Poisson regression was used to estimate the number of affected MS patients not detected by any of the 6 sources considered. RESULTS: 1035 registries were obtained from the 6 lists from 910 different patients detected. The population of the area based on 2010 census was 12,806,866, the number of MS cases estimated amongst source interactions were 4901. The estimated prevalence was 38.2 per 100,000 inhabitants (95% CI 36.1-41.2). CONCLUSION: The study is an update almost 20 years after the first one in the area showing a significant increase in the previous reported prevalence. Our findings are in line with previous studies performed in other regions of the world.

Combined effects of transferrin and thyroid hormone during oligodendrogenesis In vitro.

Thyroid hormones (THs) and transferrin (Tf) are factors capable of favoring myelination due to their positive effects on oligodendroglial cell (OLG) differentiation. The first notion of a combined effect of apotransferrin (aTf) and TH emerged from experiments conducted in young hyperthyroid animals, which showed a seven-fold increase in the expression of Tf mRNA and precocious myelination when compared with control animals. The mechanism underlying this phenomenon in young hyperthyroid rats could consist of an increase in Tf synthesis, which in the CNS is almost exclusively produced by OLG. Overall, our results show that, during the initial stages of OLG differentiation, Tf synthesis triggers thyroid hormone receptor alpha 1 (TRα1) expression in the subventricular zone (SVZ) and promotes proliferating cells to become responsive to this trophic factor. Exposure to TH could then regulate Tf expression through TRα1 and promote the induction of thyroid hormone receptor beta (TRß) expression, which mediates TH effects on myelination through the activation of final OLG differentiation. This regulation of the combined effects of Tf and THs implies that both factors are fundamental actors during oligodendrogenesis. GLIA 2016;64:1879-1891.

Disease onset in familial and sporadic multiple sclerosis in Argentina.

UNLABELLED: The present study was carried out to assess if there is an anticipation of age at onset in younger generations of familial multiple sclerosis (FMS) vs. sporadic MS (SMS) in Argentina. METHODS: multicenter study that included patients from 14 MS Centers of Argentina. Patients were considered as FMS if they had in their family at least one relative of first or second degree diagnosed with MS; otherwise, patients were considered to have SMS. We compared the age at onset between familial and sporadic cases as well as the age at onset between relatives from different generations in FMS vs. SMS. RESULTS: 1333 patients were included, 97 of them were FMS (7.3%). A lower age at onset in the younger generations of FMS cases was found compared with older generations of FMS as well as. SMS cases (24.1±3.7 years vs. 30.3±5.7 years, and 32.4±9.4 respectively; p<0.001). No differences were observed between older generations of FMS vs. SMS cases (p=0.12). CONCLUSION: we observed an anticipation of age at onset of MS in younger generations of patients with FMS vs. older generations of FMS and SMS.

Multiple sclerosis and environmental factors: the role of vitamin D, parasites, and Epstein-Barr virus infection.

Pathogenic mechanisms underlying multiple sclerosis development have yet to be clearly identified, but considerable evidence indicates that autoimmunity plays an important role in the etiology of the disease. It is generally accepted that autoimmune diseases like MS arise from complex interactions between genetic susceptibility and environmental factors. Although environmental factors unequivocally influencing MS development have yet to be established, accumulating evidence singles out several candidates, including sunlight-UV exposure or vitamin D deficiency, viral infections, hygiene, and cigarette smoking. Vitamin D deficiency has been associated with different autoimmune diseases. Several investigations indicate 125 (OH)2 vitamin D plays a critical role in shaping T-cell response and inducing T cells with immunosuppressive properties. Likewise, helminth infections represent another potential environmental factor exerting immunomodulatory properties. Both epidemiological and experimental data provide evidence to support autoimmune down-regulation secondary to parasite infections in patients with MS, through regulatory T- and B-cell action, with effects extending beyond simple response to an infectious agent. Finally, different epidemiological studies have demonstrated that Epstein-Barr virus infection confers added risk of developing MS. Proposed mechanisms responsible for this association include activation and expansion of self-reactive T and B cells, lower threshold for self-tolerance breakdown, and enhanced autoreactive B-cell survival, all to be discussed in this review. Understanding environmental factors influencing propensity to MS will lead to new and more effective approaches to prevent and treat the disease.