Anti-CD20 and COVID-19 in multiple sclerosis and related disorders: A case series of 60 patients from Madrid, Spain Dear Editor, We have read with great interest the case report of a patient with Multiple Sclerosis (MS) treated with ocrelizumab that developed COVID-19 without serious complications (Novi et al., 2020). The authors suggest a potential protective effect for severe complications of COVID-19 of anti-CD20 drugs. Besides, Prof. Giovannoni's editorial reviews the evidence supporting the hypothesis that immunosuppression of patients with MS on certain disease-modifying therapies may protect of severe COVID-19 infection (Giovannoni, 2020). These data contradict the first assumption that patients with MS on immunosuppressive therapies could be at risk of severe complications of COVID-19.We aimed to analyze the frequency and severity of COVID-19 in our series of patients treated with anti-CD20 in a tertiary hospital in Madrid, Spain, one of the regions worst affected by the pandemic. All patients were contacted by phone from 28 th to 29 th April 2020 (Matías-Guiu et al., 2020a), when total confirmed cases in the Region of Madrid accounted for 60,765. At the moment of the beginning of the pandemic, 60 patients were treated with anti-CD20 (54 with rituximab and 6 with ocrelizumab). The mean age was 47.21 ± 9.86 years-old in the whole group, 47.09 ± 9.56 in patients with rituximab, and 48.33 ± 12.16 in patients with ocrelizumab. 32 patients were classified as having relapsing-remitting MS (53.3%), 14 (23.3%) as secondary-progressive, 9 (15.0%) as primary-progressive forms and 5 as optic neuromyelitis (8.3%). COVID-19 infection was reported in 9 (15%) in the whole sample, 7 (12,9%) in patients receiving rituximab, and 2 (33,3%) in patients with ocrelizumab. Main clinical characteristics of COVID-19 are depicted in Table 1. Interestingly, all patients with COVID-19 did not show serious complications, despite that a patient required admission to a hospital.We also analyzed the time of administration and the frequency of infection by SARS-CoV2, with no apparent relationship. In this regard, 2 (15.38%) of the 13 patients that received treatment in June-August 2019 were infected; 1 (10%) of 10 patients treated in September-October 2019; 2 (13,3%) of the 15 patients that were treated in November-December 2019; and 4 (20%) of 20 patients that received the treatment in January-February 2020. Two patients had received the first dose with the onset of the pandemic, and no one was infected.

It has been suggested that some individuals may present genetic susceptibility to SARS‐CoV‐2 infection, with particular research interest in variants of the ACE2 and TMPRSS2 genes, involved in viral penetration into cells, in different populations and geographic regions, although insufficient information is currently available. This study addresses the apparently reasonable hypothesis that variants of these genes may modulate viral infectivity, making some individuals more vulnerable than others. Through whole‐exome sequencing, the frequency of exonic variants of the ACE2, TMPRSS2 , and Furin genes was analyzed in relation to presence or absence of SARS‐CoV‐2 infection in a familial multiple sclerosis cohort including 120 individuals from Madrid. The ACE2 gene showed a low level of polymorphism, and none variant was significantly associated with SARS‐CoV‐2 infection. These variants have previously been detected in Italy. While TMPRSS2 is highly polymorphic, the variants found do not coincide with those described in other studies, with the exception of rs75603675, which may be associated with SARS‐CoV‐2 infection. The synonymous variants rs61735792 and rs61735794 showed a significant association with infection. Despite the limited number of patients with SARS‐CoV‐2 infection, some variants, especially in TMPRSS2 , may be associated with COVID‐19.

We aimed to evaluate the frequency and mortality of COVID-19 in patients with Alzheimer’s disease (AD) and frontotemporal dementia (FTD). We conducted an observational case series. We enrolled 204 patients, 15.2% of whom were diagnosed with COVID-19, and 41.9% of patients with the infection died. Patients with AD were older than patients with FTD (80.36±8.77 versus 72.00±8.35 years old) and had a higher prevalence of arterial hypertension (55.8% versus 26.3%). COVID-19 occurred in 7.3% of patients living at home, but 72.0% of those living at care homes. Living in care facilities and diagnosis of AD were independently associated with a higher probability of death. We found that living in care homes is the most relevant factor for an increased risk of COVID-19 infection and death, with AD patients exhibiting a higher risk than those with FTD.

BackgroundCognitive impairment is frequent and disabling in multiple sclerosis (MS). Changes in information processing speed constitute the most important cognitive deficit in MS. However, given the clinical and topographical variability of the disease, cognitive impairment may vary greatly and appear in other forms in addition to slower information processing speed. Our aim was to determine the frequency of cognitive impairment, the principal cognitive domains, and components involved in MS and to identify factors associated with presence of cognitive impairment in these patients in a large series of patients.MethodsCross-sectional study of 311 patients with MS [236 with relapsing-remitting MS (RRMS), 52 with secondary progressive MS (SPMS), and 23 with primary progressive MS (PPMS)]. Patients’ cognitive function was assessed with a comprehensive neuropsychological assessment protocol. Patients displaying deficits in 2 or more cognitive domains were considered to have cognitive impairment associated with MS. We conducted a principal component analysis to detect different cognitive patterns by identifying clusters of tests highly correlated to one another.ResultsCognitive impairment was detected in 41.5% of the sample, and it was more frequent in patients with SPMS and PPMS (P = 0.002). Expanded Disability Status Scale scores and education were independent predictors of cognitive impairment. Principal component analysis identified seven clusters: attention and basic executive function (including information processing speed), planning and high-level executive function, verbal memory and language, executive and visuospatial performance time, fatigue-depression, visuospatial function, and basic attention and verbal/visual working memory. Mean scoring of components 2 (high-order executive functioning) and 3 (verbal memory-language) was higher in patients with RRMS than in those with PPMS (component 2) and SPMS (component 3).ConclusionMS is linked to multiple cognitive profiles and disturbances in different domains. This suggests that cognitive alterations in MS are heterogeneous and affect other domains in addition to information processing speed.

IntroductionSeveral experimental studies have suggested the potential remyelinating effects of vitamin D (VitD) supplements regardless of the presence of VitD deficiency. This study aims to analyze neurogenesis in a model of toxic demyelination in order to evaluate the effects of VitD on demyelination and remyelination.Material and methodsWe used 24 male Wistar rats that had received surgical lesions to the corpus callosum and were injected with lysolecithin. Rats were divided into three groups: Group 1 included eight rats with lesions to the corpus callosum but not lysolecithin injections (sham group), group 2 included eight rats with lesions to the corpus callosum that were injected with lysolecithin (lysolecithin group), and group 3 included eight rats with lesions that were injected with lysolecithin and received VitD (VitD group). We analyzed neurogenesis both in the subventricular zone and at the lesion site.ResultsAdministration of VitD promotes the proliferation and differentiation of neural stem cells in the subventricular zone and the migration of these cells to the lesion site in the corpus callosum; these cells subsequently differentiate into oligodendrocyte lineage cells and produce myelin basic protein. This phenomenon was not caused by microglial activation, which was less marked in rats receiving VitD. Megalin expression did not increase at the lesion site, which suggests that VitD is internalized by other mechanisms.ConclusionOur results support the hypothesis that regardless of the presence of VitD deficiency, treatment with VitD may contribute to remyelination by promoting the proliferation of oligodendrocyte precursor cells.

Background: Primary progressive aphasia (PPA) is a clinical syndrome characterized by the neurodegeneration of language brain systems. Three main clinical forms (non-fluent, semantic, and logopenic PPA) have been recognized, but applicability of the classification and the capacity to predict the underlying pathology is controversial. We aimed to study FDG-PET imaging data in a large consecutive case series of patients with PPA to cluster them into different subtypes according to regional brain metabolism.Methods: 122 FDG-PET imaging studies belonging to 91 PPA patients and 28 healthy controls were included. We developed a hierarchical agglomerative cluster analysis with Ward's linkage method, an unsupervised clustering algorithm. We conducted voxel-based brain mapping analysis to evaluate the patterns of hypometabolism of each identified cluster.Results: Cluster analysis confirmed the three current PPA variants, but the optimal number of clusters according to Davies-Bouldin index was 6 subtypes of PPA. This classification resulted from splitting non-fluent variant into three subtypes, while logopenic PPA was split into two subtypes. Voxel-brain mapping analysis displayed different patterns of hypometabolism for each PPA group. New subtypes also showed a different clinical course and were predictive of amyloid imaging results.Conclusion: Our study found that there are more than the three already recognized subtypes of PPA. These new subtypes were more predictive of clinical course and showed different neuroimaging patterns. Our results support the usefulness of FDG-PET in evaluating PPA, and the applicability of computational methods in the analysis of brain metabolism for improving the classification of neurodegenerative disorders.

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We have identified two main patterns of brain metabolism with an association to cognitive status. Only a subgroup of patients showed an increased uptake of the amyloid tracer. Our results suggest that ALS is heterogeneous from a clinical, metabolic, and molecular standpoint.