Controversies in neuroimmunology: multiple sclerosis, vaccination, SARS-CoV-2 and other dilemas / Controversias en neuroinmunología: esclerosis múltiple, vacunación, SARS-CoV-2 y otros dilemas

Neuroimmunology is a discipline that increasingly broadens its horizons in the understanding of neurological diseases. At the same time, and in front of the pathophysiological links of neurological diseases and immunology, specific diagnostic and therapeutic approaches have been proposed. Despite the important advances in this discipline, there are multiple dilemmas that concern and filter into clinical practice. This article presents 15 controversies and a discussion about them, which are built with the most up-to-date evidence available. The topics included in this review are: steroid decline in relapses of multiple sclerosis; therapeutic recommendations in MS in light of the SARS-CoV-2 pandemic; evidence of vaccination in multiple sclerosis and other demyelinating diseases; overview current situation of isolated clinical and radiological syndrome; therapeutic failure in multiple sclerosis, as well as criteria for suspension of disease-modifying therapies; evidence of the management of mild relapses in multiple sclerosis; recommendations for prophylaxis against Strongyloides stercolaris; usefulness of a second course of immunoglobulin in the Guillain-Barré syndrome; criteria to differentiate an acute-onset inflammatory demyelinating chronic polyneuropathy versus Guillain-Barré syndrome; and, the utility of angiotensin-converting enzyme in neurosarcoidosis. In each of the controversies, the general problem is presented, and specific recommendations are offered that can be adopted in daily clinical practice.

La neuroinmunología es una disciplina que cada vez amplía más sus horizontes en la comprensión de las enfermedades neurológicas. Contemporáneamente, y a la luz de los nexos fisiopatológicos de las enfermedades neurológicas y la inmunología, se han planteado enfoques diagnósticos y terapéuticos específicos. A pesar de los importantes avances de esta disciplina, existen múltiples dilemas que le conciernen y se filtran en la práctica clínica. En esta revisión, se presentan y discuten 15 controversias, las cuales se construyen con la información clínica disponible más actualizada. Los temas incluidos son: disminución de esteroides en recaídas de esclerosis múltiple; recomendaciones terapéuticas en esclerosis múltiple a la luz de la pandemia por el SARS-CoV-2; evidencia de vacunación en esclerosis múltiple y en otras enfermedades desmielinizantes; panorama actual del síndrome clínico y radiológico aislado; y fallas terapéuticas en esclerosis múltiple; además, criterios para suspender las terapias modificadoras de la enfermedad; evidencia del manejo en recaídas leves; recomendaciones para la profilaxis contra Strongyloides stercolaris; utilidad de un segundo ciclo de inmunoglobulina en el síndrome de Guillain-Barré; criterios para diferenciar una polineuropatía crónica desmielinizante inflamatoria de inicio agudo de un síndrome de Guillain-Barré y, utilidad de la enzima convertidora de angiotensina en neurosarcoidosis. En cada una de las controversias, se presenta la problemática general y se ofrecen recomendaciones específicas que pueden adoptarse en la práctica clínica diaria.

Controversias en neuroinmunología: esclerosis múltiple, vacunación, SARS-CoV-2 y otros dilemas / Controversies in neuroimmunology: multiple sclerosis, vaccination, SARS-CoV-2 and other dilemas

La neuroinmunología es una disciplina que cada vez amplía más sus horizontes en la comprensión de las enfermedades neurológicas. Contemporáneamente, y a la luz de los nexos fisiopatológicos de las enfermedades neurológicas y la inmunología, se han planteado enfoques diagnósticos y terapéuticos específicos. A pesar de los importantes avances de esta disciplina, existen múltiples dilemas que le conciernen y se filtran en la práctica clínica. En esta revisión, se presentan y discuten 15 controversias, las cuales se construyen con la información clínica disponible más actualizada. Los temas incluidos son: disminución de esteroides en recaídas de esclerosis múltiple; recomendaciones terapéuticas en esclerosis múltiple a la luz de la pandemia por el SARS-CoV-2; evidencia de vacunación en esclerosis múltiple y en otras enfermedades desmielinizantes; panorama actual del síndrome clínico y radiológico aislado; y fallas terapéuticas en esclerosis múltiple; además, criterios para suspender las terapias modificadoras de la enfermedad; evidencia del manejo en recaídas leves; recomendaciones para la profilaxis contra Strongyloides stercolaris; utilidad de un segundo ciclo de inmunoglobulina en el síndrome de Guillain-Barré; criterios para diferenciar una polineuropatía crónica desmielinizante inflamatoria de inicio agudo de un síndrome de Guillain-Barré y, utilidad de la enzima convertidora de angiotensina en neurosarcoidosis. En cada una de las controversias, se presenta la problemática general y se ofrecen recomendaciones específicas que pueden adoptarse en la práctica clínica diaria.

Neuroimmunology is a discipline that increasingly broadens its horizons in the understanding of neurological diseases. At the same time, and in front of the pathophysiological links of neurological diseases and immunology, specific diagnostic and therapeutic approaches have been proposed. Despite the important advances in this discipline, there are multiple dilemmas that concern and filter into clinical practice. This article presents 15 controversies and a discussion about them, which are built with the most up-to-date evidence available. The topics included in this review are: steroid decline in relapses of multiple sclerosis; therapeutic recommendations in MS in light of the SARS-CoV-2 pandemic; evidence of vaccination in multiple sclerosis and other demyelinating diseases; overview current situation of isolated clinical and radiological syndrome; therapeutic failure in multiple sclerosis, as well as criteria for suspension of disease-modifying therapies; evidence of the management of mild relapses in multiple sclerosis; recommendations for prophylaxis against Strongyloides stercolaris; usefulness of a second course of immunoglobulin in the Guillain-Barré syndrome; criteria to differentiate an acute-onset inflammatory demyelinating chronic polyneuropathy versus Guillain-Barré syndrome; and, the utility of angiotensin-converting enzyme in neurosarcoidosis. In each of the controversies, the general problem is presented, and specific recommendations are offered that can be adopted in daily clinical practice.

Vitamin D and other environmental risk factors in Colombian patients with multiple sclerosis.

OBJECTIVE: The aim of this study was to explore the association between MS and vitamin D levels, as well as Epstein-Barr virus (EBV) seropositivity and smoking history in a Colombian population. METHODS: We conducted a cross-sectional study between 2017 and 2018. We measured vitamin D levels and EBV antibody titers and administered a questionnaire to assess dietary habits, smoking, second-hand smoking and duration of smoking, sunlight exposure, physical activity, and personal and family history in individuals with and without multiple sclerosis during adolescence. A multivariable logistic regression model was then performed to explore the association between vitamin D status and MS. RESULTS: A total of 87 individuals with MS (mean age 40.9 years; 65.52% females) and 87 without MS (mean age 55 years; 65.52% females) were included in the analysis. In the multivariable analysis, after controlling for supplementation vitamin D levels did not differ between both groups and no difference was found regarding tobacco smoke exposure. The proportion of individuals who tested positive for anti-EBV nuclear antigen was significantly higher in individuals with MS (95.4% vs 82.76%, p = 0.028) CONCLUSION: : We did not find a statistically significant association between MS and vitamin D levels while anti-EBV nuclear antigen titers behaved as previously described in the literature. This study provides new evidence of the association between MS and different risk factors in our country, reinforcing the hypothesis that the pathogenesis of MS is multifactorial. Further studies are needed to better define the association between environmental factors and the development of MS in low prevalence areas.

Impulsivity traits in patients with multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is a demyelinating disease with a lifetime prevalence of 4.41/100000 in Bogota, Colombia. It is known that it can be related with neuropsychiatric disorders, increasing by a factor of three the prevalence of depression in MS patients compared to general population. However, less attention has been given to the association between MS and impulsive behavior. METHODS: This cross-sectional study compared the levels of impulsivity controlling for the presence of MS. 60 patients with MS and 60 sex- and age-matched subjects without MS were included. In order to assess depression and impulsivity, participants completed the 13-item short form of the Beck Depression Inventory (BDI-SF), the self-report Barratt Impulsiveness Scale version 11 (BIS-11) and the Immediate and Delayed Memory Tasks (IMT-DMT) as an objective measure of impulsive behavior. RESULTS: Total scores, motor and cognitive subscales on the BIS-11 were significantly higher in the MS group. However, median BDI-SF score was also higher in MS patients than in subjects without MS (p < 0.001). To rule out depression as a confounding factor, stratification was performed using the BDI-SF score. In the subgroup of individuals with a BDI-SF< 8, the BIS-11 cognitive subscale scores were significantly higher in patients with MS than in subjects without MS (p = 0.041). In the IMT/DMT test, subjects with MS had a fewer number of correct detections than did subjects without MS, after controlling for BDI-SF score (p = 0.0001/p = 0.003). The ratio of commission errors to correct detections in the IMT was significantly higher in the MS group (p = 0.011). CONCLUSION: Patients with MS showed higher levels of cognitive impulsivity than subjects without MS. Objective measures for impulsiveness further support this finding. Impulsiveness scales scores might be biased by depression, which should be considered when assessing impulsivity in MS.

Seronegative Paraneoplastic Limbic Encephalitis Associated with Thymoma.

Paraneoplastic limbic encephalitis is an autoimmune syndrome characterized by the acute or subacute onset of encephalopathy, memory loss, confusion, temporal lobe seizures, and behavioral and mood changes. Although most patients with paraneoplastic limbic encephalitis have antineuronal antibodies, advances in the field now permit the diagnosis without autoantibody test results. In this case illustrating the new diagnostic criteria, we report a 70-year-old woman who was brought to the emergency room after the acute onset of cognitive impairment, altered mental status, and choreoathetoid movements. Brain magnetic resonance imaging showed hyperintense signals in both temporal lobes, and a chest computed tomogram revealed a thymoma. Because the patient met current diagnostic criteria for autoimmune limbic encephalitis, we were able to start treatment before her antibody tests were processed. The patient received immunotherapy and her tumor was resected. Her choreoathetoid movements disappeared and her other neurologic symptoms improved. Her cerebrospinal fluid proved to be negative for paraneoplastic limbic encephalitis antibodies. Most but not all patients with paraneoplastic limbic encephalitis associated with thymoma have evidence of paraneoplastic antibodies. Prompt management of the underlying malignancy determines whether patients survive and may minimize future cognitive and functional impairment. Practicing neurologists and psychiatrists should be aware of this diagnosis.

HLA-DRB1*14 is a protective allele for multiple sclerosis in an admixed Colombian population.

OBJECTIVE: The aim of this study was to determine ancestry informative markers, mitochondrial DNA haplogroups, and the association between HLA-DRB1 alleles and multiple sclerosis (MS) in a group of patients from Bogotá, Colombia. METHODS: In this case-control study, genomic DNA was isolated and purified from blood samples. HLA-DRB1 allele genotyping was done using PCR. Mitochondrial hypervariable region 1 was amplified and haplogroups were determined using HaploGrep software. Genomic ancestry was estimated by genotyping a panel of ancestry informative markers. To test the association of HLA polymorphisms and MS, we ran separate multivariate logistic regression models. Bonferroni correction was used to account for multiple regression tests. RESULTS: A total of 100 patients with MS (mean age 40.4 ± 12 years; 70% females) and 200 healthy controls (mean age 37.6 ± 11 years; 83.5% females) were included in the analysis. Ancestry proportions and haplogroup frequencies did not differ between patients and controls. HLA-DRB1*15 was present in 31% of cases and 13.5% of controls, whereas HLA-DRB1*14 was present in 5% of cases and 15.5% of controls. In the multivariate model, HLA-DRB1*15 was significantly associated with MS (odds ratio [OR] = 3.05, p < 0.001), whereas HLA-DRB1*14 was confirmed as a protective factor in our population (OR = 0.16, p = 0.001). CONCLUSIONS: This study provides evidence indicating that HLA-DRB1*15 allele confers susceptibility to MS and HLA-DRB1*14 allele exerts resistance to MS in a highly admixed population. This latter finding could partially explain the low prevalence of MS in Bogotá, Colombia.

Tissue-type plasminogen activator triggers the synaptic vesicle cycle in cerebral cortical neurons.

The active zone (AZ) is a thickening of the presynaptic membrane where exocytosis takes place. Chemical synapses contain neurotransmitter-loaded synaptic vesicles (SVs) that at rest are tethered away from the synaptic release site, but after the presynaptic inflow of Ca(+2) elicited by an action potential translocate to the AZ to release their neurotransmitter load. We report that tissue-type plasminogen activator (tPA) is stored outside the AZ of cerebral cortical neurons, either intermixed with small clear-core vesicles or in direct contact with the presynaptic membrane. We found that cerebral ischemia-induced release of neuronal tPA, or treatment with recombinant tPA, recruits the cytoskeletal protein ßII-spectrin to the AZ and promotes the binding of SVs to ßII-spectrin, enlarging the population of SVs in proximity to the synaptic release site. This effect does not require the generation of plasmin and is followed by the recruitment of voltage gated calcium channels (VGCC) to the presynaptic terminal that leads to Ca(+2)-dependent synapsin I phosphorylation, freeing SVs to translocate to the AZ to deliver their neurotransmitter load. Our studies indicate that tPA activates the SV cycle and induces the structural and functional changes in the synapse that are required for successful neurotransmission.